solana/runtime/src/bank.rs

//! The `bank` module tracks client accounts and the progress of on-chain
//! programs. It offers a high-level API that signs transactions
//! on behalf of the caller, and a low-level API for when they have
//! already been signed and verified.
use crate::{
    accounts::{
        AccountAddressFilter, Accounts, TransactionAccounts, TransactionLoadResult,
        TransactionLoaders,
    },
    accounts_db::{ErrorCounters, SnapshotStorages},
    accounts_index::Ancestors,
    blockhash_queue::BlockhashQueue,
    builtin_programs::{get_builtin_programs, get_epoch_activated_builtin_programs},
    epoch_stakes::{EpochStakes, NodeVoteAccounts},
    log_collector::LogCollector,
    message_processor::MessageProcessor,
    nonce_utils,
    rent_collector::RentCollector,
    stakes::Stakes,
    status_cache::{SlotDelta, StatusCache},
    system_instruction_processor::{get_system_account_kind, SystemAccountKind},
    transaction_batch::TransactionBatch,
    transaction_utils::OrderedIterator,
};
use byteorder::{ByteOrder, LittleEndian};
use itertools::Itertools;
use log::*;
use solana_measure::measure::Measure;
use solana_metrics::{
    datapoint_debug, inc_new_counter_debug, inc_new_counter_error, inc_new_counter_info,
};
use solana_sdk::{
    account::Account,
    clock::{
        Epoch, Slot, SlotCount, SlotIndex, UnixTimestamp, DEFAULT_TICKS_PER_SECOND,
        MAX_PROCESSING_AGE, MAX_RECENT_BLOCKHASHES, SECONDS_PER_DAY,
    },
    entrypoint_native::ProcessInstruction,
    epoch_info::EpochInfo,
    epoch_schedule::EpochSchedule,
    fee_calculator::{FeeCalculator, FeeRateGovernor},
    genesis_config::{GenesisConfig, OperatingMode},
    hard_forks::HardForks,
    hash::{extend_and_hash, hashv, Hash},
    incinerator,
    inflation::Inflation,
    native_loader, nonce,
    program_utils::limited_deserialize,
    pubkey::Pubkey,
    signature::{Keypair, Signature},
    slot_hashes::SlotHashes,
    slot_history::SlotHistory,
    system_transaction,
    sysvar::{self, Sysvar},
    timing::years_as_slots,
    transaction::{Result, Transaction, TransactionError},
};
use solana_stake_program::stake_state::{self, Delegation, PointValue};
use solana_vote_program::{vote_instruction::VoteInstruction, vote_state::VoteState};
use std::{
    cell::RefCell,
    collections::{HashMap, HashSet},
    convert::TryFrom,
    mem,
    ops::RangeInclusive,
    path::PathBuf,
    ptr,
    rc::Rc,
    sync::atomic::{AtomicBool, AtomicU64, Ordering},
    sync::{Arc, RwLock, RwLockReadGuard},
};

pub const SECONDS_PER_YEAR: f64 = 365.25 * 24.0 * 60.0 * 60.0;

pub const MAX_LEADER_SCHEDULE_STAKES: Epoch = 5;

type BankStatusCache = StatusCache<Result<()>>;
#[frozen_abi(digest = "BHtoJzwGJ1seQ2gZmtPSLLgdvq3gRZMj5mpUJsX4wGHT")]
pub type BankSlotDelta = SlotDelta<Result<()>>;
type TransactionAccountRefCells = Vec<Rc<RefCell<Account>>>;
type TransactionLoaderRefCells = Vec<Vec<(Pubkey, RefCell<Account>)>>;

// Eager rent collection repeats in cyclic manner.
// Each cycle is composed of <partiion_count> number of tiny pubkey subranges
// to scan, which is always multiple of the number of slots in epoch.
type PartitionIndex = u64;
type PartitionsPerCycle = u64;
type Partition = (PartitionIndex, PartitionIndex, PartitionsPerCycle);
type RentCollectionCycleParams = (
    Epoch,
    SlotCount,
    bool,
    Epoch,
    EpochCount,
    PartitionsPerCycle,
);

type EpochCount = u64;

#[derive(Default)]
pub struct BankRc {
    /// where all the Accounts are stored
    pub accounts: Arc<Accounts>,

    /// Previous checkpoint of this bank
    pub(crate) parent: RwLock<Option<Arc<Bank>>>,

    /// Current slot
    pub(crate) slot: Slot,
}

#[cfg(RUSTC_WITH_SPECIALIZATION)]
use solana_sdk::abi_example::AbiExample;
#[cfg(RUSTC_WITH_SPECIALIZATION)]
impl AbiExample for BankRc {
    fn example() -> Self {
        BankRc {
            // Set parent to None to cut the recursion into another Bank
            parent: RwLock::new(None),
            // AbiExample for Accounts is specially implemented to contain a storage example
            accounts: AbiExample::example(),
            slot: AbiExample::example(),
        }
    }
}

impl BankRc {
    pub(crate) fn new(accounts: Accounts, slot: Slot) -> Self {
        Self {
            accounts: Arc::new(accounts),
            parent: RwLock::new(None),
            slot,
        }
    }

    pub fn get_snapshot_storages(&self, slot: Slot) -> SnapshotStorages {
        self.accounts.accounts_db.get_snapshot_storages(slot)
    }
}

#[derive(Default, AbiExample)]
pub struct StatusCacheRc {
    /// where all the Accounts are stored
    /// A cache of signature statuses
    pub status_cache: Arc<RwLock<BankStatusCache>>,
}

impl StatusCacheRc {
    pub fn slot_deltas(&self, slots: &[Slot]) -> Vec<BankSlotDelta> {
        let sc = self.status_cache.read().unwrap();
        sc.slot_deltas(slots)
    }

    pub fn roots(&self) -> Vec<Slot> {
        self.status_cache
            .read()
            .unwrap()
            .roots()
            .iter()
            .cloned()
            .sorted()
            .collect()
    }

    pub fn append(&self, slot_deltas: &[BankSlotDelta]) {
        let mut sc = self.status_cache.write().unwrap();
        sc.append(slot_deltas);
    }
}

pub type EnteredEpochCallback = Box<dyn Fn(&mut Bank) + Sync + Send>;

pub type TransactionProcessResult = (Result<()>, Option<HashAgeKind>);
pub struct TransactionResults {
    pub fee_collection_results: Vec<Result<()>>,
    pub processing_results: Vec<TransactionProcessResult>,
}
pub struct TransactionBalancesSet {
    pub pre_balances: TransactionBalances,
    pub post_balances: TransactionBalances,
}
impl TransactionBalancesSet {
    pub fn new(pre_balances: TransactionBalances, post_balances: TransactionBalances) -> Self {
        assert_eq!(pre_balances.len(), post_balances.len());
        Self {
            pre_balances,
            post_balances,
        }
    }
}
pub type TransactionBalances = Vec<Vec<u64>>;

#[derive(Clone, Debug, Eq, PartialEq)]
pub enum HashAgeKind {
    Extant,
    DurableNonce(Pubkey, Account),
}

impl HashAgeKind {
    pub fn is_durable_nonce(&self) -> bool {
        matches!(self, HashAgeKind::DurableNonce(_, _))
    }
}

// Bank's common fields shared by all supported snapshot versions for deserialization.
// Sync fields with BankFieldsToSerialize! This is paired with it.
// All members are made public to remain Bank's members private and to make versioned deserializer workable on this
#[derive(Clone, Default)]
pub(crate) struct BankFieldsToDeserialize {
    pub(crate) blockhash_queue: BlockhashQueue,
    pub(crate) ancestors: Ancestors,
    pub(crate) hash: Hash,
    pub(crate) parent_hash: Hash,
    pub(crate) parent_slot: Slot,
    pub(crate) hard_forks: HardForks,
    pub(crate) transaction_count: u64,
    pub(crate) tick_height: u64,
    pub(crate) signature_count: u64,
    pub(crate) capitalization: u64,
    pub(crate) max_tick_height: u64,
    pub(crate) hashes_per_tick: Option<u64>,
    pub(crate) ticks_per_slot: u64,
    pub(crate) ns_per_slot: u128,
    pub(crate) genesis_creation_time: UnixTimestamp,
    pub(crate) slots_per_year: f64,
    pub(crate) unused: u64,
    pub(crate) slot: Slot,
    pub(crate) epoch: Epoch,
    pub(crate) block_height: u64,
    pub(crate) collector_id: Pubkey,
    pub(crate) collector_fees: u64,
    pub(crate) fee_calculator: FeeCalculator,
    pub(crate) fee_rate_governor: FeeRateGovernor,
    pub(crate) collected_rent: u64,
    pub(crate) rent_collector: RentCollector,
    pub(crate) epoch_schedule: EpochSchedule,
    pub(crate) inflation: Inflation,
    pub(crate) stakes: Stakes,
    pub(crate) epoch_stakes: HashMap<Epoch, EpochStakes>,
    pub(crate) is_delta: bool,
}

// Bank's common fields shared by all supported snapshot versions for serialization.
// This is separated from BankFieldsToDeserialize to avoid cloning by using refs.
// So, sync fields with BankFieldsToDeserialize!
// all members are made public to remain Bank private and to make versioned serializer workable on this
pub(crate) struct BankFieldsToSerialize<'a> {
    pub(crate) blockhash_queue: &'a RwLock<BlockhashQueue>,
    pub(crate) ancestors: &'a Ancestors,
    pub(crate) hash: Hash,
    pub(crate) parent_hash: Hash,
    pub(crate) parent_slot: Slot,
    pub(crate) hard_forks: &'a RwLock<HardForks>,
    pub(crate) transaction_count: u64,
    pub(crate) tick_height: u64,
    pub(crate) signature_count: u64,
    pub(crate) capitalization: u64,
    pub(crate) max_tick_height: u64,
    pub(crate) hashes_per_tick: Option<u64>,
    pub(crate) ticks_per_slot: u64,
    pub(crate) ns_per_slot: u128,
    pub(crate) genesis_creation_time: UnixTimestamp,
    pub(crate) slots_per_year: f64,
    pub(crate) unused: u64,
    pub(crate) slot: Slot,
    pub(crate) epoch: Epoch,
    pub(crate) block_height: u64,
    pub(crate) collector_id: Pubkey,
    pub(crate) collector_fees: u64,
    pub(crate) fee_calculator: FeeCalculator,
    pub(crate) fee_rate_governor: FeeRateGovernor,
    pub(crate) collected_rent: u64,
    pub(crate) rent_collector: RentCollector,
    pub(crate) epoch_schedule: EpochSchedule,
    pub(crate) inflation: Inflation,
    pub(crate) stakes: &'a RwLock<Stakes>,
    pub(crate) epoch_stakes: &'a HashMap<Epoch, EpochStakes>,
    pub(crate) is_delta: bool,
}

/// Manager for the state of all accounts and programs after processing its entries.
/// AbiExample is needed even without Serialize/Deserialize; actual (de-)serializeaion
/// are implemented elsewhere for versioning
#[derive(Default, AbiExample)]
pub struct Bank {
    /// References to accounts, parent and signature status
    pub rc: BankRc,

    pub src: StatusCacheRc,

    /// FIFO queue of `recent_blockhash` items
    blockhash_queue: RwLock<BlockhashQueue>,

    /// The set of parents including this bank
    pub ancestors: Ancestors,

    /// Hash of this Bank's state. Only meaningful after freezing.
    hash: RwLock<Hash>,

    /// Hash of this Bank's parent's state
    parent_hash: Hash,

    /// parent's slot
    parent_slot: Slot,

    /// slots to hard fork at
    hard_forks: Arc<RwLock<HardForks>>,

    /// The number of transactions processed without error
    transaction_count: AtomicU64,

    /// Bank tick height
    tick_height: AtomicU64,

    /// The number of signatures from valid transactions in this slot
    signature_count: AtomicU64,

    /// Total capitalization, used to calculate inflation
    capitalization: AtomicU64,

    // Bank max_tick_height
    max_tick_height: u64,

    /// The number of hashes in each tick. None value means hashing is disabled.
    hashes_per_tick: Option<u64>,

    /// The number of ticks in each slot.
    ticks_per_slot: u64,

    /// length of a slot in ns
    ns_per_slot: u128,

    /// genesis time, used for computed clock
    genesis_creation_time: UnixTimestamp,

    /// The number of slots per year, used for inflation
    slots_per_year: f64,

    /// Unused
    unused: u64,

    /// Bank slot (i.e. block)
    slot: Slot,

    /// Bank epoch
    epoch: Epoch,

    /// Bank block_height
    block_height: u64,

    /// The pubkey to send transactions fees to.
    collector_id: Pubkey,

    /// Fees that have been collected
    collector_fees: AtomicU64,

    /// Latest transaction fees for transactions processed by this bank
    fee_calculator: FeeCalculator,

    /// Track cluster signature throughput and adjust fee rate
    fee_rate_governor: FeeRateGovernor,

    /// Rent that have been collected
    collected_rent: AtomicU64,

    /// latest rent collector, knows the epoch
    rent_collector: RentCollector,

    /// initialized from genesis
    epoch_schedule: EpochSchedule,

    /// inflation specs
    inflation: Arc<RwLock<Inflation>>,

    /// cache of vote_account and stake_account state for this fork
    stakes: RwLock<Stakes>,

    /// staked nodes on epoch boundaries, saved off when a bank.slot() is at
    ///   a leader schedule calculation boundary
    epoch_stakes: HashMap<Epoch, EpochStakes>,

    /// A boolean reflecting whether any entries were recorded into the PoH
    /// stream for the slot == self.slot
    is_delta: AtomicBool,

    /// The Message processor
    message_processor: MessageProcessor,

    /// Callback to be notified when a bank enters a new Epoch
    /// (used to adjust cluster features over time)
    entered_epoch_callback: Arc<RwLock<Option<EnteredEpochCallback>>>,

    /// Last time when the cluster info vote listener has synced with this bank
    pub last_vote_sync: AtomicU64,

    /// Rewards that were paid out immediately after this bank was created
    pub rewards: Option<Vec<(Pubkey, i64)>>,

    pub skip_drop: AtomicBool,

    pub operating_mode: Option<OperatingMode>,

    pub lazy_rent_collection: AtomicBool,
}

impl Default for BlockhashQueue {
    fn default() -> Self {
        Self::new(MAX_RECENT_BLOCKHASHES)
    }
}

impl Bank {
    pub fn new(genesis_config: &GenesisConfig) -> Self {
        Self::new_with_paths(&genesis_config, Vec::new(), &[])
    }

    pub fn new_with_paths(
        genesis_config: &GenesisConfig,
        paths: Vec<PathBuf>,
        frozen_account_pubkeys: &[Pubkey],
    ) -> Self {
        let mut bank = Self::default();
        bank.operating_mode = Some(genesis_config.operating_mode);
        bank.ancestors.insert(bank.slot(), 0);

        bank.rc.accounts = Arc::new(Accounts::new(paths));
        bank.process_genesis_config(genesis_config);
        bank.finish_init();

        // Freeze accounts after process_genesis_config creates the initial append vecs
        Arc::get_mut(&mut Arc::get_mut(&mut bank.rc.accounts).unwrap().accounts_db)
            .unwrap()
            .freeze_accounts(&bank.ancestors, frozen_account_pubkeys);

        // genesis needs stakes for all epochs up to the epoch implied by
        //  slot = 0 and genesis configuration
        {
            let stakes = bank.stakes.read().unwrap();
            for epoch in 0..=bank.get_leader_schedule_epoch(bank.slot) {
                bank.epoch_stakes
                    .insert(epoch, EpochStakes::new(&stakes, epoch));
            }
            bank.update_stake_history(None);
        }
        bank.update_clock();
        bank.update_rent();
        bank.update_epoch_schedule();
        bank.update_recent_blockhashes();
        if bank.operating_mode == Some(OperatingMode::Stable) {
            bank.message_processor.set_cross_program_support(false);
        }
        bank
    }

    /// Create a new bank that points to an immutable checkpoint of another bank.
    pub fn new_from_parent(parent: &Arc<Bank>, collector_id: &Pubkey, slot: Slot) -> Self {
        parent.freeze();
        assert_ne!(slot, parent.slot());

        let rc = BankRc {
            accounts: Arc::new(Accounts::new_from_parent(
                &parent.rc.accounts,
                slot,
                parent.slot(),
            )),
            parent: RwLock::new(Some(parent.clone())),
            slot,
        };
        let src = StatusCacheRc {
            status_cache: parent.src.status_cache.clone(),
        };
        let epoch_schedule = parent.epoch_schedule;
        let epoch = epoch_schedule.get_epoch(slot);

        let fee_rate_governor =
            FeeRateGovernor::new_derived(&parent.fee_rate_governor, parent.signature_count());

        let mut new = Bank {
            rc,
            src,
            slot,
            epoch,
            blockhash_queue: RwLock::new(parent.blockhash_queue.read().unwrap().clone()),

            // TODO: clean this up, soo much special-case copying...
            hashes_per_tick: parent.hashes_per_tick,
            ticks_per_slot: parent.ticks_per_slot,
            ns_per_slot: parent.ns_per_slot,
            genesis_creation_time: parent.genesis_creation_time,
            unused: parent.unused,
            slots_per_year: parent.slots_per_year,
            epoch_schedule,
            collected_rent: AtomicU64::new(0),
            rent_collector: parent.rent_collector.clone_with_epoch(epoch),
            max_tick_height: (slot + 1) * parent.ticks_per_slot,
            block_height: parent.block_height + 1,
            fee_calculator: fee_rate_governor.create_fee_calculator(),
            fee_rate_governor,
            capitalization: AtomicU64::new(parent.capitalization()),
            inflation: parent.inflation.clone(),
            transaction_count: AtomicU64::new(parent.transaction_count()),
            stakes: RwLock::new(parent.stakes.read().unwrap().clone_with_epoch(epoch)),
            epoch_stakes: parent.epoch_stakes.clone(),
            parent_hash: parent.hash(),
            parent_slot: parent.slot(),
            collector_id: *collector_id,
            collector_fees: AtomicU64::new(0),
            ancestors: HashMap::new(),
            hash: RwLock::new(Hash::default()),
            is_delta: AtomicBool::new(false),
            tick_height: AtomicU64::new(parent.tick_height.load(Ordering::Relaxed)),
            signature_count: AtomicU64::new(0),
            message_processor: parent.message_processor.clone(),
            entered_epoch_callback: parent.entered_epoch_callback.clone(),
            hard_forks: parent.hard_forks.clone(),
            last_vote_sync: AtomicU64::new(parent.last_vote_sync.load(Ordering::Relaxed)),
            rewards: None,
            skip_drop: AtomicBool::new(false),
            operating_mode: parent.operating_mode,
            lazy_rent_collection: AtomicBool::new(
                parent.lazy_rent_collection.load(Ordering::Relaxed),
            ),
        };

        datapoint_info!(
            "bank-new_from_parent-heights",
            ("slot_height", slot, i64),
            ("block_height", new.block_height, i64)
        );

        let leader_schedule_epoch = epoch_schedule.get_leader_schedule_epoch(slot);
        if parent.epoch() < new.epoch() {
            if let Some(entered_epoch_callback) =
                parent.entered_epoch_callback.read().unwrap().as_ref()
            {
                entered_epoch_callback(&mut new)
            }

            if let Some(builtin_programs) =
                get_epoch_activated_builtin_programs(new.operating_mode(), new.epoch)
            {
                for program in builtin_programs.iter() {
                    new.add_builtin_program(&program.name, program.id, program.process_instruction);
                }
            }
        }

        new.update_epoch_stakes(leader_schedule_epoch);
        new.ancestors.insert(new.slot(), 0);
        new.parents().iter().enumerate().for_each(|(i, p)| {
            new.ancestors.insert(p.slot(), i + 1);
        });

        new.update_slot_hashes();
        new.update_rewards(parent.epoch());
        new.update_stake_history(Some(parent.epoch()));
        new.update_clock();
        new.update_fees();
        if !new.fix_recent_blockhashes_sysvar_delay() {
            new.update_recent_blockhashes();
        }
        new
    }

    /// Like `new_from_parent` but additionally:
    /// * Doesn't assume that the parent is anywhere near `slot`, parent could be millions of slots
    /// in the past
    /// * Adjusts the new bank's tick height to avoid having to run PoH for millions of slots
    /// * Freezes the new bank, assuming that the user will `Bank::new_from_parent` from this bank
    pub fn warp_from_parent(parent: &Arc<Bank>, collector_id: &Pubkey, slot: Slot) -> Self {
        let mut new = Bank::new_from_parent(parent, collector_id, slot);
        new.update_epoch_stakes(new.epoch_schedule().get_epoch(slot));
        new.tick_height
            .store(new.max_tick_height(), Ordering::Relaxed);
        new.freeze();
        new
    }

    /// Create a bank from explicit arguments and deserialized fields from snapshot
    #[allow(clippy::float_cmp)]
    pub(crate) fn new_from_fields(
        bank_rc: BankRc,
        genesis_config: &GenesisConfig,
        fields: BankFieldsToDeserialize,
    ) -> Self {
        fn new<T: Default>() -> T {
            T::default()
        }
        let mut bank = Self {
            rc: bank_rc,
            src: new(),
            blockhash_queue: RwLock::new(fields.blockhash_queue),
            ancestors: fields.ancestors,
            hash: RwLock::new(fields.hash),
            parent_hash: fields.parent_hash,
            parent_slot: fields.parent_slot,
            hard_forks: Arc::new(RwLock::new(fields.hard_forks)),
            transaction_count: AtomicU64::new(fields.transaction_count),
            tick_height: AtomicU64::new(fields.tick_height),
            signature_count: AtomicU64::new(fields.signature_count),
            capitalization: AtomicU64::new(fields.capitalization),
            max_tick_height: fields.max_tick_height,
            hashes_per_tick: fields.hashes_per_tick,
            ticks_per_slot: fields.ticks_per_slot,
            ns_per_slot: fields.ns_per_slot,
            genesis_creation_time: fields.genesis_creation_time,
            slots_per_year: fields.slots_per_year,
            unused: genesis_config.unused,
            slot: fields.slot,
            epoch: fields.epoch,
            block_height: fields.block_height,
            collector_id: fields.collector_id,
            collector_fees: AtomicU64::new(fields.collector_fees),
            fee_calculator: fields.fee_calculator,
            fee_rate_governor: fields.fee_rate_governor,
            collected_rent: AtomicU64::new(fields.collected_rent),
            rent_collector: fields.rent_collector,
            epoch_schedule: fields.epoch_schedule,
            inflation: Arc::new(RwLock::new(fields.inflation)),
            stakes: RwLock::new(fields.stakes),
            epoch_stakes: fields.epoch_stakes,
            is_delta: AtomicBool::new(fields.is_delta),
            message_processor: new(),
            entered_epoch_callback: new(),
            last_vote_sync: new(),
            rewards: new(),
            skip_drop: new(),
            operating_mode: Some(genesis_config.operating_mode),
            lazy_rent_collection: new(),
        };
        bank.finish_init();

        // Sanity assertions between bank snapshot and genesis config
        // Consider removing from serializable bank state ([Ref]BankFields) and initializing
        // from the passed in genesis_config instead (as new()/new_with_paths() already do)
        assert_eq!(
            bank.hashes_per_tick,
            genesis_config.poh_config.hashes_per_tick
        );
        assert_eq!(bank.ticks_per_slot, genesis_config.ticks_per_slot);
        assert_eq!(
            bank.ns_per_slot,
            genesis_config.poh_config.target_tick_duration.as_nanos()
                * genesis_config.ticks_per_slot as u128
        );
        assert_eq!(bank.genesis_creation_time, genesis_config.creation_time);
        assert_eq!(bank.unused, genesis_config.unused);
        assert_eq!(bank.max_tick_height, (bank.slot + 1) * bank.ticks_per_slot);
        assert_eq!(
            bank.slots_per_year,
            years_as_slots(
                1.0,
                &genesis_config.poh_config.target_tick_duration,
                bank.ticks_per_slot,
            )
        );
        assert_eq!(bank.epoch_schedule, genesis_config.epoch_schedule);
        assert_eq!(bank.epoch, bank.epoch_schedule.get_epoch(bank.slot));
        assert_eq!(
            bank.rent_collector,
            RentCollector::new(
                bank.epoch,
                &bank.epoch_schedule,
                bank.slots_per_year,
                &genesis_config.rent,
            )
        );

        bank
    }

    /// Return subset of bank fields representing serializable state
    pub(crate) fn get_fields_to_serialize(&self) -> BankFieldsToSerialize {
        BankFieldsToSerialize {
            blockhash_queue: &self.blockhash_queue,
            ancestors: &self.ancestors,
            hash: *self.hash.read().unwrap(),
            parent_hash: self.parent_hash,
            parent_slot: self.parent_slot,
            hard_forks: &*self.hard_forks,
            transaction_count: self.transaction_count.load(Ordering::Relaxed),
            tick_height: self.tick_height.load(Ordering::Relaxed),
            signature_count: self.signature_count.load(Ordering::Relaxed),
            capitalization: self.capitalization.load(Ordering::Relaxed),
            max_tick_height: self.max_tick_height,
            hashes_per_tick: self.hashes_per_tick,
            ticks_per_slot: self.ticks_per_slot,
            ns_per_slot: self.ns_per_slot,
            genesis_creation_time: self.genesis_creation_time,
            slots_per_year: self.slots_per_year,
            unused: self.unused,
            slot: self.slot,
            epoch: self.epoch,
            block_height: self.block_height,
            collector_id: self.collector_id,
            collector_fees: self.collector_fees.load(Ordering::Relaxed),
            fee_calculator: self.fee_calculator.clone(),
            fee_rate_governor: self.fee_rate_governor.clone(),
            collected_rent: self.collected_rent.load(Ordering::Relaxed),
            rent_collector: self.rent_collector.clone(),
            epoch_schedule: self.epoch_schedule,
            inflation: *self.inflation.read().unwrap(),
            stakes: &self.stakes,
            epoch_stakes: &self.epoch_stakes,
            is_delta: self.is_delta.load(Ordering::Relaxed),
        }
    }

    pub fn collector_id(&self) -> &Pubkey {
        &self.collector_id
    }

    pub fn slot(&self) -> Slot {
        self.slot
    }

    pub fn epoch(&self) -> Epoch {
        self.epoch
    }

    pub fn first_normal_epoch(&self) -> Epoch {
        self.epoch_schedule.first_normal_epoch
    }

    pub fn freeze_lock(&self) -> RwLockReadGuard<Hash> {
        self.hash.read().unwrap()
    }

    pub fn hash(&self) -> Hash {
        *self.hash.read().unwrap()
    }

    pub fn is_frozen(&self) -> bool {
        *self.hash.read().unwrap() != Hash::default()
    }

    pub fn status_cache_ancestors(&self) -> Vec<u64> {
        let mut roots = self.src.status_cache.read().unwrap().roots().clone();
        let min = roots.iter().min().cloned().unwrap_or(0);
        for ancestor in self.ancestors.keys() {
            if *ancestor >= min {
                roots.insert(*ancestor);
            }
        }

        let mut ancestors: Vec<_> = roots.into_iter().collect();
        ancestors.sort();
        ancestors
    }

    /// computed unix_timestamp at this slot height
    pub fn unix_timestamp(&self) -> i64 {
        self.genesis_creation_time + ((self.slot as u128 * self.ns_per_slot) / 1_000_000_000) as i64
    }

    fn update_sysvar_account<F>(&self, pubkey: &Pubkey, updater: F)
    where
        F: Fn(&Option<Account>) -> Account,
    {
        let old_account = self.get_sysvar_account(pubkey);
        let new_account = updater(&old_account);
        self.store_account(pubkey, &new_account);
    }

    fn inherit_sysvar_account_balance(&self, old_account: &Option<Account>) -> u64 {
        old_account.as_ref().map(|a| a.lamports).unwrap_or(1)
    }

    /// Unused conversion
    pub fn get_unused_from_slot(rooted_slot: Slot, unused: u64) -> u64 {
        (rooted_slot + (unused - 1)) / unused
    }

    pub fn clock(&self) -> sysvar::clock::Clock {
        sysvar::clock::Clock {
            slot: self.slot,
            unused: Self::get_unused_from_slot(self.slot, self.unused),
            epoch: self.epoch_schedule.get_epoch(self.slot),
            leader_schedule_epoch: self.epoch_schedule.get_leader_schedule_epoch(self.slot),
            unix_timestamp: self.unix_timestamp(),
        }
    }

    fn update_clock(&self) {
        self.update_sysvar_account(&sysvar::clock::id(), |account| {
            self.clock()
                .create_account(self.inherit_sysvar_account_balance(account))
        });
    }

    fn update_slot_history(&self) {
        self.update_sysvar_account(&sysvar::slot_history::id(), |account| {
            let mut slot_history = account
                .as_ref()
                .map(|account| SlotHistory::from_account(&account).unwrap())
                .unwrap_or_default();
            slot_history.add(self.slot());
            slot_history.create_account(self.inherit_sysvar_account_balance(account))
        });
    }

    fn update_slot_hashes(&self) {
        self.update_sysvar_account(&sysvar::slot_hashes::id(), |account| {
            let mut slot_hashes = account
                .as_ref()
                .map(|account| SlotHashes::from_account(&account).unwrap())
                .unwrap_or_default();
            slot_hashes.add(self.parent_slot, self.parent_hash);
            slot_hashes.create_account(self.inherit_sysvar_account_balance(account))
        });
    }

    fn update_epoch_stakes(&mut self, leader_schedule_epoch: Epoch) {
        // update epoch_stakes cache
        //  if my parent didn't populate for this staker's epoch, we've
        //  crossed a boundary
        if self.epoch_stakes.get(&leader_schedule_epoch).is_none() {
            self.epoch_stakes.retain(|&epoch, _| {
                epoch >= leader_schedule_epoch.saturating_sub(MAX_LEADER_SCHEDULE_STAKES)
            });

            let vote_stakes: HashMap<_, _> = self
                .stakes
                .read()
                .unwrap()
                .vote_accounts()
                .iter()
                .map(|(epoch, (stake, _))| (*epoch, *stake))
                .collect();
            let new_epoch_stakes =
                EpochStakes::new(&self.stakes.read().unwrap(), leader_schedule_epoch);
            info!(
                "new epoch stakes, epoch: {}, stakes: {:#?}, total_stake: {}",
                leader_schedule_epoch,
                vote_stakes,
                new_epoch_stakes.total_stake(),
            );
            self.epoch_stakes
                .insert(leader_schedule_epoch, new_epoch_stakes);
        }
    }

    fn update_fees(&self) {
        self.update_sysvar_account(&sysvar::fees::id(), |account| {
            sysvar::fees::create_account(
                self.inherit_sysvar_account_balance(account),
                &self.fee_calculator,
            )
        });
    }

    fn update_rent(&self) {
        self.update_sysvar_account(&sysvar::rent::id(), |account| {
            sysvar::rent::create_account(
                self.inherit_sysvar_account_balance(account),
                &self.rent_collector.rent,
            )
        });
    }

    fn update_epoch_schedule(&self) {
        self.update_sysvar_account(&sysvar::epoch_schedule::id(), |account| {
            sysvar::epoch_schedule::create_account(
                self.inherit_sysvar_account_balance(account),
                &self.epoch_schedule,
            )
        });
    }

    fn update_stake_history(&self, epoch: Option<Epoch>) {
        if epoch == Some(self.epoch()) {
            return;
        }
        // if I'm the first Bank in an epoch, ensure stake_history is updated
        self.update_sysvar_account(&sysvar::stake_history::id(), |account| {
            sysvar::stake_history::create_account(
                self.inherit_sysvar_account_balance(account),
                self.stakes.read().unwrap().history(),
            )
        });
    }

    // update reward for previous epoch
    fn update_rewards(&mut self, epoch: Epoch) {
        if epoch == self.epoch() {
            return;
        }
        // if I'm the first Bank in an epoch, count, claim, disburse rewards from Inflation

        //  years_elapsed =         slots_elapsed                             /     slots/year
        let year = (self.epoch_schedule.get_last_slot_in_epoch(epoch)) as f64 / self.slots_per_year;

        // period: time that has passed as a fraction of a year, basically the length of
        //  an epoch as a fraction of a year
        //  years_elapsed =   slots_elapsed                               /  slots/year
        let period = self.epoch_schedule.get_slots_in_epoch(epoch) as f64 / self.slots_per_year;

        let validator_rewards = {
            let inflation = self.inflation.read().unwrap();

            (*inflation).validator(year) * self.capitalization() as f64 * period
        } as u64;

        let vote_balance_and_staked = self.stakes.read().unwrap().vote_balance_and_staked();

        let validator_point_value = self.pay_validator_rewards(validator_rewards);

        // this sysvar could be retired...
        self.update_sysvar_account(&sysvar::rewards::id(), |account| {
            sysvar::rewards::create_account(
                self.inherit_sysvar_account_balance(account),
                validator_point_value,
            )
        });

        let validator_rewards_paid =
            self.stakes.read().unwrap().vote_balance_and_staked() - vote_balance_and_staked;
        if let Some(rewards) = self.rewards.as_ref() {
            assert_eq!(
                validator_rewards_paid,
                u64::try_from(rewards.iter().map(|(_pubkey, reward)| reward).sum::<i64>()).unwrap()
            );
        }

        // verify that we didn't pay any more than we expected to
        assert!(validator_rewards >= validator_rewards_paid);

        self.capitalization
            .fetch_add(validator_rewards_paid, Ordering::Relaxed);
    }

    /// map stake delegations into resolved (pubkey, account) pairs
    ///  returns a map (has to be copied) of loaded
    ///   ( Vec<(staker info)> (voter account) ) keyed by voter pubkey
    ///
    fn stake_delegation_accounts(&self) -> HashMap<Pubkey, (Vec<(Pubkey, Account)>, Account)> {
        let mut accounts = HashMap::new();

        self.stakes
            .read()
            .unwrap()
            .stake_delegations()
            .iter()
            .for_each(|(stake_pubkey, delegation)| {
                match (
                    self.get_account(&stake_pubkey),
                    self.get_account(&delegation.voter_pubkey),
                ) {
                    (Some(stake_account), Some(vote_account)) => {
                        let entry = accounts
                            .entry(delegation.voter_pubkey)
                            .or_insert((Vec::new(), vote_account));
                        entry.0.push((*stake_pubkey, stake_account));
                    }
                    (_, _) => {}
                }
            });

        accounts
    }

    /// iterate over all stakes, redeem vote credits for each stake we can
    ///   successfully load and parse, return total payout
    fn pay_validator_rewards(&mut self, rewards: u64) -> f64 {
        let stake_history = self.stakes.read().unwrap().history().clone();

        let mut stake_delegation_accounts = self.stake_delegation_accounts();

        let points: u128 = stake_delegation_accounts
            .iter()
            .flat_map(|(_vote_pubkey, (stake_group, vote_account))| {
                stake_group
                    .iter()
                    .map(move |(_stake_pubkey, stake_account)| (stake_account, vote_account))
            })
            .map(|(stake_account, vote_account)| {
                stake_state::calculate_points(&stake_account, &vote_account, Some(&stake_history))
                    .unwrap_or(0)
            })
            .sum();

        if points == 0 {
            return 0.0;
        }

        let point_value = PointValue { rewards, points };

        let mut rewards = HashMap::new();

        // pay according to point value
        for (vote_pubkey, (stake_group, vote_account)) in stake_delegation_accounts.iter_mut() {
            let mut vote_account_changed = false;
            for (stake_pubkey, stake_account) in stake_group.iter_mut() {
                let redeemed = stake_state::redeem_rewards(
                    stake_account,
                    vote_account,
                    &point_value,
                    Some(&stake_history),
                );
                if let Ok((stakers_reward, voters_reward)) = redeemed {
                    self.store_account(&stake_pubkey, &stake_account);
                    vote_account_changed = true;

                    if voters_reward > 0 {
                        *rewards.entry(*vote_pubkey).or_insert(0i64) += voters_reward as i64;
                    }

                    if stakers_reward > 0 {
                        *rewards.entry(*stake_pubkey).or_insert(0i64) += stakers_reward as i64;
                    }
                } else {
                    debug!(
                        "stake_state::redeem_rewards() failed for {}: {:?}",
                        stake_pubkey, redeemed
                    );
                }
            }

            if vote_account_changed {
                self.store_account(&vote_pubkey, &vote_account);
            }
        }

        assert_eq!(self.rewards, None);
        self.rewards = Some(rewards.drain().collect());
        point_value.rewards as f64 / point_value.points as f64
    }

    fn update_recent_blockhashes_locked(&self, locked_blockhash_queue: &BlockhashQueue) {
        self.update_sysvar_account(&sysvar::recent_blockhashes::id(), |account| {
            let recent_blockhash_iter = locked_blockhash_queue.get_recent_blockhashes();
            sysvar::recent_blockhashes::create_account_with_data(
                self.inherit_sysvar_account_balance(account),
                recent_blockhash_iter,
            )
        });
    }

    pub fn update_recent_blockhashes(&self) {
        let blockhash_queue = self.blockhash_queue.read().unwrap();
        self.update_recent_blockhashes_locked(&blockhash_queue);
    }

    fn collect_fees(&self) {
        let collector_fees = self.collector_fees.load(Ordering::Relaxed) as u64;

        if collector_fees != 0 {
            let (unburned, burned) = self.fee_rate_governor.burn(collector_fees);
            // burn a portion of fees
            self.deposit(&self.collector_id, unburned);
            self.capitalization.fetch_sub(burned, Ordering::Relaxed);
        }
    }

    pub fn rehash(&self) {
        let mut hash = self.hash.write().unwrap();
        let new = self.hash_internal_state();
        if new != *hash {
            warn!("Updating bank hash to {}", new);
            *hash = new;
        }
    }

    pub fn freeze(&self) {
        let mut hash = self.hash.write().unwrap();

        if *hash == Hash::default() {
            // finish up any deferred changes to account state
            self.collect_rent_eagerly();
            self.collect_fees();
            self.distribute_rent();
            self.update_slot_history();
            self.run_incinerator();

            // freeze is a one-way trip, idempotent
            *hash = self.hash_internal_state();
        }
    }

    pub fn epoch_schedule(&self) -> &EpochSchedule {
        &self.epoch_schedule
    }

    /// squash the parent's state up into this Bank,
    ///   this Bank becomes a root
    pub fn squash(&self) {
        self.freeze();

        //this bank and all its parents are now on the rooted path
        let mut roots = vec![self.slot()];
        roots.append(&mut self.parents().iter().map(|p| p.slot()).collect());
        *self.rc.parent.write().unwrap() = None;

        let mut squash_accounts_time = Measure::start("squash_accounts_time");
        for slot in roots.iter().rev() {
            // root forks cannot be purged
            self.rc.accounts.add_root(*slot);
        }
        squash_accounts_time.stop();

        let mut squash_cache_time = Measure::start("squash_cache_time");
        roots
            .iter()
            .for_each(|slot| self.src.status_cache.write().unwrap().add_root(*slot));
        squash_cache_time.stop();

        datapoint_debug!(
            "tower-observed",
            ("squash_accounts_ms", squash_accounts_time.as_ms(), i64),
            ("squash_cache_ms", squash_cache_time.as_ms(), i64)
        );
    }

    /// Return the more recent checkpoint of this bank instance.
    pub fn parent(&self) -> Option<Arc<Bank>> {
        self.rc.parent.read().unwrap().clone()
    }

    pub fn parent_slot(&self) -> Slot {
        self.parent_slot
    }

    fn process_genesis_config(&mut self, genesis_config: &GenesisConfig) {
        // Bootstrap validator collects fees until `new_from_parent` is called.
        self.fee_rate_governor = genesis_config.fee_rate_governor.clone();
        self.fee_calculator = self.fee_rate_governor.create_fee_calculator();
        self.update_fees();

        for (pubkey, account) in genesis_config.accounts.iter() {
            if self.get_account(&pubkey).is_some() {
                panic!("{} repeated in genesis config", pubkey);
            }
            self.store_account(pubkey, account);
            self.capitalization
                .fetch_add(account.lamports, Ordering::Relaxed);
        }

        for (pubkey, account) in genesis_config.rewards_pools.iter() {
            if self.get_account(&pubkey).is_some() {
                panic!("{} repeated in genesis config", pubkey);
            }
            self.store_account(pubkey, account);
        }

        // highest staked node is the first collector
        self.collector_id = self
            .stakes
            .read()
            .unwrap()
            .highest_staked_node()
            .unwrap_or_default();

        self.blockhash_queue
            .write()
            .unwrap()
            .genesis_hash(&genesis_config.hash(), &self.fee_calculator);

        self.hashes_per_tick = genesis_config.poh_config.hashes_per_tick;
        self.ticks_per_slot = genesis_config.ticks_per_slot;
        self.ns_per_slot = genesis_config.poh_config.target_tick_duration.as_nanos()
            * genesis_config.ticks_per_slot as u128;
        self.genesis_creation_time = genesis_config.creation_time;
        self.unused = genesis_config.unused;
        self.max_tick_height = (self.slot + 1) * self.ticks_per_slot;
        self.slots_per_year = years_as_slots(
            1.0,
            &genesis_config.poh_config.target_tick_duration,
            self.ticks_per_slot,
        );

        self.epoch_schedule = genesis_config.epoch_schedule;

        self.inflation = Arc::new(RwLock::new(genesis_config.inflation));

        self.rent_collector = RentCollector::new(
            self.epoch,
            &self.epoch_schedule,
            self.slots_per_year,
            &genesis_config.rent,
        );

        // Add additional native programs specified in the genesis config
        for (name, program_id) in &genesis_config.native_instruction_processors {
            self.add_native_program(name, program_id);
        }
    }

    pub fn add_native_program(&self, name: &str, program_id: &Pubkey) {
        let account = native_loader::create_loadable_account(name);
        self.store_account(program_id, &account);
        debug!("Added native program {} under {:?}", name, program_id);
    }

    pub fn set_cross_program_support(&mut self, is_supported: bool) {
        self.message_processor
            .set_cross_program_support(is_supported);
    }

    /// Return the last block hash registered.
    pub fn last_blockhash(&self) -> Hash {
        self.blockhash_queue.read().unwrap().last_hash()
    }

    pub fn get_minimum_balance_for_rent_exemption(&self, data_len: usize) -> u64 {
        self.rent_collector.rent.minimum_balance(data_len)
    }

    pub fn last_blockhash_with_fee_calculator(&self) -> (Hash, FeeCalculator) {
        let blockhash_queue = self.blockhash_queue.read().unwrap();
        let last_hash = blockhash_queue.last_hash();
        (
            last_hash,
            blockhash_queue
                .get_fee_calculator(&last_hash)
                .unwrap()
                .clone(),
        )
    }

    pub fn get_fee_calculator(&self, hash: &Hash) -> Option<FeeCalculator> {
        let blockhash_queue = self.blockhash_queue.read().unwrap();
        blockhash_queue.get_fee_calculator(hash).cloned()
    }

    pub fn get_fee_rate_governor(&self) -> &FeeRateGovernor {
        &self.fee_rate_governor
    }

    pub fn get_blockhash_last_valid_slot(&self, blockhash: &Hash) -> Option<Slot> {
        let blockhash_queue = self.blockhash_queue.read().unwrap();
        // This calculation will need to be updated to consider epoch boundaries if BlockhashQueue
        // length is made variable by epoch
        blockhash_queue
            .get_hash_age(blockhash)
            .map(|age| self.slot + blockhash_queue.len() as u64 - age)
    }

    pub fn confirmed_last_blockhash(&self) -> (Hash, FeeCalculator) {
        const NUM_BLOCKHASH_CONFIRMATIONS: usize = 3;

        let parents = self.parents();
        if parents.is_empty() {
            self.last_blockhash_with_fee_calculator()
        } else {
            let index = NUM_BLOCKHASH_CONFIRMATIONS.min(parents.len() - 1);
            parents[index].last_blockhash_with_fee_calculator()
        }
    }

    /// Forget all signatures. Useful for benchmarking.
    pub fn clear_signatures(&self) {
        self.src.status_cache.write().unwrap().clear_signatures();
    }

    pub fn clear_slot_signatures(&self, slot: Slot) {
        self.src
            .status_cache
            .write()
            .unwrap()
            .clear_slot_signatures(slot);
    }

    pub fn can_commit(result: &Result<()>) -> bool {
        match result {
            Ok(_) => true,
            Err(TransactionError::InstructionError(_, _)) => true,
            Err(_) => false,
        }
    }

    fn update_transaction_statuses(
        &self,
        txs: &[Transaction],
        iteration_order: Option<&[usize]>,
        res: &[TransactionProcessResult],
    ) {
        let mut status_cache = self.src.status_cache.write().unwrap();
        for (i, tx) in OrderedIterator::new(txs, iteration_order).enumerate() {
            let (res, _hash_age_kind) = &res[i];
            if Self::can_commit(res) && !tx.signatures.is_empty() {
                status_cache.insert(
                    &tx.message().recent_blockhash,
                    &tx.signatures[0],
                    self.slot(),
                    res.clone(),
                );
            }
        }
    }

    /// Tell the bank which Entry IDs exist on the ledger. This function
    /// assumes subsequent calls correspond to later entries, and will boot
    /// the oldest ones once its internal cache is full. Once boot, the
    /// bank will reject transactions using that `hash`.
    pub fn register_tick(&self, hash: &Hash) {
        assert!(
            !self.is_frozen(),
            "register_tick() working on a frozen bank!"
        );

        inc_new_counter_debug!("bank-register_tick-registered", 1);
        // Grab blockhash lock before incrementing tick height so that replay stage does
        // not attempt to freeze after observing the last tick and before blockhash is
        // updated
        let mut w_blockhash_queue = self.blockhash_queue.write().unwrap();
        let current_tick_height = self.tick_height.fetch_add(1, Ordering::Relaxed) as u64;
        if self.is_block_boundary(current_tick_height + 1) {
            w_blockhash_queue.register_hash(hash, &self.fee_calculator);
            if self.fix_recent_blockhashes_sysvar_delay() {
                self.update_recent_blockhashes_locked(&w_blockhash_queue);
            }
        }
    }

    pub fn is_complete(&self) -> bool {
        self.tick_height() == self.max_tick_height()
    }

    pub fn is_block_boundary(&self, tick_height: u64) -> bool {
        tick_height % self.ticks_per_slot == 0
    }

    /// Process a Transaction. This is used for unit tests and simply calls the vector
    /// Bank::process_transactions method
    pub fn process_transaction(&self, tx: &Transaction) -> Result<()> {
        let txs = vec![tx.clone()];
        self.process_transactions(&txs)[0].clone()?;
        tx.signatures
            .get(0)
            .map_or(Ok(()), |sig| self.get_signature_status(sig).unwrap())
    }

    pub fn prepare_batch<'a, 'b>(
        &'a self,
        txs: &'b [Transaction],
        iteration_order: Option<Vec<usize>>,
    ) -> TransactionBatch<'a, 'b> {
        let results = self
            .rc
            .accounts
            .lock_accounts(txs, iteration_order.as_deref());
        TransactionBatch::new(results, &self, txs, iteration_order)
    }

    pub fn prepare_simulation_batch<'a, 'b>(
        &'a self,
        txs: &'b [Transaction],
    ) -> TransactionBatch<'a, 'b> {
        let mut batch = TransactionBatch::new(vec![Ok(()); txs.len()], &self, txs, None);
        batch.needs_unlock = false;
        batch
    }

    /// Run transactions against a frozen bank without committing the results
    pub fn simulate_transaction(&self, transaction: Transaction) -> (Result<()>, Vec<String>) {
        assert!(self.is_frozen(), "simulation bank must be frozen");

        let txs = &[transaction];
        let batch = self.prepare_simulation_batch(txs);
        let log_collector = Rc::new(LogCollector::default());
        let (
            _loaded_accounts,
            executed,
            _retryable_transactions,
            _transaction_count,
            _signature_count,
        ) = self.load_and_execute_transactions(
            &batch,
            MAX_PROCESSING_AGE,
            Some(log_collector.clone()),
        );
        let transaction_result = executed[0].0.clone().map(|_| ());
        let log_messages = Rc::try_unwrap(log_collector).unwrap_or_default().into();
        (transaction_result, log_messages)
    }

    pub fn unlock_accounts(&self, batch: &mut TransactionBatch) {
        if batch.needs_unlock {
            batch.needs_unlock = false;
            self.rc.accounts.unlock_accounts(
                batch.transactions(),
                batch.iteration_order(),
                batch.lock_results(),
            )
        }
    }

    pub fn remove_unrooted_slot(&self, slot: Slot) {
        self.rc.accounts.accounts_db.remove_unrooted_slot(slot)
    }

    fn load_accounts(
        &self,
        txs: &[Transaction],
        iteration_order: Option<&[usize]>,
        results: Vec<TransactionProcessResult>,
        error_counters: &mut ErrorCounters,
    ) -> Vec<(Result<TransactionLoadResult>, Option<HashAgeKind>)> {
        self.rc.accounts.load_accounts(
            &self.ancestors,
            txs,
            iteration_order,
            results,
            &self.blockhash_queue.read().unwrap(),
            error_counters,
            &self.rent_collector,
        )
    }
    fn check_age(
        &self,
        txs: &[Transaction],
        iteration_order: Option<&[usize]>,
        lock_results: Vec<Result<()>>,
        max_age: usize,
        error_counters: &mut ErrorCounters,
    ) -> Vec<TransactionProcessResult> {
        let hash_queue = self.blockhash_queue.read().unwrap();
        OrderedIterator::new(txs, iteration_order)
            .zip(lock_results.into_iter())
            .map(|(tx, lock_res)| match lock_res {
                Ok(()) => {
                    let message = tx.message();
                    let hash_age = hash_queue.check_hash_age(&message.recent_blockhash, max_age);
                    if hash_age == Some(true) {
                        (Ok(()), Some(HashAgeKind::Extant))
                    } else if let Some((pubkey, acc)) = self.check_tx_durable_nonce(&tx) {
                        (Ok(()), Some(HashAgeKind::DurableNonce(pubkey, acc)))
                    } else if hash_age == Some(false) {
                        error_counters.blockhash_too_old += 1;
                        (Err(TransactionError::BlockhashNotFound), None)
                    } else {
                        error_counters.blockhash_not_found += 1;
                        (Err(TransactionError::BlockhashNotFound), None)
                    }
                }
                Err(e) => (Err(e), None),
            })
            .collect()
    }
    fn check_signatures(
        &self,
        txs: &[Transaction],
        iteration_order: Option<&[usize]>,
        lock_results: Vec<TransactionProcessResult>,
        error_counters: &mut ErrorCounters,
    ) -> Vec<TransactionProcessResult> {
        let rcache = self.src.status_cache.read().unwrap();
        OrderedIterator::new(txs, iteration_order)
            .zip(lock_results.into_iter())
            .map(|(tx, lock_res)| {
                if tx.signatures.is_empty() {
                    return lock_res;
                }
                {
                    let (lock_res, hash_age_kind) = &lock_res;
                    if lock_res.is_ok()
                        && rcache
                            .get_signature_status(
                                &tx.signatures[0],
                                &tx.message().recent_blockhash,
                                &self.ancestors,
                            )
                            .is_some()
                    {
                        error_counters.duplicate_signature += 1;
                        return (
                            Err(TransactionError::DuplicateSignature),
                            hash_age_kind.clone(),
                        );
                    }
                }
                lock_res
            })
            .collect()
    }
    fn filter_by_vote_transactions(
        &self,
        txs: &[Transaction],
        iteration_order: Option<&[usize]>,
        lock_results: Vec<TransactionProcessResult>,
        error_counters: &mut ErrorCounters,
    ) -> Vec<TransactionProcessResult> {
        OrderedIterator::new(txs, iteration_order)
            .zip(lock_results.into_iter())
            .map(|(tx, lock_res)| {
                if lock_res.0.is_ok() {
                    if tx.message.instructions.len() == 1 {
                        let instruction = &tx.message.instructions[0];
                        let program_pubkey =
                            tx.message.account_keys[instruction.program_id_index as usize];
                        if program_pubkey == solana_vote_program::id() {
                            if let Ok(vote_instruction) =
                                limited_deserialize::<VoteInstruction>(&instruction.data)
                            {
                                match vote_instruction {
                                    VoteInstruction::Vote(_)
                                    | VoteInstruction::VoteSwitch(_, _) => {
                                        return lock_res;
                                    }
                                    _ => {}
                                }
                            }
                        }
                    }

                    error_counters.not_allowed_during_cluster_maintenance += 1;
                    return (Err(TransactionError::ClusterMaintenance), lock_res.1);
                }
                lock_res
            })
            .collect()
    }

    pub fn check_hash_age(&self, hash: &Hash, max_age: usize) -> Option<bool> {
        self.blockhash_queue
            .read()
            .unwrap()
            .check_hash_age(hash, max_age)
    }

    pub fn check_tx_durable_nonce(&self, tx: &Transaction) -> Option<(Pubkey, Account)> {
        nonce_utils::transaction_uses_durable_nonce(&tx)
            .and_then(|nonce_ix| nonce_utils::get_nonce_pubkey_from_instruction(&nonce_ix, &tx))
            .and_then(|nonce_pubkey| {
                self.get_account(&nonce_pubkey)
                    .map(|acc| (*nonce_pubkey, acc))
            })
            .filter(|(_pubkey, nonce_account)| {
                nonce_utils::verify_nonce_account(nonce_account, &tx.message().recent_blockhash)
            })
    }

    // Determine if the bank is currently in an upgrade epoch, where only votes are permitted
    fn upgrade_epoch(&self) -> bool {
        match self.operating_mode() {
            #[cfg(test)]
            OperatingMode::Development => self.epoch == 0xdead, // Value assumed by `test_upgrade_epoch()`
            #[cfg(not(test))]
            OperatingMode::Development => false,
            OperatingMode::Preview => false,
            OperatingMode::Stable => self.epoch == 61,
        }
    }

    pub fn check_transactions(
        &self,
        txs: &[Transaction],
        iteration_order: Option<&[usize]>,
        lock_results: &[Result<()>],
        max_age: usize,
        mut error_counters: &mut ErrorCounters,
    ) -> Vec<TransactionProcessResult> {
        let age_results = self.check_age(
            txs,
            iteration_order,
            lock_results.to_vec(),
            max_age,
            &mut error_counters,
        );
        let sigcheck_results =
            self.check_signatures(txs, iteration_order, age_results, &mut error_counters);
        if self.upgrade_epoch() {
            // Reject all non-vote transactions
            self.filter_by_vote_transactions(
                txs,
                iteration_order,
                sigcheck_results,
                &mut error_counters,
            )
        } else {
            sigcheck_results
        }
    }

    pub fn collect_balances(&self, batch: &TransactionBatch) -> TransactionBalances {
        let mut balances: TransactionBalances = vec![];
        for transaction in OrderedIterator::new(batch.transactions(), batch.iteration_order()) {
            let mut transaction_balances: Vec<u64> = vec![];
            for account_key in transaction.message.account_keys.iter() {
                transaction_balances.push(self.get_balance(account_key));
            }
            balances.push(transaction_balances);
        }
        balances
    }

    #[allow(clippy::cognitive_complexity)]
    fn update_error_counters(error_counters: &ErrorCounters) {
        if 0 != error_counters.total {
            inc_new_counter_error!(
                "bank-process_transactions-error_count",
                error_counters.total
            );
        }
        if 0 != error_counters.account_not_found {
            inc_new_counter_error!(
                "bank-process_transactions-account_not_found",
                error_counters.account_not_found
            );
        }
        if 0 != error_counters.account_in_use {
            inc_new_counter_error!(
                "bank-process_transactions-account_in_use",
                error_counters.account_in_use
            );
        }
        if 0 != error_counters.account_loaded_twice {
            inc_new_counter_error!(
                "bank-process_transactions-account_loaded_twice",
                error_counters.account_loaded_twice
            );
        }
        if 0 != error_counters.blockhash_not_found {
            inc_new_counter_error!(
                "bank-process_transactions-error-blockhash_not_found",
                error_counters.blockhash_not_found
            );
        }
        if 0 != error_counters.blockhash_too_old {
            inc_new_counter_error!(
                "bank-process_transactions-error-blockhash_too_old",
                error_counters.blockhash_too_old
            );
        }
        if 0 != error_counters.invalid_account_index {
            inc_new_counter_error!(
                "bank-process_transactions-error-invalid_account_index",
                error_counters.invalid_account_index
            );
        }
        if 0 != error_counters.invalid_account_for_fee {
            inc_new_counter_error!(
                "bank-process_transactions-error-invalid_account_for_fee",
                error_counters.invalid_account_for_fee
            );
        }
        if 0 != error_counters.insufficient_funds {
            inc_new_counter_error!(
                "bank-process_transactions-error-insufficient_funds",
                error_counters.insufficient_funds
            );
        }
        if 0 != error_counters.instruction_error {
            inc_new_counter_error!(
                "bank-process_transactions-error-instruction_error",
                error_counters.instruction_error
            );
        }
        if 0 != error_counters.duplicate_signature {
            inc_new_counter_error!(
                "bank-process_transactions-error-duplicate_signature",
                error_counters.duplicate_signature
            );
        }
        if 0 != error_counters.not_allowed_during_cluster_maintenance {
            inc_new_counter_error!(
                "bank-process_transactions-error-cluster-maintenance",
                error_counters.not_allowed_during_cluster_maintenance
            );
        }
    }

    /// Converts Accounts into RefCell<Account>, this involves moving
    /// ownership by draining the source
    fn accounts_to_refcells(
        accounts: &mut TransactionAccounts,
        loaders: &mut TransactionLoaders,
    ) -> (TransactionAccountRefCells, TransactionLoaderRefCells) {
        let account_refcells: Vec<_> = accounts
            .drain(..)
            .map(|account| Rc::new(RefCell::new(account)))
            .collect();
        let loader_refcells: Vec<Vec<_>> = loaders
            .iter_mut()
            .map(|v| {
                v.drain(..)
                    .map(|(pubkey, account)| (pubkey, RefCell::new(account)))
                    .collect()
            })
            .collect();
        (account_refcells, loader_refcells)
    }

    /// Converts back from RefCell<Account> to Account, this involves moving
    /// ownership by draining the sources
    fn refcells_to_accounts(
        accounts: &mut TransactionAccounts,
        loaders: &mut TransactionLoaders,
        mut account_refcells: TransactionAccountRefCells,
        loader_refcells: TransactionLoaderRefCells,
    ) {
        account_refcells.drain(..).for_each(|account_refcell| {
            accounts.push(Rc::try_unwrap(account_refcell).unwrap().into_inner())
        });
        loaders
            .iter_mut()
            .zip(loader_refcells)
            .for_each(|(ls, mut lrcs)| {
                lrcs.drain(..)
                    .for_each(|(pubkey, lrc)| ls.push((pubkey, lrc.into_inner())))
            });
    }

    #[allow(clippy::type_complexity)]
    pub fn load_and_execute_transactions(
        &self,
        batch: &TransactionBatch,
        max_age: usize,
        log_collector: Option<Rc<LogCollector>>,
    ) -> (
        Vec<(Result<TransactionLoadResult>, Option<HashAgeKind>)>,
        Vec<TransactionProcessResult>,
        Vec<usize>,
        u64,
        u64,
    ) {
        let txs = batch.transactions();
        debug!("processing transactions: {}", txs.len());
        inc_new_counter_info!("bank-process_transactions", txs.len());
        let mut error_counters = ErrorCounters::default();
        let mut load_time = Measure::start("accounts_load");

        let retryable_txs: Vec<_> =
            OrderedIterator::new(batch.lock_results(), batch.iteration_order())
                .enumerate()
                .filter_map(|(index, res)| match res {
                    Err(TransactionError::AccountInUse) => {
                        error_counters.account_in_use += 1;
                        Some(index)
                    }
                    Ok(_) => None,
                    Err(_) => None,
                })
                .collect();

        let sig_results = self.check_transactions(
            txs,
            batch.iteration_order(),
            batch.lock_results(),
            max_age,
            &mut error_counters,
        );
        let mut loaded_accounts = self.load_accounts(
            txs,
            batch.iteration_order(),
            sig_results,
            &mut error_counters,
        );
        load_time.stop();

        let mut execution_time = Measure::start("execution_time");
        let mut signature_count: u64 = 0;
        let executed: Vec<TransactionProcessResult> = loaded_accounts
            .iter_mut()
            .zip(OrderedIterator::new(txs, batch.iteration_order()))
            .map(|(accs, tx)| match accs {
                (Err(e), hash_age_kind) => (Err(e.clone()), hash_age_kind.clone()),
                (Ok((accounts, loaders, _rents)), hash_age_kind) => {
                    signature_count += u64::from(tx.message().header.num_required_signatures);

                    let (account_refcells, loader_refcells) =
                        Self::accounts_to_refcells(accounts, loaders);

                    let process_result = self.message_processor.process_message(
                        tx.message(),
                        &loader_refcells,
                        &account_refcells,
                        &self.rent_collector,
                        log_collector.clone(),
                    );

                    Self::refcells_to_accounts(
                        accounts,
                        loaders,
                        account_refcells,
                        loader_refcells,
                    );

                    if let Err(TransactionError::InstructionError(_, _)) = &process_result {
                        error_counters.instruction_error += 1;
                    }
                    (process_result, hash_age_kind.clone())
                }
            })
            .collect();

        execution_time.stop();

        debug!(
            "load: {}us execute: {}us txs_len={}",
            load_time.as_us(),
            execution_time.as_us(),
            txs.len(),
        );

        let mut tx_count: u64 = 0;
        let err_count = &mut error_counters.total;
        for ((r, _hash_age_kind), tx) in executed.iter().zip(txs.iter()) {
            if r.is_ok() {
                tx_count += 1;
            } else {
                if *err_count == 0 {
                    debug!("tx error: {:?} {:?}", r, tx);
                }
                *err_count += 1;
            }
        }
        if *err_count > 0 {
            debug!(
                "{} errors of {} txs",
                *err_count,
                *err_count as u64 + tx_count
            );
        }
        Self::update_error_counters(&error_counters);
        (
            loaded_accounts,
            executed,
            retryable_txs,
            tx_count,
            signature_count,
        )
    }

    fn filter_program_errors_and_collect_fee(
        &self,
        txs: &[Transaction],
        iteration_order: Option<&[usize]>,
        executed: &[TransactionProcessResult],
    ) -> Vec<Result<()>> {
        let hash_queue = self.blockhash_queue.read().unwrap();
        let mut fees = 0;
        let results = OrderedIterator::new(txs, iteration_order)
            .zip(executed.iter())
            .map(|(tx, (res, hash_age_kind))| {
                let (fee_calculator, is_durable_nonce) = match hash_age_kind {
                    Some(HashAgeKind::DurableNonce(_, account)) => {
                        (nonce_utils::fee_calculator_of(account), true)
                    }
                    _ => (
                        hash_queue
                            .get_fee_calculator(&tx.message().recent_blockhash)
                            .cloned(),
                        false,
                    ),
                };
                let fee_calculator = fee_calculator.ok_or(TransactionError::BlockhashNotFound)?;

                let fee = fee_calculator.calculate_fee(tx.message());

                let message = tx.message();
                match *res {
                    Err(TransactionError::InstructionError(_, _)) => {
                        // credit the transaction fee even in case of InstructionError
                        // necessary to withdraw from account[0] here because previous
                        // work of doing so (in accounts.load()) is ignored by store_account()
                        //
                        // ...except nonce accounts, which will have their post-load,
                        // pre-execute account state stored
                        if !is_durable_nonce {
                            self.withdraw(&message.account_keys[0], fee)?;
                        }
                        fees += fee;
                        Ok(())
                    }
                    Ok(()) => {
                        fees += fee;
                        Ok(())
                    }
                    _ => res.clone(),
                }
            })
            .collect();

        self.collector_fees.fetch_add(fees, Ordering::Relaxed);
        results
    }

    pub fn commit_transactions(
        &self,
        txs: &[Transaction],
        iteration_order: Option<&[usize]>,
        loaded_accounts: &mut [(Result<TransactionLoadResult>, Option<HashAgeKind>)],
        executed: &[TransactionProcessResult],
        tx_count: u64,
        signature_count: u64,
    ) -> TransactionResults {
        assert!(
            !self.is_frozen(),
            "commit_transactions() working on a frozen bank!"
        );

        self.increment_transaction_count(tx_count);
        self.increment_signature_count(signature_count);

        inc_new_counter_info!("bank-process_transactions-txs", tx_count as usize);
        inc_new_counter_info!("bank-process_transactions-sigs", signature_count as usize);

        if executed
            .iter()
            .any(|(res, _hash_age_kind)| Self::can_commit(res))
        {
            self.is_delta.store(true, Ordering::Relaxed);
        }

        let mut write_time = Measure::start("write_time");
        self.rc.accounts.store_accounts(
            self.slot(),
            txs,
            iteration_order,
            executed,
            loaded_accounts,
            &self.rent_collector,
            &self.last_blockhash_with_fee_calculator(),
            self.fix_recent_blockhashes_sysvar_delay(),
        );
        self.collect_rent(executed, loaded_accounts);

        self.update_cached_accounts(txs, iteration_order, executed, loaded_accounts);

        // once committed there is no way to unroll
        write_time.stop();
        debug!("store: {}us txs_len={}", write_time.as_us(), txs.len(),);
        self.update_transaction_statuses(txs, iteration_order, &executed);
        let fee_collection_results =
            self.filter_program_errors_and_collect_fee(txs, iteration_order, executed);
        TransactionResults {
            fee_collection_results,
            processing_results: executed.to_vec(),
        }
    }

    fn distribute_rent_to_validators(
        &self,
        vote_account_hashmap: &HashMap<Pubkey, (u64, Account)>,
        rent_to_be_distributed: u64,
    ) {
        let mut total_staked = 0;
        let mut rent_distributed_in_initial_round = 0;

        // Collect the stake associated with each validator.
        // Note that a validator may be present in this vector multiple times if it happens to have
        // more than one staked vote account somehow
        let mut validator_stakes = vote_account_hashmap
            .iter()
            .filter_map(|(_vote_pubkey, (staked, account))| {
                if *staked == 0 {
                    None
                } else {
                    total_staked += *staked;
                    VoteState::deserialize(&account.data)
                        .ok()
                        .map(|vote_state| (vote_state.node_pubkey, *staked))
                }
            })
            .collect::<Vec<(Pubkey, u64)>>();

        // Sort first by stake and then by validator identity pubkey for determinism
        validator_stakes.sort_by(|(pubkey1, staked1), (pubkey2, staked2)| {
            match staked2.cmp(staked1) {
                std::cmp::Ordering::Equal => pubkey2.cmp(pubkey1),
                other => other,
            }
        });

        let validator_rent_shares = validator_stakes
            .into_iter()
            .map(|(pubkey, staked)| {
                let rent_share =
                    (((staked * rent_to_be_distributed) as f64) / (total_staked as f64)) as u64;
                rent_distributed_in_initial_round += rent_share;
                (pubkey, rent_share)
            })
            .collect::<Vec<(Pubkey, u64)>>();

        // Leftover lamports after fraction calculation, will be paid to validators starting from highest stake
        // holder
        let mut leftover_lamports = rent_to_be_distributed - rent_distributed_in_initial_round;

        validator_rent_shares
            .into_iter()
            .for_each(|(pubkey, rent_share)| {
                let rent_to_be_paid = if leftover_lamports > 0 {
                    leftover_lamports -= 1;
                    rent_share + 1
                } else {
                    rent_share
                };
                let mut account = self.get_account(&pubkey).unwrap_or_default();
                account.lamports += rent_to_be_paid;
                self.store_account(&pubkey, &account);
            });
    }

    fn distribute_rent(&self) {
        let total_rent_collected = self.collected_rent.load(Ordering::Relaxed);

        let (burned_portion, rent_to_be_distributed) = self
            .rent_collector
            .rent
            .calculate_burn(total_rent_collected);

        self.capitalization
            .fetch_sub(burned_portion, Ordering::Relaxed);

        if rent_to_be_distributed == 0 {
            return;
        }

        self.distribute_rent_to_validators(&self.vote_accounts(), rent_to_be_distributed);
    }

    fn collect_rent(
        &self,
        res: &[TransactionProcessResult],
        loaded_accounts: &[(Result<TransactionLoadResult>, Option<HashAgeKind>)],
    ) {
        let mut collected_rent: u64 = 0;
        for (i, (raccs, _hash_age_kind)) in loaded_accounts.iter().enumerate() {
            let (res, _hash_age_kind) = &res[i];
            if res.is_err() || raccs.is_err() {
                continue;
            }

            let acc = raccs.as_ref().unwrap();

            collected_rent += acc.2;
        }

        self.collected_rent
            .fetch_add(collected_rent, Ordering::Relaxed);
    }

    fn run_incinerator(&self) {
        if let Some((account, _)) = self.get_account_modified_since_parent(&incinerator::id()) {
            self.capitalization
                .fetch_sub(account.lamports, Ordering::Relaxed);
            self.store_account(&incinerator::id(), &Account::default());
        }
    }

    fn collect_rent_eagerly(&self) {
        if !self.enable_eager_rent_collection() {
            return;
        }

        let mut measure = Measure::start("collect_rent_eagerly-ms");
        for partition in self.rent_collection_partitions() {
            self.collect_rent_in_partition(partition);
        }
        measure.stop();
        inc_new_counter_info!("collect_rent_eagerly-ms", measure.as_ms() as usize);
    }

    fn enable_eager_rent_collection(&self) -> bool {
        if self.lazy_rent_collection.load(Ordering::Relaxed) {
            return false;
        }

        true
    }

    fn rent_collection_partitions(&self) -> Vec<Partition> {
        if !self.use_fixed_collection_cycle() {
            // This mode is for production/development/testing.
            // In this mode, we iterate over the whole pubkey value range for each epochs
            // including warm-up epochs.
            // The only exception is the situation where normal epochs are relatively short
            // (currently less than 2 day). In that case, we arrange a single collection
            // cycle to be multiple of epochs so that a cycle could be greater than the 2 day.
            self.variable_cycle_partitions()
        } else {
            // This mode is mainly for benchmarking only.
            // In this mode, we always iterate over the whole pubkey value range with
            // <slot_count_in_two_day> slots as a collection cycle, regardless warm-up or
            // alignment between collection cycles and epochs.
            // Thus, we can simulate stable processing load of eager rent collection,
            // strictly proportional to the number of pubkeys since genesis.
            self.fixed_cycle_partitions()
        }
    }

    fn collect_rent_in_partition(&self, partition: Partition) {
        let subrange = Self::pubkey_range_from_partition(partition);

        let accounts = self
            .rc
            .accounts
            .load_to_collect_rent_eagerly(&self.ancestors, subrange);
        let account_count = accounts.len();

        // parallelize?
        let mut rent = 0;
        for (pubkey, mut account) in accounts {
            rent += self.rent_collector.update(&pubkey, &mut account);
            // Store all of them unconditionally to purge old AppendVec,
            // even if collected rent is 0 (= not updated).
            self.store_account(&pubkey, &account);
        }
        self.collected_rent.fetch_add(rent, Ordering::Relaxed);

        datapoint_info!("collect_rent_eagerly", ("accounts", account_count, i64));
    }

    // Mostly, the pair (start_index & end_index) is equivalent to this range:
    // start_index..=end_index. But it has some exceptional cases, including
    // this important and valid one:
    //   0..=0: the first partition in the new epoch when crossing epochs
    fn pubkey_range_from_partition(
        (start_index, end_index, partition_count): Partition,
    ) -> RangeInclusive<Pubkey> {
        assert!(start_index <= end_index);
        assert!(start_index < partition_count);
        assert!(end_index < partition_count);
        assert!(0 < partition_count);

        type Prefix = u64;
        const PREFIX_SIZE: usize = mem::size_of::<Prefix>();
        const PREFIX_MAX: Prefix = Prefix::max_value();

        let mut start_pubkey = [0x00u8; 32];
        let mut end_pubkey = [0xffu8; 32];

        if partition_count == 1 {
            assert_eq!(start_index, 0);
            assert_eq!(end_index, 0);
            return Pubkey::new_from_array(start_pubkey)..=Pubkey::new_from_array(end_pubkey);
        }

        // not-overflowing way of `(Prefix::max_value() + 1) / partition_count`
        let partition_width = (PREFIX_MAX - partition_count + 1) / partition_count + 1;
        let mut start_key_prefix = if start_index == 0 && end_index == 0 {
            0
        } else {
            (start_index + 1) * partition_width
        };

        let mut end_key_prefix = if end_index + 1 == partition_count {
            PREFIX_MAX
        } else {
            (end_index + 1) * partition_width - 1
        };

        if start_index != 0 && start_index == end_index {
            // n..=n (n != 0): a noop pair across epochs without a gap under
            // multi_epoch_cycle, just nullify it.
            if end_key_prefix == PREFIX_MAX {
                start_key_prefix = end_key_prefix;
                start_pubkey = end_pubkey;
            } else {
                end_key_prefix = start_key_prefix;
                end_pubkey = start_pubkey;
            }
        }

        start_pubkey[0..PREFIX_SIZE].copy_from_slice(&start_key_prefix.to_be_bytes());
        end_pubkey[0..PREFIX_SIZE].copy_from_slice(&end_key_prefix.to_be_bytes());
        trace!(
            "pubkey_range_from_partition: ({}-{})/{} [{}]: {}-{}",
            start_index,
            end_index,
            partition_count,
            (end_key_prefix - start_key_prefix),
            start_pubkey.iter().map(|x| format!("{:02x}", x)).join(""),
            end_pubkey.iter().map(|x| format!("{:02x}", x)).join(""),
        );
        // should be an inclusive range (a closed interval) like this:
        // [0xgg00-0xhhff], [0xii00-0xjjff], ... (where 0xii00 == 0xhhff + 1)
        Pubkey::new_from_array(start_pubkey)..=Pubkey::new_from_array(end_pubkey)
    }

    fn fixed_cycle_partitions(&self) -> Vec<Partition> {
        let slot_count_in_two_day = self.slot_count_in_two_day();

        let parent_cycle = self.parent_slot() / slot_count_in_two_day;
        let current_cycle = self.slot() / slot_count_in_two_day;
        let mut parent_cycle_index = self.parent_slot() % slot_count_in_two_day;
        let current_cycle_index = self.slot() % slot_count_in_two_day;
        let mut partitions = vec![];
        if parent_cycle < current_cycle {
            if current_cycle_index > 0 {
                // generate and push gapped partitions because some slots are skipped
                let parent_last_cycle_index = slot_count_in_two_day - 1;

                // ... for parent cycle
                partitions.push((
                    parent_cycle_index,
                    parent_last_cycle_index,
                    slot_count_in_two_day,
                ));

                // ... for current cycle
                partitions.push((0, 0, slot_count_in_two_day));
            }
            parent_cycle_index = 0;
        }

        partitions.push((
            parent_cycle_index,
            current_cycle_index,
            slot_count_in_two_day,
        ));

        partitions
    }

    fn variable_cycle_partitions(&self) -> Vec<Partition> {
        let (current_epoch, current_slot_index) = self.get_epoch_and_slot_index(self.slot());
        let (parent_epoch, mut parent_slot_index) =
            self.get_epoch_and_slot_index(self.parent_slot());

        let should_enable = match self.operating_mode() {
            OperatingMode::Development => true,
            OperatingMode::Preview => current_epoch >= Epoch::max_value(),
            OperatingMode::Stable => {
                #[cfg(not(test))]
                let should_enable = current_epoch >= Epoch::max_value();

                // needed for test_rent_eager_across_epoch_with_gap_under_multi_epoch_cycle,
                // which depends on OperatingMode::Stable
                #[cfg(test)]
                let should_enable = true;

                should_enable
            }
        };

        let mut partitions = vec![];
        if parent_epoch < current_epoch {
            // this needs to be gated because this potentially can change the behavior
            // (= bank hash) at each start of epochs
            let slot_skipped = if should_enable {
                (self.slot() - self.parent_slot()) > 1
            } else {
                current_slot_index > 0
            };
            if slot_skipped {
                // Generate special partitions because there are skipped slots
                // exactly at the epoch transition.

                let parent_last_slot_index = self.get_slots_in_epoch(parent_epoch) - 1;

                // ... for parent epoch
                partitions.push(self.partition_from_slot_indexes_with_gapped_epochs(
                    parent_slot_index,
                    parent_last_slot_index,
                    parent_epoch,
                ));

                // this needs to be gated because this potentially can change the behavior
                // (= bank hash) at each start of epochs
                if should_enable && current_slot_index > 0 {
                    // ... for current epoch
                    partitions.push(self.partition_from_slot_indexes_with_gapped_epochs(
                        0,
                        0,
                        current_epoch,
                    ));
                }
            }
            parent_slot_index = 0;
        }

        partitions.push(self.partition_from_normal_slot_indexes(
            parent_slot_index,
            current_slot_index,
            current_epoch,
        ));

        partitions
    }

    fn do_partition_from_slot_indexes(
        &self,
        start_slot_index: SlotIndex,
        end_slot_index: SlotIndex,
        epoch: Epoch,
        generated_for_gapped_epochs: bool,
    ) -> Partition {
        let cycle_params = self.determine_collection_cycle_params(epoch);
        let (_, _, in_multi_epoch_cycle, _, _, partition_count) = cycle_params;

        // use common code-path for both very-likely and very-unlikely for the sake of minimized
        // risk of any mis-calculation instead of neligilbe faster computation per slot for the
        // likely case.
        let mut start_partition_index =
            Self::partition_index_from_slot_index(start_slot_index, cycle_params);
        let mut end_partition_index =
            Self::partition_index_from_slot_index(end_slot_index, cycle_params);

        // Adjust partition index for some edge cases
        let is_special_new_epoch = start_slot_index == 0 && end_slot_index != 1;
        let in_middle_of_cycle = start_partition_index > 0;
        if in_multi_epoch_cycle && is_special_new_epoch && in_middle_of_cycle {
            // Adjust slot indexes so that the final partition ranges are continuous!
            // This is neeed because the caller gives us off-by-one indexes when
            // an epoch boundary is crossed.
            // Usually there is no need for this adjustment because cycles are aligned
            // with epochs. But for multi-epoch cycles, adjust the indexes if it
            // happens in the middle of a cycle for both gapped and not-gapped cases:
            //
            // epoch (slot range)|slot idx.*1|raw part. idx.|adj. part. idx.|epoch boundary
            // ------------------+-----------+--------------+---------------+--------------
            // 3 (20..30)        | [7..8]    |   7.. 8      |   7.. 8
            //                   | [8..9]    |   8.. 9      |   8.. 9
            // 4 (30..40)        | [0..0]    |<10>..10      | <9>..10      <--- not gapped
            //                   | [0..1]    |  10..11      |  10..12
            //                   | [1..2]    |  11..12      |  11..12
            //                   | [2..9   *2|  12..19      |  12..19      <-+
            // 5 (40..50)        |  0..0   *2|<20>..<20>    |<19>..<19> *3 <-+- gapped
            //                   |  0..4]    |<20>..24      |<19>..24      <-+
            //                   | [4..5]    |  24..25      |  24..25
            //                   | [5..6]    |  25..26      |  25..26
            //
            // NOTE: <..> means the adjusted slots
            //
            // *1: The range of parent_bank.slot() and current_bank.slot() is firstly
            //     split by the epoch boundaries and then the split ones are given to us.
            //     The original ranges are denoted as [...]
            // *2: These are marked with generated_for_gapped_epochs = true.
            // *3: This becomes no-op partition
            start_partition_index -= 1;
            if generated_for_gapped_epochs {
                assert_eq!(start_slot_index, end_slot_index);
                end_partition_index -= 1;
            }
        }

        (start_partition_index, end_partition_index, partition_count)
    }

    fn partition_from_normal_slot_indexes(
        &self,
        start_slot_index: SlotIndex,
        end_slot_index: SlotIndex,
        epoch: Epoch,
    ) -> Partition {
        self.do_partition_from_slot_indexes(start_slot_index, end_slot_index, epoch, false)
    }

    fn partition_from_slot_indexes_with_gapped_epochs(
        &self,
        start_slot_index: SlotIndex,
        end_slot_index: SlotIndex,
        epoch: Epoch,
    ) -> Partition {
        self.do_partition_from_slot_indexes(start_slot_index, end_slot_index, epoch, true)
    }

    fn determine_collection_cycle_params(&self, epoch: Epoch) -> RentCollectionCycleParams {
        let slot_count_per_epoch = self.get_slots_in_epoch(epoch);

        if !self.use_multi_epoch_collection_cycle(epoch) {
            (
                epoch,
                slot_count_per_epoch,
                false,
                0,
                1,
                slot_count_per_epoch,
            )
        } else {
            let epoch_count_in_cycle = self.slot_count_in_two_day() / slot_count_per_epoch;
            let partition_count = slot_count_per_epoch * epoch_count_in_cycle;

            (
                epoch,
                slot_count_per_epoch,
                true,
                self.first_normal_epoch(),
                epoch_count_in_cycle,
                partition_count,
            )
        }
    }

    fn partition_index_from_slot_index(
        slot_index_in_epoch: SlotIndex,
        (
            epoch,
            slot_count_per_epoch,
            _,
            base_epoch,
            epoch_count_per_cycle,
            _,
        ): RentCollectionCycleParams,
    ) -> PartitionIndex {
        let epoch_offset = epoch - base_epoch;
        let epoch_index_in_cycle = epoch_offset % epoch_count_per_cycle;
        slot_index_in_epoch + epoch_index_in_cycle * slot_count_per_epoch
    }

    // Given short epochs, it's too costly to collect rent eagerly
    // within an epoch, so lower the frequency of it.
    // These logic isn't strictly eager anymore and should only be used
    // for development/performance purpose.
    // Absolutely not under OperationMode::Stable!!!!
    fn use_multi_epoch_collection_cycle(&self, epoch: Epoch) -> bool {
        epoch >= self.first_normal_epoch()
            && self.slot_count_per_normal_epoch() < self.slot_count_in_two_day()
    }

    fn use_fixed_collection_cycle(&self) -> bool {
        self.operating_mode() != OperatingMode::Stable
            && self.slot_count_per_normal_epoch() < self.slot_count_in_two_day()
    }

    // This value is specially chosen to align with slots per epoch in mainnet-beta and testnet
    // Also, assume 500GB account data set as the extreme, then for 2 day (=48 hours) to collect
    // rent eagerly, we'll consume 5.7 MB/s IO bandwidth, bidirectionally.
    fn slot_count_in_two_day(&self) -> SlotCount {
        2 * DEFAULT_TICKS_PER_SECOND * SECONDS_PER_DAY / self.ticks_per_slot
    }

    fn slot_count_per_normal_epoch(&self) -> SlotCount {
        self.get_slots_in_epoch(self.first_normal_epoch())
    }

    pub fn operating_mode(&self) -> OperatingMode {
        // unwrap is safe; self.operating_mode is ensured to be Some() always...
        // we only using Option here for ABI compatibility...
        self.operating_mode.unwrap()
    }

    /// Process a batch of transactions.
    #[must_use]
    pub fn load_execute_and_commit_transactions(
        &self,
        batch: &TransactionBatch,
        max_age: usize,
        collect_balances: bool,
    ) -> (TransactionResults, TransactionBalancesSet) {
        let pre_balances = if collect_balances {
            self.collect_balances(batch)
        } else {
            vec![]
        };
        let (mut loaded_accounts, executed, _, tx_count, signature_count) =
            self.load_and_execute_transactions(batch, max_age, None);

        let results = self.commit_transactions(
            batch.transactions(),
            batch.iteration_order(),
            &mut loaded_accounts,
            &executed,
            tx_count,
            signature_count,
        );
        let post_balances = if collect_balances {
            self.collect_balances(batch)
        } else {
            vec![]
        };
        (
            results,
            TransactionBalancesSet::new(pre_balances, post_balances),
        )
    }

    #[must_use]
    pub fn process_transactions(&self, txs: &[Transaction]) -> Vec<Result<()>> {
        let batch = self.prepare_batch(txs, None);
        self.load_execute_and_commit_transactions(&batch, MAX_PROCESSING_AGE, false)
            .0
            .fee_collection_results
    }

    /// Create, sign, and process a Transaction from `keypair` to `to` of
    /// `n` lamports where `blockhash` is the last Entry ID observed by the client.
    pub fn transfer(&self, n: u64, keypair: &Keypair, to: &Pubkey) -> Result<Signature> {
        let blockhash = self.last_blockhash();
        let tx = system_transaction::transfer(keypair, to, n, blockhash);
        let signature = tx.signatures[0];
        self.process_transaction(&tx).map(|_| signature)
    }

    pub fn read_balance(account: &Account) -> u64 {
        account.lamports
    }
    /// Each program would need to be able to introspect its own state
    /// this is hard-coded to the Budget language
    pub fn get_balance(&self, pubkey: &Pubkey) -> u64 {
        self.get_account(pubkey)
            .map(|x| Self::read_balance(&x))
            .unwrap_or(0)
    }

    /// Compute all the parents of the bank in order
    pub fn parents(&self) -> Vec<Arc<Bank>> {
        let mut parents = vec![];
        let mut bank = self.parent();
        while let Some(parent) = bank {
            parents.push(parent.clone());
            bank = parent.parent();
        }
        parents
    }

    pub fn store_account(&self, pubkey: &Pubkey, account: &Account) {
        self.rc.accounts.store_slow(self.slot(), pubkey, account);

        if Stakes::is_stake(account) {
            self.stakes.write().unwrap().store(pubkey, account);
        }
    }

    pub fn withdraw(&self, pubkey: &Pubkey, lamports: u64) -> Result<()> {
        match self.get_account(pubkey) {
            Some(mut account) => {
                let min_balance = match get_system_account_kind(&account) {
                    Some(SystemAccountKind::Nonce) => self
                        .rent_collector
                        .rent
                        .minimum_balance(nonce::State::size()),
                    _ => 0,
                };
                if lamports + min_balance > account.lamports {
                    return Err(TransactionError::InsufficientFundsForFee);
                }

                account.lamports -= lamports;
                self.store_account(pubkey, &account);

                Ok(())
            }
            None => Err(TransactionError::AccountNotFound),
        }
    }

    pub fn deposit(&self, pubkey: &Pubkey, lamports: u64) {
        let mut account = self.get_account(pubkey).unwrap_or_default();
        self.collected_rent.fetch_add(
            self.rent_collector.update(pubkey, &mut account),
            Ordering::Relaxed,
        );
        account.lamports += lamports;
        self.store_account(pubkey, &account);
    }

    pub fn accounts(&self) -> Arc<Accounts> {
        self.rc.accounts.clone()
    }

    pub fn set_bank_rc(&mut self, bank_rc: BankRc, status_cache_rc: StatusCacheRc) {
        self.rc = bank_rc;
        self.src = status_cache_rc;
    }

    pub fn finish_init(&mut self) {
        let builtin_programs = get_builtin_programs(self.operating_mode(), self.epoch);
        for program in builtin_programs.iter() {
            self.add_builtin_program(&program.name, program.id, program.process_instruction);
        }
    }

    pub fn set_parent(&mut self, parent: &Arc<Bank>) {
        self.rc.parent = RwLock::new(Some(parent.clone()));
    }

    pub fn set_inflation(&self, inflation: Inflation) {
        *self.inflation.write().unwrap() = inflation;
    }

    pub fn hard_forks(&self) -> Arc<RwLock<HardForks>> {
        self.hard_forks.clone()
    }

    pub fn set_entered_epoch_callback(&self, entered_epoch_callback: EnteredEpochCallback) {
        *self.entered_epoch_callback.write().unwrap() = Some(entered_epoch_callback);
    }

    pub fn get_account(&self, pubkey: &Pubkey) -> Option<Account> {
        self.get_account_modified_slot(pubkey)
            .map(|(acc, _slot)| acc)
    }

    pub fn get_account_modified_slot(&self, pubkey: &Pubkey) -> Option<(Account, Slot)> {
        self.rc.accounts.load_slow(&self.ancestors, pubkey)
    }

    // Exclude self to really fetch the parent Bank's account hash and data.
    //
    // Being idempotent is needed to make the lazy initialization possible,
    // especially for update_slot_hashes at the moment, which can be called
    // multiple times with the same parent_slot in the case of forking.
    //
    // Generally, all of sysvar update granularity should be slot boundaries.
    fn get_sysvar_account(&self, pubkey: &Pubkey) -> Option<Account> {
        let mut ancestors = self.ancestors.clone();
        ancestors.remove(&self.slot());
        self.rc
            .accounts
            .load_slow(&ancestors, pubkey)
            .map(|(acc, _slot)| acc)
    }

    pub fn get_program_accounts(&self, program_id: Option<&Pubkey>) -> Vec<(Pubkey, Account)> {
        self.rc
            .accounts
            .load_by_program(&self.ancestors, program_id)
    }

    pub fn get_program_accounts_modified_since_parent(
        &self,
        program_id: &Pubkey,
    ) -> Vec<(Pubkey, Account)> {
        self.rc
            .accounts
            .load_by_program_slot(self.slot(), Some(program_id))
    }

    pub fn get_all_accounts_modified_since_parent(&self) -> Vec<(Pubkey, Account)> {
        self.rc.accounts.load_by_program_slot(self.slot(), None)
    }

    pub fn get_account_modified_since_parent(&self, pubkey: &Pubkey) -> Option<(Account, Slot)> {
        let just_self: Ancestors = vec![(self.slot(), 0)].into_iter().collect();
        if let Some((account, slot)) = self.rc.accounts.load_slow(&just_self, pubkey) {
            if slot == self.slot() {
                return Some((account, slot));
            }
        }
        None
    }

    pub fn get_largest_accounts(
        &self,
        num: usize,
        filter_by_address: &HashSet<Pubkey>,
        filter: AccountAddressFilter,
    ) -> Vec<(Pubkey, u64)> {
        self.rc
            .accounts
            .load_largest_accounts(&self.ancestors, num, filter_by_address, filter)
    }

    pub fn transaction_count(&self) -> u64 {
        self.transaction_count.load(Ordering::Relaxed)
    }

    fn increment_transaction_count(&self, tx_count: u64) {
        self.transaction_count
            .fetch_add(tx_count, Ordering::Relaxed);
    }

    pub fn signature_count(&self) -> u64 {
        self.signature_count.load(Ordering::Relaxed)
    }

    fn increment_signature_count(&self, signature_count: u64) {
        self.signature_count
            .fetch_add(signature_count, Ordering::Relaxed);
    }

    pub fn get_signature_status_processed_since_parent(
        &self,
        signature: &Signature,
    ) -> Option<Result<()>> {
        if let Some((slot, status)) = self.get_signature_status_slot(signature) {
            if slot <= self.slot() {
                return Some(status);
            }
        }
        None
    }

    pub fn get_signature_status_slot(&self, signature: &Signature) -> Option<(Slot, Result<()>)> {
        let rcache = self.src.status_cache.read().unwrap();
        rcache.get_signature_slot(signature, &self.ancestors)
    }

    pub fn get_signature_status(&self, signature: &Signature) -> Option<Result<()>> {
        self.get_signature_status_slot(signature).map(|v| v.1)
    }

    pub fn has_signature(&self, signature: &Signature) -> bool {
        self.get_signature_status_slot(signature).is_some()
    }

    /// Hash the `accounts` HashMap. This represents a validator's interpretation
    ///  of the delta of the ledger since the last vote and up to now
    fn hash_internal_state(&self) -> Hash {
        // If there are no accounts, return the hash of the previous state and the latest blockhash
        let accounts_delta_hash = self.rc.accounts.bank_hash_info_at(self.slot());
        let mut signature_count_buf = [0u8; 8];
        LittleEndian::write_u64(&mut signature_count_buf[..], self.signature_count() as u64);

        let mut hash = hashv(&[
            self.parent_hash.as_ref(),
            accounts_delta_hash.hash.as_ref(),
            &signature_count_buf,
            self.last_blockhash().as_ref(),
        ]);

        if let Some(buf) = self
            .hard_forks
            .read()
            .unwrap()
            .get_hash_data(self.slot(), self.parent_slot())
        {
            info!("hard fork at bank {}", self.slot());
            hash = extend_and_hash(&hash, &buf)
        }

        info!(
            "bank frozen: {} hash: {} accounts_delta: {} signature_count: {} last_blockhash: {} capitalization: {}",
            self.slot(),
            hash,
            accounts_delta_hash.hash,
            self.signature_count(),
            self.last_blockhash(),
            self.capitalization(),
        );

        info!(
            "accounts hash slot: {} stats: {:?}",
            self.slot(),
            accounts_delta_hash.stats,
        );
        hash
    }

    /// Recalculate the hash_internal_state from the account stores. Would be used to verify a
    /// snapshot.
    #[must_use]
    fn verify_bank_hash(&self) -> bool {
        self.rc
            .accounts
            .verify_bank_hash(self.slot(), &self.ancestors)
    }

    pub fn get_snapshot_storages(&self) -> SnapshotStorages {
        self.rc
            .get_snapshot_storages(self.slot())
            .into_iter()
            .collect()
    }

    #[must_use]
    fn verify_hash(&self) -> bool {
        assert!(self.is_frozen());
        let calculated_hash = self.hash_internal_state();
        let expected_hash = self.hash();

        if calculated_hash == expected_hash {
            true
        } else {
            warn!(
                "verify failed: slot: {}, {} (calculated) != {} (expected)",
                self.slot(),
                calculated_hash,
                expected_hash
            );
            false
        }
    }

    pub fn calculate_capitalization(&self) -> u64 {
        self.get_program_accounts(None)
            .into_iter()
            .map(|(_pubkey, account)| {
                let is_specially_retained = solana_sdk::native_loader::check_id(&account.owner)
                    || solana_sdk::sysvar::check_id(&account.owner);

                if is_specially_retained {
                    // specially retained accounts are ensured to exist by
                    // always having a balance of 1 lamports, which is
                    // outside the capitalization calculation.
                    account.lamports - 1
                } else {
                    account.lamports
                }
            })
            .sum()
    }

    /// Forcibly overwrites current capitalization by actually recalculating accounts' balances.
    /// This should only be used for developing purposes.
    pub fn set_capitalization(&self) -> u64 {
        let old = self.capitalization();
        self.capitalization
            .store(self.calculate_capitalization(), Ordering::Relaxed);
        old
    }

    pub fn get_accounts_hash(&self) -> Hash {
        self.rc.accounts.accounts_db.get_accounts_hash(self.slot)
    }

    pub fn update_accounts_hash(&self) -> Hash {
        self.rc
            .accounts
            .accounts_db
            .update_accounts_hash(self.slot(), &self.ancestors)
    }

    /// A snapshot bank should be purged of 0 lamport accounts which are not part of the hash
    /// calculation and could shield other real accounts.
    pub fn verify_snapshot_bank(&self) -> bool {
        self.clean_accounts();
        self.shrink_all_slots();
        // Order and short-circuiting is significant; verify_hash requires a valid bank hash
        self.verify_bank_hash() && self.verify_hash()
    }

    /// Return the number of hashes per tick
    pub fn hashes_per_tick(&self) -> &Option<u64> {
        &self.hashes_per_tick
    }

    /// Return the number of ticks per slot
    pub fn ticks_per_slot(&self) -> u64 {
        self.ticks_per_slot
    }

    /// Return the number of slots per year
    pub fn slots_per_year(&self) -> f64 {
        self.slots_per_year
    }

    /// Return the number of ticks since genesis.
    pub fn tick_height(&self) -> u64 {
        self.tick_height.load(Ordering::Relaxed)
    }

    /// Return the inflation parameters of the Bank
    pub fn inflation(&self) -> Inflation {
        *self.inflation.read().unwrap()
    }

    /// Return the total capitalization of the Bank
    pub fn capitalization(&self) -> u64 {
        self.capitalization.load(Ordering::Relaxed)
    }

    /// Return this bank's max_tick_height
    pub fn max_tick_height(&self) -> u64 {
        self.max_tick_height
    }

    /// Return the block_height of this bank
    pub fn block_height(&self) -> u64 {
        self.block_height
    }

    /// Return the number of slots per epoch for the given epoch
    pub fn get_slots_in_epoch(&self, epoch: Epoch) -> u64 {
        self.epoch_schedule.get_slots_in_epoch(epoch)
    }

    /// returns the epoch for which this bank's leader_schedule_slot_offset and slot would
    ///  need to cache leader_schedule
    pub fn get_leader_schedule_epoch(&self, slot: Slot) -> Epoch {
        self.epoch_schedule.get_leader_schedule_epoch(slot)
    }

    /// a bank-level cache of vote accounts
    fn update_cached_accounts(
        &self,
        txs: &[Transaction],
        iteration_order: Option<&[usize]>,
        res: &[TransactionProcessResult],
        loaded: &[(Result<TransactionLoadResult>, Option<HashAgeKind>)],
    ) {
        for (i, ((raccs, _load_hash_age_kind), tx)) in loaded
            .iter()
            .zip(OrderedIterator::new(txs, iteration_order))
            .enumerate()
        {
            let (res, _res_hash_age_kind) = &res[i];
            if res.is_err() || raccs.is_err() {
                continue;
            }

            let message = &tx.message();
            let acc = raccs.as_ref().unwrap();

            for (pubkey, account) in message
                .account_keys
                .iter()
                .zip(acc.0.iter())
                .filter(|(_key, account)| (Stakes::is_stake(account)))
            {
                if Stakes::is_stake(account) {
                    self.stakes.write().unwrap().store(pubkey, account);
                }
            }
        }
    }

    /// current stake delegations for this bank
    /// Note: this method is exposed publicly for external usage
    pub fn stake_delegations(&self) -> HashMap<Pubkey, Delegation> {
        self.stakes.read().unwrap().stake_delegations().clone()
    }

    /// current vote accounts for this bank along with the stake
    ///   attributed to each account
    pub fn vote_accounts(&self) -> HashMap<Pubkey, (u64, Account)> {
        self.stakes.read().unwrap().vote_accounts().clone()
    }

    /// Get the EpochStakes for a given epoch
    pub fn epoch_stakes(&self, epoch: Epoch) -> Option<&EpochStakes> {
        self.epoch_stakes.get(&epoch)
    }

    pub fn epoch_stakes_map(&self) -> &HashMap<Epoch, EpochStakes> {
        &self.epoch_stakes
    }

    /// vote accounts for the specific epoch along with the stake
    ///   attributed to each account
    pub fn epoch_vote_accounts(&self, epoch: Epoch) -> Option<&HashMap<Pubkey, (u64, Account)>> {
        self.epoch_stakes
            .get(&epoch)
            .map(|epoch_stakes| Stakes::vote_accounts(epoch_stakes.stakes()))
    }

    /// Get the fixed authorized voter for the given vote account for the
    /// current epoch
    pub fn epoch_authorized_voter(&self, vote_account: &Pubkey) -> Option<&Pubkey> {
        self.epoch_stakes
            .get(&self.epoch)
            .expect("Epoch stakes for bank's own epoch must exist")
            .epoch_authorized_voters()
            .get(vote_account)
    }

    /// Get the fixed set of vote accounts for the given node id for the
    /// current epoch
    pub fn epoch_vote_accounts_for_node_id(&self, node_id: &Pubkey) -> Option<&NodeVoteAccounts> {
        self.epoch_stakes
            .get(&self.epoch)
            .expect("Epoch stakes for bank's own epoch must exist")
            .node_id_to_vote_accounts()
            .get(node_id)
    }

    /// Get the fixed total stake of all vote accounts for current epoch
    pub fn total_epoch_stake(&self) -> u64 {
        self.epoch_stakes
            .get(&self.epoch)
            .expect("Epoch stakes for bank's own epoch must exist")
            .total_stake()
    }

    /// Get the fixed stake of the given vote account for the current epoch
    pub fn epoch_vote_account_stake(&self, vote_account: &Pubkey) -> u64 {
        *self
            .epoch_vote_accounts(self.epoch())
            .expect("Bank epoch vote accounts must contain entry for the bank's own epoch")
            .get(vote_account)
            .map(|(stake, _)| stake)
            .unwrap_or(&0)
    }

    /// given a slot, return the epoch and offset into the epoch this slot falls
    /// e.g. with a fixed number for slots_per_epoch, the calculation is simply:
    ///
    ///  ( slot/slots_per_epoch, slot % slots_per_epoch )
    ///
    pub fn get_epoch_and_slot_index(&self, slot: Slot) -> (Epoch, SlotIndex) {
        self.epoch_schedule.get_epoch_and_slot_index(slot)
    }

    pub fn get_epoch_info(&self) -> EpochInfo {
        let absolute_slot = self.slot();
        let block_height = self.block_height();
        let (epoch, slot_index) = self.get_epoch_and_slot_index(absolute_slot);
        let slots_in_epoch = self.get_slots_in_epoch(epoch);
        EpochInfo {
            epoch,
            slot_index,
            slots_in_epoch,
            absolute_slot,
            block_height,
        }
    }

    pub fn is_empty(&self) -> bool {
        !self.is_delta.load(Ordering::Relaxed)
    }

    /// Add an instruction processor to intercept instructions before the dynamic loader.
    pub fn add_builtin_program(
        &mut self,
        name: &str,
        program_id: Pubkey,
        process_instruction: ProcessInstruction,
    ) {
        match self.get_account(&program_id) {
            Some(account) => {
                assert_eq!(
                    account.owner,
                    native_loader::id(),
                    "Cannot overwrite non-native loader account"
                );
            }
            None => {
                // Add a bogus executable native account, which will be loaded and ignored.
                let account = native_loader::create_loadable_account(name);
                self.store_account(&program_id, &account);
            }
        }
        self.message_processor
            .add_program(program_id, process_instruction);
        debug!("Added static program {} under {:?}", name, program_id);
    }

    pub fn compare_bank(&self, dbank: &Bank) {
        if ptr::eq(self, dbank) {
            return;
        }
        assert_eq!(self.slot, dbank.slot);
        assert_eq!(self.collector_id, dbank.collector_id);
        assert_eq!(self.epoch_schedule, dbank.epoch_schedule);
        assert_eq!(self.hashes_per_tick, dbank.hashes_per_tick);
        assert_eq!(self.ticks_per_slot, dbank.ticks_per_slot);
        assert_eq!(self.parent_hash, dbank.parent_hash);
        assert_eq!(
            self.tick_height.load(Ordering::Relaxed),
            dbank.tick_height.load(Ordering::Relaxed)
        );
        assert_eq!(
            self.is_delta.load(Ordering::Relaxed),
            dbank.is_delta.load(Ordering::Relaxed)
        );

        {
            let bh = self.hash.read().unwrap();
            let dbh = dbank.hash.read().unwrap();
            assert_eq!(*bh, *dbh);
        }

        {
            let st = self.stakes.read().unwrap();
            let dst = dbank.stakes.read().unwrap();
            assert_eq!(*st, *dst);
        }

        {
            let bhq = self.blockhash_queue.read().unwrap();
            let dbhq = dbank.blockhash_queue.read().unwrap();
            assert_eq!(*bhq, *dbhq);
        }

        {
            let sc = self.src.status_cache.read().unwrap();
            let dsc = dbank.src.status_cache.read().unwrap();
            assert_eq!(*sc, *dsc);
        }
        assert_eq!(
            self.rc.accounts.bank_hash_at(self.slot),
            dbank.rc.accounts.bank_hash_at(dbank.slot)
        );
    }

    pub fn clean_accounts(&self) {
        self.rc.accounts.accounts_db.clean_accounts();
    }

    pub fn process_dead_slots(&self) {
        self.rc.accounts.accounts_db.process_dead_slots(None);
    }

    pub fn shrink_all_slots(&self) {
        self.rc.accounts.accounts_db.shrink_all_slots();
    }

    pub fn print_accounts_stats(&self) {
        self.rc.accounts.accounts_db.print_accounts_stats("");
    }

    pub fn process_stale_slot_with_budget(
        &self,
        mut consumed_budget: usize,
        budget_recovery_delta: usize,
    ) -> usize {
        if consumed_budget == 0 {
            let shrunken_account_count = self.rc.accounts.accounts_db.process_stale_slot();
            if shrunken_account_count > 0 {
                datapoint_info!(
                    "stale_slot_shrink",
                    ("accounts", shrunken_account_count, i64)
                );
                consumed_budget += shrunken_account_count;
            }
        }
        consumed_budget.saturating_sub(budget_recovery_delta)
    }

    fn fix_recent_blockhashes_sysvar_delay(&self) -> bool {
        let activation_slot = match self.operating_mode() {
            OperatingMode::Development => 0,
            OperatingMode::Preview => 27_740_256, // Epoch 76
            OperatingMode::Stable => Slot::MAX / 2,
        };

        self.slot() >= activation_slot
    }
}

impl Drop for Bank {
    fn drop(&mut self) {
        // For root slots this is a noop
        if !self.skip_drop.load(Ordering::Relaxed) {
            self.rc.accounts.purge_slot(self.slot());
        }
    }
}

pub fn goto_end_of_slot(bank: &mut Bank) {
    let mut tick_hash = bank.last_blockhash();
    loop {
        tick_hash = hashv(&[&tick_hash.as_ref(), &[42]]);
        bank.register_tick(&tick_hash);
        if tick_hash == bank.last_blockhash() {
            bank.freeze();
            return;
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{
        accounts_index::{AccountMap, Ancestors},
        genesis_utils::{
            create_genesis_config_with_leader, GenesisConfigInfo, BOOTSTRAP_VALIDATOR_LAMPORTS,
        },
        status_cache::MAX_CACHE_ENTRIES,
    };
    use solana_sdk::{
        account::KeyedAccount,
        account_utils::StateMut,
        clock::{DEFAULT_SLOTS_PER_EPOCH, DEFAULT_TICKS_PER_SLOT},
        epoch_schedule::MINIMUM_SLOTS_PER_EPOCH,
        genesis_config::create_genesis_config,
        instruction::{AccountMeta, CompiledInstruction, Instruction, InstructionError},
        message::{Message, MessageHeader},
        nonce,
        poh_config::PohConfig,
        rent::Rent,
        signature::{Keypair, Signer},
        system_instruction, system_program,
        sysvar::{fees::Fees, rewards::Rewards},
        timing::duration_as_s,
    };
    use solana_stake_program::{
        stake_instruction,
        stake_state::{self, Authorized, Delegation, Lockup, Stake},
    };
    use solana_vote_program::vote_state::VoteStateVersions;
    use solana_vote_program::{
        vote_instruction,
        vote_state::{self, Vote, VoteInit, VoteState, MAX_LOCKOUT_HISTORY},
    };
    use std::{result, time::Duration};

    #[test]
    fn test_hash_age_kind_is_durable_nonce() {
        assert!(
            HashAgeKind::DurableNonce(Pubkey::default(), Account::default()).is_durable_nonce()
        );
        assert!(!HashAgeKind::Extant.is_durable_nonce());
    }

    #[test]
    fn test_bank_unix_timestamp() {
        let (genesis_config, _mint_keypair) = create_genesis_config(1);
        let mut bank = Arc::new(Bank::new(&genesis_config));

        assert_eq!(genesis_config.creation_time, bank.unix_timestamp());
        let slots_per_sec = 1.0
            / (duration_as_s(&genesis_config.poh_config.target_tick_duration)
                * genesis_config.ticks_per_slot as f32);

        for _i in 0..slots_per_sec as usize + 1 {
            bank = Arc::new(new_from_parent(&bank));
        }

        assert!(bank.unix_timestamp() - genesis_config.creation_time >= 1);
    }

    #[test]
    #[allow(clippy::float_cmp)]
    fn test_bank_new() {
        let dummy_leader_pubkey = Pubkey::new_rand();
        let dummy_leader_lamports = BOOTSTRAP_VALIDATOR_LAMPORTS;
        let mint_lamports = 10_000;
        let GenesisConfigInfo {
            mut genesis_config,
            mint_keypair,
            voting_keypair,
            ..
        } = create_genesis_config_with_leader(
            mint_lamports,
            &dummy_leader_pubkey,
            dummy_leader_lamports,
        );

        genesis_config.rent = Rent {
            lamports_per_byte_year: 5,
            exemption_threshold: 1.2,
            burn_percent: 5,
        };

        let bank = Bank::new(&genesis_config);
        assert_eq!(bank.get_balance(&mint_keypair.pubkey()), mint_lamports);
        assert_eq!(
            bank.get_balance(&voting_keypair.pubkey()),
            dummy_leader_lamports /* 1 token goes to the vote account associated with dummy_leader_lamports */
        );

        let rent_account = bank.get_account(&sysvar::rent::id()).unwrap();
        let rent = sysvar::rent::Rent::from_account(&rent_account).unwrap();

        assert_eq!(rent.burn_percent, 5);
        assert_eq!(rent.exemption_threshold, 1.2);
        assert_eq!(rent.lamports_per_byte_year, 5);
    }

    #[test]
    fn test_bank_block_height() {
        let (genesis_config, _mint_keypair) = create_genesis_config(1);
        let bank0 = Arc::new(Bank::new(&genesis_config));
        assert_eq!(bank0.block_height(), 0);
        let bank1 = Arc::new(new_from_parent(&bank0));
        assert_eq!(bank1.block_height(), 1);
    }

    #[test]
    fn test_bank_update_epoch_stakes() {
        impl Bank {
            fn epoch_stake_keys(&self) -> Vec<Epoch> {
                let mut keys: Vec<Epoch> = self.epoch_stakes.keys().copied().collect();
                keys.sort();
                keys
            }

            fn epoch_stake_key_info(&self) -> (Epoch, Epoch, usize) {
                let mut keys: Vec<Epoch> = self.epoch_stakes.keys().copied().collect();
                keys.sort();
                (*keys.first().unwrap(), *keys.last().unwrap(), keys.len())
            }
        }

        let (genesis_config, _mint_keypair) = create_genesis_config(100_000);
        let mut bank = Bank::new(&genesis_config);

        let initial_epochs = bank.epoch_stake_keys();
        assert_eq!(initial_epochs, vec![0, 1]);

        for existing_epoch in &initial_epochs {
            bank.update_epoch_stakes(*existing_epoch);
            assert_eq!(bank.epoch_stake_keys(), initial_epochs);
        }

        for epoch in (initial_epochs.len() as Epoch)..MAX_LEADER_SCHEDULE_STAKES {
            bank.update_epoch_stakes(epoch);
            assert_eq!(bank.epoch_stakes.len() as Epoch, epoch + 1);
        }

        assert_eq!(
            bank.epoch_stake_key_info(),
            (
                0,
                MAX_LEADER_SCHEDULE_STAKES - 1,
                MAX_LEADER_SCHEDULE_STAKES as usize
            )
        );

        bank.update_epoch_stakes(MAX_LEADER_SCHEDULE_STAKES);
        assert_eq!(
            bank.epoch_stake_key_info(),
            (
                0,
                MAX_LEADER_SCHEDULE_STAKES,
                MAX_LEADER_SCHEDULE_STAKES as usize + 1
            )
        );

        bank.update_epoch_stakes(MAX_LEADER_SCHEDULE_STAKES + 1);
        assert_eq!(
            bank.epoch_stake_key_info(),
            (
                1,
                MAX_LEADER_SCHEDULE_STAKES + 1,
                MAX_LEADER_SCHEDULE_STAKES as usize + 1
            )
        );
    }

    #[test]
    fn test_bank_capitalization() {
        let bank = Arc::new(Bank::new(&GenesisConfig {
            accounts: (0..42)
                .map(|_| (Pubkey::new_rand(), Account::new(42, 0, &Pubkey::default())))
                .collect(),
            ..GenesisConfig::default()
        }));
        assert_eq!(bank.capitalization(), 42 * 42);
        let bank1 = Bank::new_from_parent(&bank, &Pubkey::default(), 1);
        assert_eq!(bank1.capitalization(), 42 * 42);
    }

    #[test]
    fn test_credit_debit_rent_no_side_effect_on_hash() {
        let (mut genesis_config, _mint_keypair) = create_genesis_config(10);
        let keypair1: Keypair = Keypair::new();
        let keypair2: Keypair = Keypair::new();
        let keypair3: Keypair = Keypair::new();
        let keypair4: Keypair = Keypair::new();

        // Transaction between these two keypairs will fail
        let keypair5: Keypair = Keypair::new();
        let keypair6: Keypair = Keypair::new();

        genesis_config.rent = Rent {
            lamports_per_byte_year: 1,
            exemption_threshold: 21.0,
            burn_percent: 10,
        };

        let root_bank = Arc::new(Bank::new(&genesis_config));
        let bank = Bank::new_from_parent(
            &root_bank,
            &Pubkey::default(),
            years_as_slots(
                2.0,
                &genesis_config.poh_config.target_tick_duration,
                genesis_config.ticks_per_slot,
            ) as u64,
        );

        let root_bank_2 = Arc::new(Bank::new(&genesis_config));
        let bank_with_success_txs = Bank::new_from_parent(
            &root_bank_2,
            &Pubkey::default(),
            years_as_slots(
                2.0,
                &genesis_config.poh_config.target_tick_duration,
                genesis_config.ticks_per_slot,
            ) as u64,
        );

        assert_eq!(bank.last_blockhash(), genesis_config.hash());

        // Initialize credit-debit and credit only accounts
        let account1 = Account::new(264, 0, &Pubkey::default());
        let account2 = Account::new(264, 1, &Pubkey::default());
        let account3 = Account::new(264, 0, &Pubkey::default());
        let account4 = Account::new(264, 1, &Pubkey::default());
        let account5 = Account::new(10, 0, &Pubkey::default());
        let account6 = Account::new(10, 1, &Pubkey::default());

        bank.store_account(&keypair1.pubkey(), &account1);
        bank.store_account(&keypair2.pubkey(), &account2);
        bank.store_account(&keypair3.pubkey(), &account3);
        bank.store_account(&keypair4.pubkey(), &account4);
        bank.store_account(&keypair5.pubkey(), &account5);
        bank.store_account(&keypair6.pubkey(), &account6);

        bank_with_success_txs.store_account(&keypair1.pubkey(), &account1);
        bank_with_success_txs.store_account(&keypair2.pubkey(), &account2);
        bank_with_success_txs.store_account(&keypair3.pubkey(), &account3);
        bank_with_success_txs.store_account(&keypair4.pubkey(), &account4);
        bank_with_success_txs.store_account(&keypair5.pubkey(), &account5);
        bank_with_success_txs.store_account(&keypair6.pubkey(), &account6);

        // Make native instruction loader rent exempt
        let system_program_id = system_program::id();
        let mut system_program_account = bank.get_account(&system_program_id).unwrap();
        system_program_account.lamports =
            bank.get_minimum_balance_for_rent_exemption(system_program_account.data.len());
        bank.store_account(&system_program_id, &system_program_account);
        bank_with_success_txs.store_account(&system_program_id, &system_program_account);

        let t1 =
            system_transaction::transfer(&keypair1, &keypair2.pubkey(), 1, genesis_config.hash());
        let t2 =
            system_transaction::transfer(&keypair3, &keypair4.pubkey(), 1, genesis_config.hash());
        let t3 =
            system_transaction::transfer(&keypair5, &keypair6.pubkey(), 1, genesis_config.hash());

        let res = bank.process_transactions(&[t1.clone(), t2.clone(), t3]);

        assert_eq!(res.len(), 3);
        assert_eq!(res[0], Ok(()));
        assert_eq!(res[1], Ok(()));
        assert_eq!(res[2], Err(TransactionError::AccountNotFound));

        bank.freeze();

        let rwlockguard_bank_hash = bank.hash.read().unwrap();
        let bank_hash = rwlockguard_bank_hash.as_ref();

        let res = bank_with_success_txs.process_transactions(&[t2, t1]);

        assert_eq!(res.len(), 2);
        assert_eq!(res[0], Ok(()));
        assert_eq!(res[1], Ok(()));

        bank_with_success_txs.freeze();

        let rwlockguard_bank_with_success_txs_hash = bank_with_success_txs.hash.read().unwrap();
        let bank_with_success_txs_hash = rwlockguard_bank_with_success_txs_hash.as_ref();

        assert_eq!(bank_with_success_txs_hash, bank_hash);
    }

    #[derive(Serialize, Deserialize)]
    enum MockInstruction {
        Deduction,
    }

    fn mock_process_instruction(
        _program_id: &Pubkey,
        keyed_accounts: &[KeyedAccount],
        data: &[u8],
    ) -> result::Result<(), InstructionError> {
        if let Ok(instruction) = bincode::deserialize(data) {
            match instruction {
                MockInstruction::Deduction => {
                    keyed_accounts[1].account.borrow_mut().lamports += 1;
                    keyed_accounts[2].account.borrow_mut().lamports -= 1;
                    Ok(())
                }
            }
        } else {
            Err(InstructionError::InvalidInstructionData)
        }
    }

    fn create_mock_transaction(
        payer: &Keypair,
        keypair1: &Keypair,
        keypair2: &Keypair,
        read_only_keypair: &Keypair,
        mock_program_id: Pubkey,
        recent_blockhash: Hash,
    ) -> Transaction {
        let account_metas = vec![
            AccountMeta::new(payer.pubkey(), true),
            AccountMeta::new(keypair1.pubkey(), true),
            AccountMeta::new(keypair2.pubkey(), true),
            AccountMeta::new_readonly(read_only_keypair.pubkey(), false),
        ];
        let deduct_instruction =
            Instruction::new(mock_program_id, &MockInstruction::Deduction, account_metas);
        Transaction::new_signed_with_payer(
            &[deduct_instruction],
            Some(&payer.pubkey()),
            &[payer, keypair1, keypair2],
            recent_blockhash,
        )
    }

    fn store_accounts_for_rent_test(
        bank: &Bank,
        keypairs: &mut Vec<Keypair>,
        mock_program_id: Pubkey,
        generic_rent_due_for_system_account: u64,
    ) {
        let mut account_pairs: Vec<(Pubkey, Account)> = Vec::with_capacity(keypairs.len() - 1);
        account_pairs.push((
            keypairs[0].pubkey(),
            Account::new(
                generic_rent_due_for_system_account + 2,
                0,
                &Pubkey::default(),
            ),
        ));
        account_pairs.push((
            keypairs[1].pubkey(),
            Account::new(
                generic_rent_due_for_system_account + 2,
                0,
                &Pubkey::default(),
            ),
        ));
        account_pairs.push((
            keypairs[2].pubkey(),
            Account::new(
                generic_rent_due_for_system_account + 2,
                0,
                &Pubkey::default(),
            ),
        ));
        account_pairs.push((
            keypairs[3].pubkey(),
            Account::new(
                generic_rent_due_for_system_account + 2,
                0,
                &Pubkey::default(),
            ),
        ));
        account_pairs.push((
            keypairs[4].pubkey(),
            Account::new(10, 0, &Pubkey::default()),
        ));
        account_pairs.push((
            keypairs[5].pubkey(),
            Account::new(10, 0, &Pubkey::default()),
        ));
        account_pairs.push((
            keypairs[6].pubkey(),
            Account::new(
                (2 * generic_rent_due_for_system_account) + 24,
                0,
                &Pubkey::default(),
            ),
        ));

        account_pairs.push((
            keypairs[8].pubkey(),
            Account::new(
                generic_rent_due_for_system_account + 2 + 929,
                0,
                &Pubkey::default(),
            ),
        ));
        account_pairs.push((
            keypairs[9].pubkey(),
            Account::new(10, 0, &Pubkey::default()),
        ));

        // Feeding to MockProgram to test read only rent behaviour
        account_pairs.push((
            keypairs[10].pubkey(),
            Account::new(
                generic_rent_due_for_system_account + 3,
                0,
                &Pubkey::default(),
            ),
        ));
        account_pairs.push((
            keypairs[11].pubkey(),
            Account::new(generic_rent_due_for_system_account + 3, 0, &mock_program_id),
        ));
        account_pairs.push((
            keypairs[12].pubkey(),
            Account::new(generic_rent_due_for_system_account + 3, 0, &mock_program_id),
        ));
        account_pairs.push((
            keypairs[13].pubkey(),
            Account::new(14, 22, &mock_program_id),
        ));

        for account_pair in account_pairs.iter() {
            bank.store_account(&account_pair.0, &account_pair.1);
        }
    }

    fn create_child_bank_for_rent_test(
        root_bank: &Arc<Bank>,
        genesis_config: &GenesisConfig,
        mock_program_id: Pubkey,
    ) -> Bank {
        let mut bank = Bank::new_from_parent(
            root_bank,
            &Pubkey::default(),
            years_as_slots(
                2.0,
                &genesis_config.poh_config.target_tick_duration,
                genesis_config.ticks_per_slot,
            ) as u64,
        );
        bank.rent_collector.slots_per_year = 421_812.0;
        bank.add_builtin_program("mock_program", mock_program_id, mock_process_instruction);

        bank
    }

    #[test]
    fn test_rent_distribution() {
        let bootstrap_validator_pubkey = Pubkey::new_rand();
        let bootstrap_validator_stake_lamports = 30;
        let mut genesis_config = create_genesis_config_with_leader(
            10,
            &bootstrap_validator_pubkey,
            bootstrap_validator_stake_lamports,
        )
        .genesis_config;

        genesis_config.epoch_schedule = EpochSchedule::custom(
            MINIMUM_SLOTS_PER_EPOCH,
            genesis_config.epoch_schedule.leader_schedule_slot_offset,
            false,
        );

        genesis_config.rent = Rent {
            lamports_per_byte_year: 1,
            exemption_threshold: 2.0,
            burn_percent: 10,
        };

        let rent = Rent::free();

        let validator_1_pubkey = Pubkey::new_rand();
        let validator_1_stake_lamports = 20;
        let validator_1_staking_keypair = Keypair::new();
        let validator_1_voting_keypair = Keypair::new();

        let validator_1_vote_account = vote_state::create_account(
            &validator_1_voting_keypair.pubkey(),
            &validator_1_pubkey,
            0,
            validator_1_stake_lamports,
        );

        let validator_1_stake_account = stake_state::create_account(
            &validator_1_staking_keypair.pubkey(),
            &validator_1_voting_keypair.pubkey(),
            &validator_1_vote_account,
            &rent,
            validator_1_stake_lamports,
        );

        genesis_config.accounts.insert(
            validator_1_pubkey,
            Account::new(42, 0, &system_program::id()),
        );
        genesis_config.accounts.insert(
            validator_1_staking_keypair.pubkey(),
            validator_1_stake_account,
        );
        genesis_config.accounts.insert(
            validator_1_voting_keypair.pubkey(),
            validator_1_vote_account,
        );

        let validator_2_pubkey = Pubkey::new_rand();
        let validator_2_stake_lamports = 20;
        let validator_2_staking_keypair = Keypair::new();
        let validator_2_voting_keypair = Keypair::new();

        let validator_2_vote_account = vote_state::create_account(
            &validator_2_voting_keypair.pubkey(),
            &validator_2_pubkey,
            0,
            validator_2_stake_lamports,
        );

        let validator_2_stake_account = stake_state::create_account(
            &validator_2_staking_keypair.pubkey(),
            &validator_2_voting_keypair.pubkey(),
            &validator_2_vote_account,
            &rent,
            validator_2_stake_lamports,
        );

        genesis_config.accounts.insert(
            validator_2_pubkey,
            Account::new(42, 0, &system_program::id()),
        );
        genesis_config.accounts.insert(
            validator_2_staking_keypair.pubkey(),
            validator_2_stake_account,
        );
        genesis_config.accounts.insert(
            validator_2_voting_keypair.pubkey(),
            validator_2_vote_account,
        );

        let validator_3_pubkey = Pubkey::new_rand();
        let validator_3_stake_lamports = 30;
        let validator_3_staking_keypair = Keypair::new();
        let validator_3_voting_keypair = Keypair::new();

        let validator_3_vote_account = vote_state::create_account(
            &validator_3_voting_keypair.pubkey(),
            &validator_3_pubkey,
            0,
            validator_3_stake_lamports,
        );

        let validator_3_stake_account = stake_state::create_account(
            &validator_3_staking_keypair.pubkey(),
            &validator_3_voting_keypair.pubkey(),
            &validator_3_vote_account,
            &rent,
            validator_3_stake_lamports,
        );

        genesis_config.accounts.insert(
            validator_3_pubkey,
            Account::new(42, 0, &system_program::id()),
        );
        genesis_config.accounts.insert(
            validator_3_staking_keypair.pubkey(),
            validator_3_stake_account,
        );
        genesis_config.accounts.insert(
            validator_3_voting_keypair.pubkey(),
            validator_3_vote_account,
        );

        genesis_config.rent = Rent {
            lamports_per_byte_year: 1,
            exemption_threshold: 10.0,
            burn_percent: 10,
        };

        let mut bank = Bank::new(&genesis_config);
        // Enable rent collection
        bank.rent_collector.epoch = 5;
        bank.rent_collector.slots_per_year = 192.0;

        let payer = Keypair::new();
        let payer_account = Account::new(400, 0, &system_program::id());
        bank.store_account(&payer.pubkey(), &payer_account);

        let payee = Keypair::new();
        let payee_account = Account::new(70, 1, &system_program::id());
        bank.store_account(&payee.pubkey(), &payee_account);

        let bootstrap_validator_initial_balance = bank.get_balance(&bootstrap_validator_pubkey);

        let tx = system_transaction::transfer(&payer, &payee.pubkey(), 180, genesis_config.hash());

        let result = bank.process_transaction(&tx);
        assert_eq!(result, Ok(()));

        let mut total_rent_deducted = 0;

        // 400 - 128(Rent) - 180(Transfer)
        assert_eq!(bank.get_balance(&payer.pubkey()), 92);
        total_rent_deducted += 128;

        // 70 - 70(Rent) + 180(Transfer) - 21(Rent)
        assert_eq!(bank.get_balance(&payee.pubkey()), 159);
        total_rent_deducted += 70 + 21;

        let previous_capitalization = bank.capitalization.load(Ordering::Relaxed);

        bank.freeze();

        assert_eq!(
            bank.collected_rent.load(Ordering::Relaxed),
            total_rent_deducted
        );

        let burned_portion =
            total_rent_deducted * u64::from(bank.rent_collector.rent.burn_percent) / 100;
        let rent_to_be_distributed = total_rent_deducted - burned_portion;

        let bootstrap_validator_portion =
            ((bootstrap_validator_stake_lamports * rent_to_be_distributed) as f64 / 100.0) as u64
                + 1; // Leftover lamport
        assert_eq!(
            bank.get_balance(&bootstrap_validator_pubkey),
            bootstrap_validator_portion + bootstrap_validator_initial_balance
        );

        // Since, validator 1 and validator 2 has equal smallest stake, it comes down to comparison
        // between their pubkey.
        let tweak_1 = if validator_1_pubkey > validator_2_pubkey {
            1
        } else {
            0
        };
        let validator_1_portion =
            ((validator_1_stake_lamports * rent_to_be_distributed) as f64 / 100.0) as u64 + tweak_1;
        assert_eq!(
            bank.get_balance(&validator_1_pubkey),
            validator_1_portion + 42 - tweak_1,
        );

        // Since, validator 1 and validator 2 has equal smallest stake, it comes down to comparison
        // between their pubkey.
        let tweak_2 = if validator_2_pubkey > validator_1_pubkey {
            1
        } else {
            0
        };
        let validator_2_portion =
            ((validator_2_stake_lamports * rent_to_be_distributed) as f64 / 100.0) as u64 + tweak_2;
        assert_eq!(
            bank.get_balance(&validator_2_pubkey),
            validator_2_portion + 42 - tweak_2,
        );

        let validator_3_portion =
            ((validator_3_stake_lamports * rent_to_be_distributed) as f64 / 100.0) as u64 + 1;
        assert_eq!(
            bank.get_balance(&validator_3_pubkey),
            validator_3_portion + 42
        );

        let current_capitalization = bank.capitalization.load(Ordering::Relaxed);

        assert_eq!(
            previous_capitalization - current_capitalization,
            burned_portion
        );
    }

    #[test]
    fn test_rent_exempt_executable_account() {
        let (mut genesis_config, mint_keypair) = create_genesis_config(100_000);
        genesis_config.rent = Rent {
            lamports_per_byte_year: 1,
            exemption_threshold: 1000.0,
            burn_percent: 10,
        };

        let root_bank = Arc::new(Bank::new(&genesis_config));
        let bank = create_child_bank_for_rent_test(&root_bank, &genesis_config, Pubkey::new_rand());

        let account_pubkey = Pubkey::new_rand();
        let account_balance = 1;
        let mut account = Account::new(account_balance, 0, &Pubkey::new_rand());
        account.executable = true;
        bank.store_account(&account_pubkey, &account);

        let transfer_lamports = 1;
        let tx = system_transaction::transfer(
            &mint_keypair,
            &account_pubkey,
            transfer_lamports,
            genesis_config.hash(),
        );

        assert_eq!(
            bank.process_transaction(&tx),
            Err(TransactionError::InstructionError(
                0,
                InstructionError::ExecutableLamportChange
            ))
        );
        assert_eq!(bank.get_balance(&account_pubkey), account_balance);
    }

    #[test]
    #[allow(clippy::cognitive_complexity)]
    fn test_rent_complex() {
        solana_logger::setup();
        let mock_program_id = Pubkey::new(&[2u8; 32]);

        let (mut genesis_config, _mint_keypair) = create_genesis_config(10);
        let mut keypairs: Vec<Keypair> = Vec::with_capacity(14);
        for _i in 0..14 {
            keypairs.push(Keypair::new());
        }

        genesis_config.rent = Rent {
            lamports_per_byte_year: 1,
            exemption_threshold: 1000.0,
            burn_percent: 10,
        };

        let root_bank = Bank::new(&genesis_config);
        // until we completely transition to the eager rent collection,
        // we must ensure lazy rent collection doens't get broken!
        root_bank
            .lazy_rent_collection
            .store(true, Ordering::Relaxed);
        let root_bank = Arc::new(root_bank);
        let bank = create_child_bank_for_rent_test(&root_bank, &genesis_config, mock_program_id);

        assert_eq!(bank.last_blockhash(), genesis_config.hash());

        let slots_elapsed: u64 = (0..=bank.epoch)
            .map(|epoch| {
                bank.rent_collector
                    .epoch_schedule
                    .get_slots_in_epoch(epoch + 1)
            })
            .sum();
        let (generic_rent_due_for_system_account, _) = bank.rent_collector.rent.due(
            bank.get_minimum_balance_for_rent_exemption(0) - 1,
            0,
            slots_elapsed as f64 / bank.rent_collector.slots_per_year,
        );

        store_accounts_for_rent_test(
            &bank,
            &mut keypairs,
            mock_program_id,
            generic_rent_due_for_system_account,
        );

        let magic_rent_number = 131; // yuck, derive this value programmatically one day

        let t1 = system_transaction::transfer(
            &keypairs[0],
            &keypairs[1].pubkey(),
            1,
            genesis_config.hash(),
        );
        let t2 = system_transaction::transfer(
            &keypairs[2],
            &keypairs[3].pubkey(),
            1,
            genesis_config.hash(),
        );
        let t3 = system_transaction::transfer(
            &keypairs[4],
            &keypairs[5].pubkey(),
            1,
            genesis_config.hash(),
        );
        let t4 = system_transaction::transfer(
            &keypairs[6],
            &keypairs[7].pubkey(),
            generic_rent_due_for_system_account + 1,
            genesis_config.hash(),
        );
        let t5 = system_transaction::transfer(
            &keypairs[8],
            &keypairs[9].pubkey(),
            929,
            genesis_config.hash(),
        );

        let t6 = create_mock_transaction(
            &keypairs[10],
            &keypairs[11],
            &keypairs[12],
            &keypairs[13],
            mock_program_id,
            genesis_config.hash(),
        );

        let res = bank.process_transactions(&[t6, t5, t1, t2, t3, t4]);

        assert_eq!(res.len(), 6);
        assert_eq!(res[0], Ok(()));
        assert_eq!(res[1], Ok(()));
        assert_eq!(res[2], Ok(()));
        assert_eq!(res[3], Ok(()));
        assert_eq!(res[4], Err(TransactionError::AccountNotFound));
        assert_eq!(res[5], Ok(()));

        bank.freeze();

        let mut rent_collected = 0;

        // 48992 - generic_rent_due_for_system_account(Rent) - 1(transfer)
        assert_eq!(bank.get_balance(&keypairs[0].pubkey()), 1);
        rent_collected += generic_rent_due_for_system_account;

        // 48992 - generic_rent_due_for_system_account(Rent) + 1(transfer)
        assert_eq!(bank.get_balance(&keypairs[1].pubkey()), 3);
        rent_collected += generic_rent_due_for_system_account;

        // 48992 - generic_rent_due_for_system_account(Rent) - 1(transfer)
        assert_eq!(bank.get_balance(&keypairs[2].pubkey()), 1);
        rent_collected += generic_rent_due_for_system_account;

        // 48992 - generic_rent_due_for_system_account(Rent) + 1(transfer)
        assert_eq!(bank.get_balance(&keypairs[3].pubkey()), 3);
        rent_collected += generic_rent_due_for_system_account;

        // No rent deducted
        assert_eq!(bank.get_balance(&keypairs[4].pubkey()), 10);
        assert_eq!(bank.get_balance(&keypairs[5].pubkey()), 10);

        // 98004 - generic_rent_due_for_system_account(Rent) - 48991(transfer)
        assert_eq!(bank.get_balance(&keypairs[6].pubkey()), 23);
        rent_collected += generic_rent_due_for_system_account;

        // 0 + 48990(transfer) - magic_rent_number(Rent)
        assert_eq!(
            bank.get_balance(&keypairs[7].pubkey()),
            generic_rent_due_for_system_account + 1 - magic_rent_number
        );

        // Epoch should be updated
        // Rent deducted on store side
        let account8 = bank.get_account(&keypairs[7].pubkey()).unwrap();
        // Epoch should be set correctly.
        assert_eq!(account8.rent_epoch, bank.epoch + 1);
        rent_collected += magic_rent_number;

        // 49921 - generic_rent_due_for_system_account(Rent) - 929(Transfer)
        assert_eq!(bank.get_balance(&keypairs[8].pubkey()), 2);
        rent_collected += generic_rent_due_for_system_account;

        let account10 = bank.get_account(&keypairs[9].pubkey()).unwrap();
        // Account was overwritten at load time, since it didn't have sufficient balance to pay rent
        // Then, at store time we deducted `magic_rent_number` rent for the current epoch, once it has balance
        assert_eq!(account10.rent_epoch, bank.epoch + 1);
        // account data is blank now
        assert_eq!(account10.data.len(), 0);
        // 10 - 10(Rent) + 929(Transfer) - magic_rent_number(Rent)
        assert_eq!(account10.lamports, 929 - magic_rent_number);
        rent_collected += magic_rent_number + 10;

        // 48993 - generic_rent_due_for_system_account(Rent)
        assert_eq!(bank.get_balance(&keypairs[10].pubkey()), 3);
        rent_collected += generic_rent_due_for_system_account;

        // 48993 - generic_rent_due_for_system_account(Rent) + 1(Addition by program)
        assert_eq!(bank.get_balance(&keypairs[11].pubkey()), 4);
        rent_collected += generic_rent_due_for_system_account;

        // 48993 - generic_rent_due_for_system_account(Rent) - 1(Deduction by program)
        assert_eq!(bank.get_balance(&keypairs[12].pubkey()), 2);
        rent_collected += generic_rent_due_for_system_account;

        // No rent for read-only account
        assert_eq!(bank.get_balance(&keypairs[13].pubkey()), 14);

        // Bank's collected rent should be sum of rent collected from all accounts
        assert_eq!(bank.collected_rent.load(Ordering::Relaxed), rent_collected);
    }

    #[test]
    fn test_rent_eager_across_epoch_without_gap() {
        let (genesis_config, _mint_keypair) = create_genesis_config(1);

        let mut bank = Arc::new(Bank::new(&genesis_config));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 32)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 1, 32)]);
        for _ in 2..32 {
            bank = Arc::new(new_from_parent(&bank));
        }
        assert_eq!(bank.rent_collection_partitions(), vec![(30, 31, 32)]);
        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 64)]);
    }

    #[test]
    fn test_rent_eager_across_epoch_with_full_gap() {
        let (genesis_config, _mint_keypair) = create_genesis_config(1);

        let mut bank = Arc::new(Bank::new(&genesis_config));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 32)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 1, 32)]);
        for _ in 2..15 {
            bank = Arc::new(new_from_parent(&bank));
        }
        assert_eq!(bank.rent_collection_partitions(), vec![(13, 14, 32)]);
        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 49));
        assert_eq!(
            bank.rent_collection_partitions(),
            vec![(14, 31, 32), (0, 0, 64), (0, 17, 64)]
        );
        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.rent_collection_partitions(), vec![(17, 18, 64)]);
    }

    #[test]
    fn test_rent_eager_across_epoch_with_half_gap() {
        let (genesis_config, _mint_keypair) = create_genesis_config(1);

        let mut bank = Arc::new(Bank::new(&genesis_config));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 32)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 1, 32)]);
        for _ in 2..15 {
            bank = Arc::new(new_from_parent(&bank));
        }
        assert_eq!(bank.rent_collection_partitions(), vec![(13, 14, 32)]);
        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 32));
        assert_eq!(
            bank.rent_collection_partitions(),
            vec![(14, 31, 32), (0, 0, 64)]
        );
        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 1, 64)]);
    }

    #[test]
    #[allow(clippy::cognitive_complexity)]
    fn test_rent_eager_across_epoch_without_gap_under_multi_epoch_cycle() {
        let leader_pubkey = Pubkey::new_rand();
        let leader_lamports = 3;
        let mut genesis_config =
            create_genesis_config_with_leader(5, &leader_pubkey, leader_lamports).genesis_config;
        genesis_config.operating_mode = OperatingMode::Stable;

        const SLOTS_PER_EPOCH: u64 = MINIMUM_SLOTS_PER_EPOCH as u64;
        const LEADER_SCHEDULE_SLOT_OFFSET: u64 = SLOTS_PER_EPOCH * 3 - 3;
        genesis_config.epoch_schedule =
            EpochSchedule::custom(SLOTS_PER_EPOCH, LEADER_SCHEDULE_SLOT_OFFSET, false);

        let mut bank = Arc::new(Bank::new(&genesis_config));
        assert_eq!(DEFAULT_SLOTS_PER_EPOCH, 432_000);
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (0, 0));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 432_000)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (0, 1));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 1, 432_000)]);

        for _ in 2..32 {
            bank = Arc::new(new_from_parent(&bank));
        }
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (0, 31));
        assert_eq!(bank.rent_collection_partitions(), vec![(30, 31, 432_000)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (1, 0));
        assert_eq!(bank.rent_collection_partitions(), vec![(31, 32, 432_000)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (1, 1));
        assert_eq!(bank.rent_collection_partitions(), vec![(32, 33, 432_000)]);

        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 1000));
        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 1001));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (31, 9));
        assert_eq!(
            bank.rent_collection_partitions(),
            vec![(1000, 1001, 432_000)]
        );

        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 431_998));
        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 431_999));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (13499, 31));
        assert_eq!(
            bank.rent_collection_partitions(),
            vec![(431_998, 431_999, 432_000)]
        );

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (13500, 0));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 432_000)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (13500, 1));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 1, 432_000)]);
    }

    #[test]
    fn test_rent_eager_across_epoch_with_gap_under_multi_epoch_cycle() {
        let leader_pubkey = Pubkey::new_rand();
        let leader_lamports = 3;
        let mut genesis_config =
            create_genesis_config_with_leader(5, &leader_pubkey, leader_lamports).genesis_config;
        genesis_config.operating_mode = OperatingMode::Stable;

        const SLOTS_PER_EPOCH: u64 = MINIMUM_SLOTS_PER_EPOCH as u64;
        const LEADER_SCHEDULE_SLOT_OFFSET: u64 = SLOTS_PER_EPOCH * 3 - 3;
        genesis_config.epoch_schedule =
            EpochSchedule::custom(SLOTS_PER_EPOCH, LEADER_SCHEDULE_SLOT_OFFSET, false);

        let mut bank = Arc::new(Bank::new(&genesis_config));
        assert_eq!(DEFAULT_SLOTS_PER_EPOCH, 432_000);
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (0, 0));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 432_000)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (0, 1));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 1, 432_000)]);

        for _ in 2..19 {
            bank = Arc::new(new_from_parent(&bank));
        }
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (0, 18));
        assert_eq!(bank.rent_collection_partitions(), vec![(17, 18, 432_000)]);

        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 44));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (1, 12));
        assert_eq!(
            bank.rent_collection_partitions(),
            vec![(18, 31, 432_000), (31, 31, 432_000), (31, 44, 432_000)]
        );

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (1, 13));
        assert_eq!(bank.rent_collection_partitions(), vec![(44, 45, 432_000)]);

        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 431_993));
        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 432_011));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (13500, 11));
        assert_eq!(
            bank.rent_collection_partitions(),
            vec![
                (431_993, 431_999, 432_000),
                (0, 0, 432_000),
                (0, 11, 432_000)
            ]
        );
    }

    #[test]
    fn test_rent_eager_with_warmup_epochs_under_multi_epoch_cycle() {
        let leader_pubkey = Pubkey::new_rand();
        let leader_lamports = 3;
        let mut genesis_config =
            create_genesis_config_with_leader(5, &leader_pubkey, leader_lamports).genesis_config;
        genesis_config.operating_mode = OperatingMode::Stable;

        const SLOTS_PER_EPOCH: u64 = MINIMUM_SLOTS_PER_EPOCH as u64 * 8;
        const LEADER_SCHEDULE_SLOT_OFFSET: u64 = SLOTS_PER_EPOCH * 3 - 3;
        genesis_config.epoch_schedule =
            EpochSchedule::custom(SLOTS_PER_EPOCH, LEADER_SCHEDULE_SLOT_OFFSET, true);

        let mut bank = Arc::new(Bank::new(&genesis_config));
        assert_eq!(DEFAULT_SLOTS_PER_EPOCH, 432_000);
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.first_normal_epoch(), 3);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (0, 0));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 32)]);

        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 222));
        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 128);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (2, 127));
        assert_eq!(bank.rent_collection_partitions(), vec![(126, 127, 128)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 256);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (3, 0));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 431_872)]);
        assert_eq!(431_872 % bank.get_slots_in_epoch(bank.epoch()), 0);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 256);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (3, 1));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 1, 431_872)]);

        bank = Arc::new(Bank::new_from_parent(
            &bank,
            &Pubkey::default(),
            431_872 + 223 - 1,
        ));
        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 256);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (1689, 255));
        assert_eq!(
            bank.rent_collection_partitions(),
            vec![(431_870, 431_871, 431_872)]
        );

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 256);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (1690, 0));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 431_872)]);
    }

    #[test]
    fn test_rent_eager_under_fixed_cycle_for_developemnt() {
        solana_logger::setup();
        let leader_pubkey = Pubkey::new_rand();
        let leader_lamports = 3;
        let mut genesis_config =
            create_genesis_config_with_leader(5, &leader_pubkey, leader_lamports).genesis_config;

        const SLOTS_PER_EPOCH: u64 = MINIMUM_SLOTS_PER_EPOCH as u64 * 8;
        const LEADER_SCHEDULE_SLOT_OFFSET: u64 = SLOTS_PER_EPOCH * 3 - 3;
        genesis_config.epoch_schedule =
            EpochSchedule::custom(SLOTS_PER_EPOCH, LEADER_SCHEDULE_SLOT_OFFSET, true);

        let mut bank = Arc::new(Bank::new(&genesis_config));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 32);
        assert_eq!(bank.first_normal_epoch(), 3);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (0, 0));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 432_000)]);

        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), 222));
        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 128);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (2, 127));
        assert_eq!(bank.rent_collection_partitions(), vec![(222, 223, 432_000)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 256);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (3, 0));
        assert_eq!(bank.rent_collection_partitions(), vec![(223, 224, 432_000)]);

        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_slots_in_epoch(bank.epoch()), 256);
        assert_eq!(bank.get_epoch_and_slot_index(bank.slot()), (3, 1));
        assert_eq!(bank.rent_collection_partitions(), vec![(224, 225, 432_000)]);

        bank = Arc::new(Bank::new_from_parent(
            &bank,
            &Pubkey::default(),
            432_000 - 2,
        ));
        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(
            bank.rent_collection_partitions(),
            vec![(431_998, 431_999, 432_000)]
        );
        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 0, 432_000)]);
        bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.rent_collection_partitions(), vec![(0, 1, 432_000)]);

        bank = Arc::new(Bank::new_from_parent(
            &bank,
            &Pubkey::default(),
            864_000 - 20,
        ));
        bank = Arc::new(Bank::new_from_parent(
            &bank,
            &Pubkey::default(),
            864_000 + 39,
        ));
        assert_eq!(
            bank.rent_collection_partitions(),
            vec![
                (431_980, 431_999, 432_000),
                (0, 0, 432_000),
                (0, 39, 432_000)
            ]
        );
    }

    #[test]
    fn test_rent_eager_pubkey_range_minimal() {
        let range = Bank::pubkey_range_from_partition((0, 0, 1));
        assert_eq!(
            range,
            Pubkey::new_from_array([0x00; 32])..=Pubkey::new_from_array([0xff; 32])
        );
    }

    #[test]
    fn test_rent_eager_pubkey_range_maximum() {
        let max = !0;

        let range = Bank::pubkey_range_from_partition((0, 0, max));
        assert_eq!(
            range,
            Pubkey::new_from_array([0x00; 32])
                ..=Pubkey::new_from_array([
                    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        let range = Bank::pubkey_range_from_partition((0, 1, max));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00,
            ])
                ..=Pubkey::new_from_array([
                    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        let range = Bank::pubkey_range_from_partition((max - 3, max - 2, max));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00,
            ])
                ..=Pubkey::new_from_array([
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        let range = Bank::pubkey_range_from_partition((max - 2, max - 1, max));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00,
            ])
                ..=Pubkey::new_from_array([
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
    }

    fn map_to_test_bad_range() -> AccountMap<Pubkey, i8> {
        let mut map: AccountMap<Pubkey, i8> = AccountMap::new();
        // when empty, AccountMap (= std::collections::BTreeMap) doesn't sanitize given range...
        map.insert(Pubkey::new_rand(), 1);
        map
    }

    #[test]
    #[should_panic(expected = "range start is greater than range end in BTreeMap")]
    fn test_rent_eager_bad_range() {
        let test_map = map_to_test_bad_range();
        test_map.range(
            Pubkey::new_from_array([
                0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x01,
            ])
                ..=Pubkey::new_from_array([
                    0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0x00, 0x00, 0x00, 0x00, 0x00,
                    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                    0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                ]),
        );
    }

    #[test]
    fn test_rent_eager_pubkey_range_noop_range() {
        let test_map = map_to_test_bad_range();

        let range = Bank::pubkey_range_from_partition((0, 0, 3));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00
            ])
                ..=Pubkey::new_from_array([
                    0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x54, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        test_map.range(range);

        let range = Bank::pubkey_range_from_partition((1, 1, 3));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00
            ])
                ..=Pubkey::new_from_array([
                    0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0x00, 0x00, 0x00, 0x00, 0x00,
                    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                    0x00, 0x00, 0x00, 0x00, 0x00, 0x00
                ])
        );
        test_map.range(range);

        let range = Bank::pubkey_range_from_partition((2, 2, 3));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                0xff, 0xff, 0xff, 0xff
            ])
                ..=Pubkey::new_from_array([
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        test_map.range(range);
    }

    #[test]
    fn test_rent_eager_pubkey_range_dividable() {
        let test_map = map_to_test_bad_range();
        let range = Bank::pubkey_range_from_partition((0, 0, 2));

        assert_eq!(
            range,
            Pubkey::new_from_array([
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00
            ])
                ..=Pubkey::new_from_array([
                    0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        test_map.range(range);

        let range = Bank::pubkey_range_from_partition((0, 1, 2));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00
            ])
                ..=Pubkey::new_from_array([
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        test_map.range(range);
    }

    #[test]
    fn test_rent_eager_pubkey_range_not_dividable() {
        solana_logger::setup();

        let test_map = map_to_test_bad_range();
        let range = Bank::pubkey_range_from_partition((0, 0, 3));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00
            ])
                ..=Pubkey::new_from_array([
                    0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x54, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        test_map.range(range);

        let range = Bank::pubkey_range_from_partition((0, 1, 3));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00
            ])
                ..=Pubkey::new_from_array([
                    0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xa9, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        test_map.range(range);

        let range = Bank::pubkey_range_from_partition((1, 2, 3));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00
            ])
                ..=Pubkey::new_from_array([
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        test_map.range(range);
    }

    #[test]
    fn test_rent_eager_pubkey_range_gap() {
        solana_logger::setup();

        let test_map = map_to_test_bad_range();
        let range = Bank::pubkey_range_from_partition((120, 1023, 12345));
        assert_eq!(
            range,
            Pubkey::new_from_array([
                0x02, 0x82, 0x5a, 0x89, 0xd1, 0xac, 0x58, 0x9c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                0x00, 0x00, 0x00, 0x00
            ])
                ..=Pubkey::new_from_array([
                    0x15, 0x3c, 0x1d, 0xf1, 0xc6, 0x39, 0xef, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                    0xff, 0xff, 0xff, 0xff, 0xff, 0xff
                ])
        );
        test_map.range(range);
    }

    impl Bank {
        fn slots_by_pubkey(&self, pubkey: &Pubkey, ancestors: &Ancestors) -> Vec<Slot> {
            let accounts_index = self.rc.accounts.accounts_db.accounts_index.read().unwrap();
            let (accounts, _) = accounts_index.get(&pubkey, Some(&ancestors)).unwrap();
            accounts
                .iter()
                .map(|(slot, _)| *slot)
                .collect::<Vec<Slot>>()
        }
    }

    #[test]
    fn test_rent_eager_collect_rent_in_partition() {
        solana_logger::setup();

        let (genesis_config, _mint_keypair) = create_genesis_config(1);

        let zero_lamport_pubkey = Pubkey::new_rand();
        let rent_due_pubkey = Pubkey::new_rand();
        let rent_exempt_pubkey = Pubkey::new_rand();

        let mut bank = Arc::new(Bank::new(&genesis_config));
        let zero_lamports = 0;
        let little_lamports = 1234;
        let large_lamports = 123_456_789;
        let rent_collected = 22;

        bank.store_account(
            &zero_lamport_pubkey,
            &Account::new(zero_lamports, 0, &Pubkey::default()),
        );
        bank.store_account(
            &rent_due_pubkey,
            &Account::new(little_lamports, 0, &Pubkey::default()),
        );
        bank.store_account(
            &rent_exempt_pubkey,
            &Account::new(large_lamports, 0, &Pubkey::default()),
        );

        let genesis_slot = 0;
        let some_slot = 1000;
        let ancestors = vec![(some_slot, 0), (0, 1)].into_iter().collect();

        bank = Arc::new(Bank::new_from_parent(&bank, &Pubkey::default(), some_slot));

        assert_eq!(bank.collected_rent.load(Ordering::Relaxed), 0);
        assert_eq!(
            bank.get_account(&rent_due_pubkey).unwrap().lamports,
            little_lamports
        );
        assert_eq!(bank.get_account(&rent_due_pubkey).unwrap().rent_epoch, 0);
        assert_eq!(
            bank.slots_by_pubkey(&rent_due_pubkey, &ancestors),
            vec![genesis_slot]
        );
        assert_eq!(
            bank.slots_by_pubkey(&rent_exempt_pubkey, &ancestors),
            vec![genesis_slot]
        );
        assert_eq!(
            bank.slots_by_pubkey(&zero_lamport_pubkey, &ancestors),
            vec![genesis_slot]
        );

        bank.collect_rent_in_partition((0, 0, 1)); // all range

        // unrelated 1-lamport account exists
        assert_eq!(
            bank.collected_rent.load(Ordering::Relaxed),
            rent_collected + 1
        );
        assert_eq!(
            bank.get_account(&rent_due_pubkey).unwrap().lamports,
            little_lamports - rent_collected
        );
        assert_eq!(bank.get_account(&rent_due_pubkey).unwrap().rent_epoch, 6);
        assert_eq!(
            bank.get_account(&rent_exempt_pubkey).unwrap().lamports,
            large_lamports
        );
        assert_eq!(bank.get_account(&rent_exempt_pubkey).unwrap().rent_epoch, 6);
        assert_eq!(
            bank.slots_by_pubkey(&rent_due_pubkey, &ancestors),
            vec![genesis_slot, some_slot]
        );
        assert_eq!(
            bank.slots_by_pubkey(&rent_exempt_pubkey, &ancestors),
            vec![genesis_slot, some_slot]
        );
        assert_eq!(
            bank.slots_by_pubkey(&zero_lamport_pubkey, &ancestors),
            vec![genesis_slot]
        );
    }

    #[test]
    fn test_rent_eager_collect_rent_zero_lamport_deterministic() {
        solana_logger::setup();

        let (genesis_config, _mint_keypair) = create_genesis_config(1);

        let zero_lamport_pubkey = Pubkey::new_rand();

        let genesis_bank1 = Arc::new(Bank::new(&genesis_config));
        let genesis_bank2 = Arc::new(Bank::new(&genesis_config));
        let bank1_with_zero = Arc::new(new_from_parent(&genesis_bank1));
        let bank1_without_zero = Arc::new(new_from_parent(&genesis_bank2));
        let zero_lamports = 0;

        let account = Account::new(zero_lamports, 0, &Pubkey::default());
        bank1_with_zero.store_account(&zero_lamport_pubkey, &account);
        bank1_without_zero.store_account(&zero_lamport_pubkey, &account);

        bank1_without_zero
            .rc
            .accounts
            .accounts_db
            .accounts_index
            .write()
            .unwrap()
            .add_root(genesis_bank1.slot() + 1);
        bank1_without_zero
            .rc
            .accounts
            .accounts_db
            .accounts_index
            .write()
            .unwrap()
            .purge(&zero_lamport_pubkey);

        let some_slot = 1000;
        let bank2_with_zero = Arc::new(Bank::new_from_parent(
            &bank1_with_zero,
            &Pubkey::default(),
            some_slot,
        ));
        let bank2_without_zero = Arc::new(Bank::new_from_parent(
            &bank1_without_zero,
            &Pubkey::default(),
            some_slot,
        ));
        let hash1_with_zero = bank1_with_zero.hash();
        let hash1_without_zero = bank1_without_zero.hash();
        assert_eq!(hash1_with_zero, hash1_without_zero);
        assert_ne!(hash1_with_zero, Hash::default());

        bank2_with_zero.collect_rent_in_partition((0, 0, 1)); // all
        bank2_without_zero.collect_rent_in_partition((0, 0, 1)); // all

        bank2_with_zero.freeze();
        let hash2_with_zero = bank2_with_zero.hash();
        bank2_without_zero.freeze();
        let hash2_without_zero = bank2_without_zero.hash();

        assert_eq!(hash2_with_zero, hash2_without_zero);
        assert_ne!(hash2_with_zero, Hash::default());
    }

    #[test]
    fn test_bank_update_rewards() {
        // create a bank that ticks really slowly...
        let bank = Arc::new(Bank::new(&GenesisConfig {
            accounts: (0..42)
                .map(|_| {
                    (
                        Pubkey::new_rand(),
                        Account::new(1_000_000_000, 0, &Pubkey::default()),
                    )
                })
                .collect(),
            // set it up so the first epoch is a full year long
            poh_config: PohConfig {
                target_tick_duration: Duration::from_secs(
                    SECONDS_PER_YEAR as u64
                        / MINIMUM_SLOTS_PER_EPOCH as u64
                        / DEFAULT_TICKS_PER_SLOT,
                ),
                hashes_per_tick: None,
                target_tick_count: None,
            },

            ..GenesisConfig::default()
        }));

        // enable lazy rent collection because this test depends on rent-due accounts
        // not being eagerly-collected for exact rewards calculation
        bank.lazy_rent_collection.store(true, Ordering::Relaxed);

        assert_eq!(bank.capitalization(), 42 * 1_000_000_000);
        assert_eq!(bank.rewards, None);

        let ((vote_id, mut vote_account), (stake_id, stake_account)) =
            crate::stakes::tests::create_staked_node_accounts(1_0000);

        // set up accounts
        bank.store_account(&stake_id, &stake_account);

        // generate some rewards
        let mut vote_state = Some(VoteState::from(&vote_account).unwrap());
        for i in 0..MAX_LOCKOUT_HISTORY + 42 {
            if let Some(v) = vote_state.as_mut() {
                v.process_slot_vote_unchecked(i as u64)
            }
            let versioned = VoteStateVersions::Current(Box::new(vote_state.take().unwrap()));
            VoteState::to(&versioned, &mut vote_account).unwrap();
            bank.store_account(&vote_id, &vote_account);
            match versioned {
                VoteStateVersions::Current(v) => {
                    vote_state = Some(*v);
                }
                _ => panic!("Has to be of type Current"),
            };
        }
        bank.store_account(&vote_id, &vote_account);

        let validator_points: u128 = bank
            .stake_delegation_accounts()
            .iter()
            .flat_map(|(_vote_pubkey, (stake_group, vote_account))| {
                stake_group
                    .iter()
                    .map(move |(_stake_pubkey, stake_account)| (stake_account, vote_account))
            })
            .map(|(stake_account, vote_account)| {
                stake_state::calculate_points(&stake_account, &vote_account, None).unwrap_or(0)
            })
            .sum();

        // put a child bank in epoch 1, which calls update_rewards()...
        let bank1 = Bank::new_from_parent(
            &bank,
            &Pubkey::default(),
            bank.get_slots_in_epoch(bank.epoch()) + 1,
        );
        // verify that there's inflation
        assert_ne!(bank1.capitalization(), bank.capitalization());

        // verify the inflation is represented in validator_points *
        let inflation = bank1.capitalization() - bank.capitalization();

        let rewards = bank1
            .get_account(&sysvar::rewards::id())
            .map(|account| Rewards::from_account(&account).unwrap())
            .unwrap();

        // verify the stake and vote accounts are the right size
        assert!(
            ((bank1.get_balance(&stake_id) - stake_account.lamports + bank1.get_balance(&vote_id)
                - vote_account.lamports) as f64
                - rewards.validator_point_value * validator_points as f64)
                .abs()
                < 1.0
        );

        // verify the rewards are the right size
        assert!(
            ((rewards.validator_point_value * validator_points as f64) - inflation as f64).abs()
                < 1.0 // rounding, truncating
        );

        // verify validator rewards show up in bank1.rewards vector
        assert_eq!(
            bank1.rewards,
            Some(vec![(
                stake_id,
                (rewards.validator_point_value * validator_points as f64) as i64
            )])
        );
    }

    fn do_test_bank_update_rewards_determinism() -> u64 {
        // create a bank that ticks really slowly...
        let bank = Arc::new(Bank::new(&GenesisConfig {
            accounts: (0..42)
                .map(|_| {
                    (
                        Pubkey::new_rand(),
                        Account::new(1_000_000_000, 0, &Pubkey::default()),
                    )
                })
                .collect(),
            // set it up so the first epoch is a full year long
            poh_config: PohConfig {
                target_tick_duration: Duration::from_secs(
                    SECONDS_PER_YEAR as u64
                        / MINIMUM_SLOTS_PER_EPOCH as u64
                        / DEFAULT_TICKS_PER_SLOT,
                ),
                hashes_per_tick: None,
                target_tick_count: None,
            },

            ..GenesisConfig::default()
        }));

        // enable lazy rent collection because this test depends on rent-due accounts
        // not being eagerly-collected for exact rewards calculation
        bank.lazy_rent_collection.store(true, Ordering::Relaxed);

        assert_eq!(bank.capitalization(), 42 * 1_000_000_000);
        assert_eq!(bank.rewards, None);

        let vote_id = Pubkey::new_rand();
        let mut vote_account = vote_state::create_account(&vote_id, &Pubkey::new_rand(), 50, 100);
        let (stake_id1, stake_account1) = crate::stakes::tests::create_stake_account(123, &vote_id);
        let (stake_id2, stake_account2) = crate::stakes::tests::create_stake_account(456, &vote_id);

        // set up accounts
        bank.store_account(&stake_id1, &stake_account1);
        bank.store_account(&stake_id2, &stake_account2);

        // generate some rewards
        let mut vote_state = Some(VoteState::from(&vote_account).unwrap());
        for i in 0..MAX_LOCKOUT_HISTORY + 42 {
            if let Some(v) = vote_state.as_mut() {
                v.process_slot_vote_unchecked(i as u64)
            }
            let versioned = VoteStateVersions::Current(Box::new(vote_state.take().unwrap()));
            VoteState::to(&versioned, &mut vote_account).unwrap();
            bank.store_account(&vote_id, &vote_account);
            match versioned {
                VoteStateVersions::Current(v) => {
                    vote_state = Some(*v);
                }
                _ => panic!("Has to be of type Current"),
            };
        }
        bank.store_account(&vote_id, &vote_account);

        // put a child bank in epoch 1, which calls update_rewards()...
        let bank1 = Bank::new_from_parent(
            &bank,
            &Pubkey::default(),
            bank.get_slots_in_epoch(bank.epoch()) + 1,
        );
        // verify that there's inflation
        assert_ne!(bank1.capitalization(), bank.capitalization());

        bank1.capitalization()
    }

    #[test]
    fn test_bank_update_rewards_determinism() {
        // The same reward should be distributed given same credits
        let expected_capitalization = do_test_bank_update_rewards_determinism();
        // Repeat somewhat large number of iterations to expose possible different behavior
        // depending on the randamly-seeded HashMap ordering
        for _ in 0..30 {
            let actual_capitalization = do_test_bank_update_rewards_determinism();
            assert_eq!(actual_capitalization, expected_capitalization);
        }
    }

    // Test that purging 0 lamports accounts works.
    #[test]
    fn test_purge_empty_accounts() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(500_000);
        let parent = Arc::new(Bank::new(&genesis_config));
        let mut bank = parent;
        for _ in 0..10 {
            let blockhash = bank.last_blockhash();
            let pubkey = Pubkey::new_rand();
            let tx = system_transaction::transfer(&mint_keypair, &pubkey, 0, blockhash);
            bank.process_transaction(&tx).unwrap();
            bank.squash();
            bank = Arc::new(new_from_parent(&bank));
        }

        let hash = bank.update_accounts_hash();
        bank.clean_accounts();
        assert_eq!(bank.update_accounts_hash(), hash);

        let bank0 = Arc::new(new_from_parent(&bank));
        let blockhash = bank.last_blockhash();
        let keypair = Keypair::new();
        let tx = system_transaction::transfer(&mint_keypair, &keypair.pubkey(), 10, blockhash);
        bank0.process_transaction(&tx).unwrap();

        let bank1 = Arc::new(new_from_parent(&bank0));
        let pubkey = Pubkey::new_rand();
        let blockhash = bank.last_blockhash();
        let tx = system_transaction::transfer(&keypair, &pubkey, 10, blockhash);
        bank1.process_transaction(&tx).unwrap();

        assert_eq!(bank0.get_account(&keypair.pubkey()).unwrap().lamports, 10);
        assert_eq!(bank1.get_account(&keypair.pubkey()), None);

        info!("bank0 purge");
        let hash = bank0.update_accounts_hash();
        bank0.clean_accounts();
        assert_eq!(bank0.update_accounts_hash(), hash);

        assert_eq!(bank0.get_account(&keypair.pubkey()).unwrap().lamports, 10);
        assert_eq!(bank1.get_account(&keypair.pubkey()), None);

        info!("bank1 purge");
        bank1.clean_accounts();

        assert_eq!(bank0.get_account(&keypair.pubkey()).unwrap().lamports, 10);
        assert_eq!(bank1.get_account(&keypair.pubkey()), None);

        assert!(bank0.verify_bank_hash());

        // Squash and then verify hash_internal value
        bank0.squash();
        assert!(bank0.verify_bank_hash());

        bank1.squash();
        bank1.update_accounts_hash();
        assert!(bank1.verify_bank_hash());

        // keypair should have 0 tokens on both forks
        assert_eq!(bank0.get_account(&keypair.pubkey()), None);
        assert_eq!(bank1.get_account(&keypair.pubkey()), None);
        bank1.clean_accounts();

        assert!(bank1.verify_bank_hash());
    }

    #[test]
    fn test_two_payments_to_one_party() {
        let (genesis_config, mint_keypair) = create_genesis_config(10_000);
        let pubkey = Pubkey::new_rand();
        let bank = Bank::new(&genesis_config);
        assert_eq!(bank.last_blockhash(), genesis_config.hash());

        bank.transfer(1_000, &mint_keypair, &pubkey).unwrap();
        assert_eq!(bank.get_balance(&pubkey), 1_000);

        bank.transfer(500, &mint_keypair, &pubkey).unwrap();
        assert_eq!(bank.get_balance(&pubkey), 1_500);
        assert_eq!(bank.transaction_count(), 2);
    }

    #[test]
    fn test_one_source_two_tx_one_batch() {
        let (genesis_config, mint_keypair) = create_genesis_config(1);
        let key1 = Pubkey::new_rand();
        let key2 = Pubkey::new_rand();
        let bank = Bank::new(&genesis_config);
        assert_eq!(bank.last_blockhash(), genesis_config.hash());

        let t1 = system_transaction::transfer(&mint_keypair, &key1, 1, genesis_config.hash());
        let t2 = system_transaction::transfer(&mint_keypair, &key2, 1, genesis_config.hash());
        let res = bank.process_transactions(&[t1.clone(), t2.clone()]);

        assert_eq!(res.len(), 2);
        assert_eq!(res[0], Ok(()));
        assert_eq!(res[1], Err(TransactionError::AccountInUse));
        assert_eq!(bank.get_balance(&mint_keypair.pubkey()), 0);
        assert_eq!(bank.get_balance(&key1), 1);
        assert_eq!(bank.get_balance(&key2), 0);
        assert_eq!(bank.get_signature_status(&t1.signatures[0]), Some(Ok(())));
        // TODO: Transactions that fail to pay a fee could be dropped silently.
        // Non-instruction errors don't get logged in the signature cache
        assert_eq!(bank.get_signature_status(&t2.signatures[0]), None);
    }

    #[test]
    fn test_one_tx_two_out_atomic_fail() {
        let (genesis_config, mint_keypair) = create_genesis_config(1);
        let key1 = Pubkey::new_rand();
        let key2 = Pubkey::new_rand();
        let bank = Bank::new(&genesis_config);
        let instructions =
            system_instruction::transfer_many(&mint_keypair.pubkey(), &[(key1, 1), (key2, 1)]);
        let message = Message::new(&instructions, Some(&mint_keypair.pubkey()));
        let tx = Transaction::new(&[&mint_keypair], message, genesis_config.hash());
        assert_eq!(
            bank.process_transaction(&tx).unwrap_err(),
            TransactionError::InstructionError(
                1,
                InstructionError::new_result_with_negative_lamports(),
            )
        );
        assert_eq!(bank.get_balance(&mint_keypair.pubkey()), 1);
        assert_eq!(bank.get_balance(&key1), 0);
        assert_eq!(bank.get_balance(&key2), 0);
    }

    #[test]
    fn test_one_tx_two_out_atomic_pass() {
        let (genesis_config, mint_keypair) = create_genesis_config(2);
        let key1 = Pubkey::new_rand();
        let key2 = Pubkey::new_rand();
        let bank = Bank::new(&genesis_config);
        let instructions =
            system_instruction::transfer_many(&mint_keypair.pubkey(), &[(key1, 1), (key2, 1)]);
        let message = Message::new(&instructions, Some(&mint_keypair.pubkey()));
        let tx = Transaction::new(&[&mint_keypair], message, genesis_config.hash());
        bank.process_transaction(&tx).unwrap();
        assert_eq!(bank.get_balance(&mint_keypair.pubkey()), 0);
        assert_eq!(bank.get_balance(&key1), 1);
        assert_eq!(bank.get_balance(&key2), 1);
    }

    // This test demonstrates that fees are paid even when a program fails.
    #[test]
    fn test_detect_failed_duplicate_transactions() {
        let (mut genesis_config, mint_keypair) = create_genesis_config(2);
        genesis_config.fee_rate_governor = FeeRateGovernor::new(1, 0);
        let bank = Bank::new(&genesis_config);

        let dest = Keypair::new();

        // source with 0 program context
        let tx =
            system_transaction::transfer(&mint_keypair, &dest.pubkey(), 2, genesis_config.hash());
        let signature = tx.signatures[0];
        assert!(!bank.has_signature(&signature));

        assert_eq!(
            bank.process_transaction(&tx),
            Err(TransactionError::InstructionError(
                0,
                InstructionError::new_result_with_negative_lamports(),
            ))
        );

        // The lamports didn't move, but the from address paid the transaction fee.
        assert_eq!(bank.get_balance(&dest.pubkey()), 0);

        // This should be the original balance minus the transaction fee.
        assert_eq!(bank.get_balance(&mint_keypair.pubkey()), 1);
    }

    #[test]
    fn test_account_not_found() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(0);
        let bank = Bank::new(&genesis_config);
        let keypair = Keypair::new();
        assert_eq!(
            bank.transfer(1, &keypair, &mint_keypair.pubkey()),
            Err(TransactionError::AccountNotFound)
        );
        assert_eq!(bank.transaction_count(), 0);
    }

    #[test]
    fn test_insufficient_funds() {
        let (genesis_config, mint_keypair) = create_genesis_config(11_000);
        let bank = Bank::new(&genesis_config);
        let pubkey = Pubkey::new_rand();
        bank.transfer(1_000, &mint_keypair, &pubkey).unwrap();
        assert_eq!(bank.transaction_count(), 1);
        assert_eq!(bank.get_balance(&pubkey), 1_000);
        assert_eq!(
            bank.transfer(10_001, &mint_keypair, &pubkey),
            Err(TransactionError::InstructionError(
                0,
                InstructionError::new_result_with_negative_lamports(),
            ))
        );
        assert_eq!(bank.transaction_count(), 1);

        let mint_pubkey = mint_keypair.pubkey();
        assert_eq!(bank.get_balance(&mint_pubkey), 10_000);
        assert_eq!(bank.get_balance(&pubkey), 1_000);
    }

    #[test]
    fn test_transfer_to_newb() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(10_000);
        let bank = Bank::new(&genesis_config);
        let pubkey = Pubkey::new_rand();
        bank.transfer(500, &mint_keypair, &pubkey).unwrap();
        assert_eq!(bank.get_balance(&pubkey), 500);
    }

    #[test]
    fn test_transfer_to_sysvar() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(10_000);
        let bank = Arc::new(Bank::new(&genesis_config));

        let normal_pubkey = Pubkey::new_rand();
        let sysvar_pubkey = sysvar::clock::id();
        assert_eq!(bank.get_balance(&normal_pubkey), 0);
        assert_eq!(bank.get_balance(&sysvar_pubkey), 1);

        bank.transfer(500, &mint_keypair, &normal_pubkey).unwrap();
        bank.transfer(500, &mint_keypair, &sysvar_pubkey).unwrap();
        assert_eq!(bank.get_balance(&normal_pubkey), 500);
        assert_eq!(bank.get_balance(&sysvar_pubkey), 501);

        let bank = Arc::new(new_from_parent(&bank));
        assert_eq!(bank.get_balance(&normal_pubkey), 500);
        assert_eq!(bank.get_balance(&sysvar_pubkey), 501);
    }

    #[test]
    fn test_bank_deposit() {
        let (genesis_config, _mint_keypair) = create_genesis_config(100);
        let bank = Bank::new(&genesis_config);

        // Test new account
        let key = Keypair::new();
        bank.deposit(&key.pubkey(), 10);
        assert_eq!(bank.get_balance(&key.pubkey()), 10);

        // Existing account
        bank.deposit(&key.pubkey(), 3);
        assert_eq!(bank.get_balance(&key.pubkey()), 13);
    }

    #[test]
    fn test_bank_withdraw() {
        let (genesis_config, _mint_keypair) = create_genesis_config(100);
        let bank = Bank::new(&genesis_config);

        // Test no account
        let key = Keypair::new();
        assert_eq!(
            bank.withdraw(&key.pubkey(), 10),
            Err(TransactionError::AccountNotFound)
        );

        bank.deposit(&key.pubkey(), 3);
        assert_eq!(bank.get_balance(&key.pubkey()), 3);

        // Low balance
        assert_eq!(
            bank.withdraw(&key.pubkey(), 10),
            Err(TransactionError::InsufficientFundsForFee)
        );

        // Enough balance
        assert_eq!(bank.withdraw(&key.pubkey(), 2), Ok(()));
        assert_eq!(bank.get_balance(&key.pubkey()), 1);
    }

    #[test]
    fn test_bank_withdraw_from_nonce_account() {
        let (mut genesis_config, _mint_keypair) = create_genesis_config(100_000);
        genesis_config.rent.lamports_per_byte_year = 42;
        let bank = Bank::new(&genesis_config);

        let min_balance = bank.get_minimum_balance_for_rent_exemption(nonce::State::size());
        let nonce = Keypair::new();
        let nonce_account = Account::new_data(
            min_balance + 42,
            &nonce::state::Versions::new_current(nonce::State::Initialized(
                nonce::state::Data::default(),
            )),
            &system_program::id(),
        )
        .unwrap();
        bank.store_account(&nonce.pubkey(), &nonce_account);
        assert_eq!(bank.get_balance(&nonce.pubkey()), min_balance + 42);

        // Resulting in non-zero, but sub-min_balance balance fails
        assert_eq!(
            bank.withdraw(&nonce.pubkey(), min_balance / 2),
            Err(TransactionError::InsufficientFundsForFee)
        );
        assert_eq!(bank.get_balance(&nonce.pubkey()), min_balance + 42);

        // Resulting in exactly rent-exempt balance succeeds
        bank.withdraw(&nonce.pubkey(), 42).unwrap();
        assert_eq!(bank.get_balance(&nonce.pubkey()), min_balance);

        // Account closure fails
        assert_eq!(
            bank.withdraw(&nonce.pubkey(), min_balance),
            Err(TransactionError::InsufficientFundsForFee),
        );
    }

    #[test]
    fn test_bank_tx_fee() {
        let arbitrary_transfer_amount = 42;
        let mint = arbitrary_transfer_amount * 100;
        let leader = Pubkey::new_rand();
        let GenesisConfigInfo {
            mut genesis_config,
            mint_keypair,
            ..
        } = create_genesis_config_with_leader(mint, &leader, 3);
        genesis_config.fee_rate_governor = FeeRateGovernor::new(4, 0); // something divisible by 2

        let expected_fee_paid = genesis_config
            .fee_rate_governor
            .create_fee_calculator()
            .lamports_per_signature;
        let (expected_fee_collected, expected_fee_burned) =
            genesis_config.fee_rate_governor.burn(expected_fee_paid);

        let mut bank = Bank::new(&genesis_config);

        let capitalization = bank.capitalization();

        let key = Keypair::new();
        let tx = system_transaction::transfer(
            &mint_keypair,
            &key.pubkey(),
            arbitrary_transfer_amount,
            bank.last_blockhash(),
        );

        let initial_balance = bank.get_balance(&leader);
        assert_eq!(bank.process_transaction(&tx), Ok(()));
        assert_eq!(bank.get_balance(&key.pubkey()), arbitrary_transfer_amount);
        assert_eq!(
            bank.get_balance(&mint_keypair.pubkey()),
            mint - arbitrary_transfer_amount - expected_fee_paid
        );

        assert_eq!(bank.get_balance(&leader), initial_balance);
        goto_end_of_slot(&mut bank);
        assert_eq!(bank.signature_count(), 1);
        assert_eq!(
            bank.get_balance(&leader),
            initial_balance + expected_fee_collected
        ); // Leader collects fee after the bank is frozen

        // verify capitalization
        assert_eq!(capitalization - expected_fee_burned, bank.capitalization());

        // Verify that an InstructionError collects fees, too
        let mut bank = Bank::new_from_parent(&Arc::new(bank), &leader, 1);
        let mut tx =
            system_transaction::transfer(&mint_keypair, &key.pubkey(), 1, bank.last_blockhash());
        // Create a bogus instruction to system_program to cause an instruction error
        tx.message.instructions[0].data[0] = 40;

        bank.process_transaction(&tx)
            .expect_err("instruction error");
        assert_eq!(bank.get_balance(&key.pubkey()), arbitrary_transfer_amount); // no change
        assert_eq!(
            bank.get_balance(&mint_keypair.pubkey()),
            mint - arbitrary_transfer_amount - 2 * expected_fee_paid
        ); // mint_keypair still pays a fee
        goto_end_of_slot(&mut bank);
        assert_eq!(bank.signature_count(), 1);

        // Profit! 2 transaction signatures processed at 3 lamports each
        assert_eq!(
            bank.get_balance(&leader),
            initial_balance + 2 * expected_fee_collected
        );
    }

    #[test]
    fn test_bank_blockhash_fee_schedule() {
        //solana_logger::setup();

        let leader = Pubkey::new_rand();
        let GenesisConfigInfo {
            mut genesis_config,
            mint_keypair,
            ..
        } = create_genesis_config_with_leader(1_000_000, &leader, 3);
        genesis_config
            .fee_rate_governor
            .target_lamports_per_signature = 1000;
        genesis_config.fee_rate_governor.target_signatures_per_slot = 1;

        let mut bank = Bank::new(&genesis_config);
        goto_end_of_slot(&mut bank);
        let (cheap_blockhash, cheap_fee_calculator) = bank.last_blockhash_with_fee_calculator();
        assert_eq!(cheap_fee_calculator.lamports_per_signature, 0);

        let mut bank = Bank::new_from_parent(&Arc::new(bank), &leader, 1);
        goto_end_of_slot(&mut bank);
        let (expensive_blockhash, expensive_fee_calculator) =
            bank.last_blockhash_with_fee_calculator();
        assert!(
            cheap_fee_calculator.lamports_per_signature
                < expensive_fee_calculator.lamports_per_signature
        );

        let bank = Bank::new_from_parent(&Arc::new(bank), &leader, 2);

        // Send a transfer using cheap_blockhash
        let key = Keypair::new();
        let initial_mint_balance = bank.get_balance(&mint_keypair.pubkey());
        let tx = system_transaction::transfer(&mint_keypair, &key.pubkey(), 1, cheap_blockhash);
        assert_eq!(bank.process_transaction(&tx), Ok(()));
        assert_eq!(bank.get_balance(&key.pubkey()), 1);
        assert_eq!(
            bank.get_balance(&mint_keypair.pubkey()),
            initial_mint_balance - 1 - cheap_fee_calculator.lamports_per_signature
        );

        // Send a transfer using expensive_blockhash
        let key = Keypair::new();
        let initial_mint_balance = bank.get_balance(&mint_keypair.pubkey());
        let tx = system_transaction::transfer(&mint_keypair, &key.pubkey(), 1, expensive_blockhash);
        assert_eq!(bank.process_transaction(&tx), Ok(()));
        assert_eq!(bank.get_balance(&key.pubkey()), 1);
        assert_eq!(
            bank.get_balance(&mint_keypair.pubkey()),
            initial_mint_balance - 1 - expensive_fee_calculator.lamports_per_signature
        );
    }

    #[test]
    fn test_filter_program_errors_and_collect_fee() {
        let leader = Pubkey::new_rand();
        let GenesisConfigInfo {
            mut genesis_config,
            mint_keypair,
            ..
        } = create_genesis_config_with_leader(100, &leader, 3);
        genesis_config.fee_rate_governor = FeeRateGovernor::new(2, 0);
        let bank = Bank::new(&genesis_config);

        let key = Keypair::new();
        let tx1 =
            system_transaction::transfer(&mint_keypair, &key.pubkey(), 2, genesis_config.hash());
        let tx2 =
            system_transaction::transfer(&mint_keypair, &key.pubkey(), 5, genesis_config.hash());

        let results = vec![
            (Ok(()), Some(HashAgeKind::Extant)),
            (
                Err(TransactionError::InstructionError(
                    1,
                    InstructionError::new_result_with_negative_lamports(),
                )),
                Some(HashAgeKind::Extant),
            ),
        ];
        let initial_balance = bank.get_balance(&leader);

        let results = bank.filter_program_errors_and_collect_fee(&[tx1, tx2], None, &results);
        bank.freeze();
        assert_eq!(
            bank.get_balance(&leader),
            initial_balance
                + bank
                    .fee_rate_governor
                    .burn(bank.fee_calculator.lamports_per_signature * 2)
                    .0
        );
        assert_eq!(results[0], Ok(()));
        assert_eq!(results[1], Ok(()));
    }

    #[test]
    fn test_debits_before_credits() {
        let (genesis_config, mint_keypair) = create_genesis_config(2);
        let bank = Bank::new(&genesis_config);
        let keypair = Keypair::new();
        let tx0 = system_transaction::transfer(
            &mint_keypair,
            &keypair.pubkey(),
            2,
            genesis_config.hash(),
        );
        let tx1 = system_transaction::transfer(
            &keypair,
            &mint_keypair.pubkey(),
            1,
            genesis_config.hash(),
        );
        let txs = vec![tx0, tx1];
        let results = bank.process_transactions(&txs);
        assert!(results[1].is_err());

        // Assert bad transactions aren't counted.
        assert_eq!(bank.transaction_count(), 1);
    }

    #[test]
    fn test_readonly_accounts() {
        let GenesisConfigInfo {
            genesis_config,
            mint_keypair,
            ..
        } = create_genesis_config_with_leader(500, &Pubkey::new_rand(), 0);
        let bank = Bank::new(&genesis_config);

        let vote_pubkey0 = Pubkey::new_rand();
        let vote_pubkey1 = Pubkey::new_rand();
        let vote_pubkey2 = Pubkey::new_rand();
        let authorized_voter = Keypair::new();
        let payer0 = Keypair::new();
        let payer1 = Keypair::new();

        // Create vote accounts
        let vote_account0 =
            vote_state::create_account(&vote_pubkey0, &authorized_voter.pubkey(), 0, 100);
        let vote_account1 =
            vote_state::create_account(&vote_pubkey1, &authorized_voter.pubkey(), 0, 100);
        let vote_account2 =
            vote_state::create_account(&vote_pubkey2, &authorized_voter.pubkey(), 0, 100);
        bank.store_account(&vote_pubkey0, &vote_account0);
        bank.store_account(&vote_pubkey1, &vote_account1);
        bank.store_account(&vote_pubkey2, &vote_account2);

        // Fund payers
        bank.transfer(10, &mint_keypair, &payer0.pubkey()).unwrap();
        bank.transfer(10, &mint_keypair, &payer1.pubkey()).unwrap();
        bank.transfer(1, &mint_keypair, &authorized_voter.pubkey())
            .unwrap();

        let vote = Vote::new(vec![1], Hash::default());
        let ix0 = vote_instruction::vote(&vote_pubkey0, &authorized_voter.pubkey(), vote.clone());
        let tx0 = Transaction::new_signed_with_payer(
            &[ix0],
            Some(&payer0.pubkey()),
            &[&payer0, &authorized_voter],
            bank.last_blockhash(),
        );
        let ix1 = vote_instruction::vote(&vote_pubkey1, &authorized_voter.pubkey(), vote.clone());
        let tx1 = Transaction::new_signed_with_payer(
            &[ix1],
            Some(&payer1.pubkey()),
            &[&payer1, &authorized_voter],
            bank.last_blockhash(),
        );
        let txs = vec![tx0, tx1];
        let results = bank.process_transactions(&txs);

        // If multiple transactions attempt to read the same account, they should succeed.
        // Vote authorized_voter and sysvar accounts are given read-only handling
        assert_eq!(results[0], Ok(()));
        assert_eq!(results[1], Ok(()));

        let ix0 = vote_instruction::vote(&vote_pubkey2, &authorized_voter.pubkey(), vote);
        let tx0 = Transaction::new_signed_with_payer(
            &[ix0],
            Some(&payer0.pubkey()),
            &[&payer0, &authorized_voter],
            bank.last_blockhash(),
        );
        let tx1 = system_transaction::transfer(
            &authorized_voter,
            &Pubkey::new_rand(),
            1,
            bank.last_blockhash(),
        );
        let txs = vec![tx0, tx1];
        let results = bank.process_transactions(&txs);
        // However, an account may not be locked as read-only and writable at the same time.
        assert_eq!(results[0], Ok(()));
        assert_eq!(results[1], Err(TransactionError::AccountInUse));
    }

    #[test]
    fn test_interleaving_locks() {
        let (genesis_config, mint_keypair) = create_genesis_config(3);
        let bank = Bank::new(&genesis_config);
        let alice = Keypair::new();
        let bob = Keypair::new();

        let tx1 =
            system_transaction::transfer(&mint_keypair, &alice.pubkey(), 1, genesis_config.hash());
        let pay_alice = vec![tx1];

        let lock_result = bank.prepare_batch(&pay_alice, None);
        let results_alice = bank
            .load_execute_and_commit_transactions(&lock_result, MAX_PROCESSING_AGE, false)
            .0
            .fee_collection_results;
        assert_eq!(results_alice[0], Ok(()));

        // try executing an interleaved transfer twice
        assert_eq!(
            bank.transfer(1, &mint_keypair, &bob.pubkey()),
            Err(TransactionError::AccountInUse)
        );
        // the second time should fail as well
        // this verifies that `unlock_accounts` doesn't unlock `AccountInUse` accounts
        assert_eq!(
            bank.transfer(1, &mint_keypair, &bob.pubkey()),
            Err(TransactionError::AccountInUse)
        );

        drop(lock_result);

        assert!(bank.transfer(2, &mint_keypair, &bob.pubkey()).is_ok());
    }

    #[test]
    fn test_readonly_relaxed_locks() {
        let (genesis_config, _) = create_genesis_config(3);
        let bank = Bank::new(&genesis_config);
        let key0 = Keypair::new();
        let key1 = Keypair::new();
        let key2 = Keypair::new();
        let key3 = Pubkey::new_rand();

        let message = Message {
            header: MessageHeader {
                num_required_signatures: 1,
                num_readonly_signed_accounts: 0,
                num_readonly_unsigned_accounts: 1,
            },
            account_keys: vec![key0.pubkey(), key3],
            recent_blockhash: Hash::default(),
            instructions: vec![],
        };
        let tx = Transaction::new(&[&key0], message, genesis_config.hash());
        let txs = vec![tx];

        let batch0 = bank.prepare_batch(&txs, None);
        assert!(batch0.lock_results()[0].is_ok());

        // Try locking accounts, locking a previously read-only account as writable
        // should fail
        let message = Message {
            header: MessageHeader {
                num_required_signatures: 1,
                num_readonly_signed_accounts: 0,
                num_readonly_unsigned_accounts: 0,
            },
            account_keys: vec![key1.pubkey(), key3],
            recent_blockhash: Hash::default(),
            instructions: vec![],
        };
        let tx = Transaction::new(&[&key1], message, genesis_config.hash());
        let txs = vec![tx];

        let batch1 = bank.prepare_batch(&txs, None);
        assert!(batch1.lock_results()[0].is_err());

        // Try locking a previously read-only account a 2nd time; should succeed
        let message = Message {
            header: MessageHeader {
                num_required_signatures: 1,
                num_readonly_signed_accounts: 0,
                num_readonly_unsigned_accounts: 1,
            },
            account_keys: vec![key2.pubkey(), key3],
            recent_blockhash: Hash::default(),
            instructions: vec![],
        };
        let tx = Transaction::new(&[&key2], message, genesis_config.hash());
        let txs = vec![tx];

        let batch2 = bank.prepare_batch(&txs, None);
        assert!(batch2.lock_results()[0].is_ok());
    }

    #[test]
    fn test_bank_invalid_account_index() {
        let (genesis_config, mint_keypair) = create_genesis_config(1);
        let keypair = Keypair::new();
        let bank = Bank::new(&genesis_config);

        let tx = system_transaction::transfer(
            &mint_keypair,
            &keypair.pubkey(),
            1,
            genesis_config.hash(),
        );

        let mut tx_invalid_program_index = tx.clone();
        tx_invalid_program_index.message.instructions[0].program_id_index = 42;
        assert_eq!(
            bank.process_transaction(&tx_invalid_program_index),
            Err(TransactionError::SanitizeFailure)
        );

        let mut tx_invalid_account_index = tx;
        tx_invalid_account_index.message.instructions[0].accounts[0] = 42;
        assert_eq!(
            bank.process_transaction(&tx_invalid_account_index),
            Err(TransactionError::SanitizeFailure)
        );
    }

    #[test]
    fn test_bank_pay_to_self() {
        let (genesis_config, mint_keypair) = create_genesis_config(1);
        let key1 = Keypair::new();
        let bank = Bank::new(&genesis_config);

        bank.transfer(1, &mint_keypair, &key1.pubkey()).unwrap();
        assert_eq!(bank.get_balance(&key1.pubkey()), 1);
        let tx = system_transaction::transfer(&key1, &key1.pubkey(), 1, genesis_config.hash());
        let _res = bank.process_transaction(&tx);

        assert_eq!(bank.get_balance(&key1.pubkey()), 1);
        bank.get_signature_status(&tx.signatures[0])
            .unwrap()
            .unwrap();
    }

    fn new_from_parent(parent: &Arc<Bank>) -> Bank {
        Bank::new_from_parent(parent, &Pubkey::default(), parent.slot() + 1)
    }

    /// Verify that the parent's vector is computed correctly
    #[test]
    fn test_bank_parents() {
        let (genesis_config, _) = create_genesis_config(1);
        let parent = Arc::new(Bank::new(&genesis_config));

        let bank = new_from_parent(&parent);
        assert!(Arc::ptr_eq(&bank.parents()[0], &parent));
    }

    /// Verifies that last ids and status cache are correctly referenced from parent
    #[test]
    fn test_bank_parent_duplicate_signature() {
        let (genesis_config, mint_keypair) = create_genesis_config(2);
        let key1 = Keypair::new();
        let parent = Arc::new(Bank::new(&genesis_config));

        let tx =
            system_transaction::transfer(&mint_keypair, &key1.pubkey(), 1, genesis_config.hash());
        assert_eq!(parent.process_transaction(&tx), Ok(()));
        let bank = new_from_parent(&parent);
        assert_eq!(
            bank.process_transaction(&tx),
            Err(TransactionError::DuplicateSignature)
        );
    }

    /// Verifies that last ids and accounts are correctly referenced from parent
    #[test]
    fn test_bank_parent_account_spend() {
        let (genesis_config, mint_keypair) = create_genesis_config(2);
        let key1 = Keypair::new();
        let key2 = Keypair::new();
        let parent = Arc::new(Bank::new(&genesis_config));

        let tx =
            system_transaction::transfer(&mint_keypair, &key1.pubkey(), 1, genesis_config.hash());
        assert_eq!(parent.process_transaction(&tx), Ok(()));
        let bank = new_from_parent(&parent);
        let tx = system_transaction::transfer(&key1, &key2.pubkey(), 1, genesis_config.hash());
        assert_eq!(bank.process_transaction(&tx), Ok(()));
        assert_eq!(parent.get_signature_status(&tx.signatures[0]), None);
    }

    #[test]
    fn test_bank_hash_internal_state() {
        let (genesis_config, mint_keypair) = create_genesis_config(2_000);
        let bank0 = Bank::new(&genesis_config);
        let bank1 = Bank::new(&genesis_config);
        let initial_state = bank0.hash_internal_state();
        assert_eq!(bank1.hash_internal_state(), initial_state);

        let pubkey = Pubkey::new_rand();
        bank0.transfer(1_000, &mint_keypair, &pubkey).unwrap();
        assert_ne!(bank0.hash_internal_state(), initial_state);
        bank1.transfer(1_000, &mint_keypair, &pubkey).unwrap();
        assert_eq!(bank0.hash_internal_state(), bank1.hash_internal_state());

        // Checkpointing should always result in a new state
        let bank2 = new_from_parent(&Arc::new(bank1));
        assert_ne!(bank0.hash_internal_state(), bank2.hash_internal_state());

        let pubkey2 = Pubkey::new_rand();
        info!("transfer 2 {}", pubkey2);
        bank2.transfer(10, &mint_keypair, &pubkey2).unwrap();
        bank2.update_accounts_hash();
        assert!(bank2.verify_bank_hash());
    }

    #[test]
    fn test_bank_hash_internal_state_verify() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(2_000);
        let bank0 = Bank::new(&genesis_config);

        let pubkey = Pubkey::new_rand();
        info!("transfer 0 {} mint: {}", pubkey, mint_keypair.pubkey());
        bank0.transfer(1_000, &mint_keypair, &pubkey).unwrap();

        let bank0_state = bank0.hash_internal_state();
        let bank0 = Arc::new(bank0);
        // Checkpointing should result in a new state while freezing the parent
        let bank2 = Bank::new_from_parent(&bank0, &Pubkey::new_rand(), 1);
        assert_ne!(bank0_state, bank2.hash_internal_state());
        // Checkpointing should modify the checkpoint's state when freezed
        assert_ne!(bank0_state, bank0.hash_internal_state());

        // Checkpointing should never modify the checkpoint's state once frozen
        let bank0_state = bank0.hash_internal_state();
        bank2.update_accounts_hash();
        assert!(bank2.verify_bank_hash());
        let bank3 = Bank::new_from_parent(&bank0, &Pubkey::new_rand(), 2);
        assert_eq!(bank0_state, bank0.hash_internal_state());
        assert!(bank2.verify_bank_hash());
        bank3.update_accounts_hash();
        assert!(bank3.verify_bank_hash());

        let pubkey2 = Pubkey::new_rand();
        info!("transfer 2 {}", pubkey2);
        bank2.transfer(10, &mint_keypair, &pubkey2).unwrap();
        bank2.update_accounts_hash();
        assert!(bank2.verify_bank_hash());
        assert!(bank3.verify_bank_hash());
    }

    #[test]
    #[should_panic(expected = "assertion failed: self.is_frozen()")]
    fn test_verify_hash_unfrozen() {
        let (genesis_config, _mint_keypair) = create_genesis_config(2_000);
        let bank = Bank::new(&genesis_config);
        assert!(bank.verify_hash());
    }

    #[test]
    fn test_verify_snapshot_bank() {
        let pubkey = Pubkey::new_rand();
        let (genesis_config, mint_keypair) = create_genesis_config(2_000);
        let bank = Bank::new(&genesis_config);

        bank.transfer(1_000, &mint_keypair, &pubkey).unwrap();
        bank.freeze();
        bank.update_accounts_hash();
        assert!(bank.verify_snapshot_bank());

        // tamper the bank after freeze!
        bank.increment_signature_count(1);
        assert!(!bank.verify_snapshot_bank());
    }

    // Test that two bank forks with the same accounts should not hash to the same value.
    #[test]
    fn test_bank_hash_internal_state_same_account_different_fork() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(2_000);
        let bank0 = Arc::new(Bank::new(&genesis_config));
        let initial_state = bank0.hash_internal_state();
        let bank1 = Bank::new_from_parent(&bank0, &Pubkey::default(), 1);
        assert_ne!(bank1.hash_internal_state(), initial_state);

        info!("transfer bank1");
        let pubkey = Pubkey::new_rand();
        bank1.transfer(1_000, &mint_keypair, &pubkey).unwrap();
        assert_ne!(bank1.hash_internal_state(), initial_state);

        info!("transfer bank2");
        // bank2 should not hash the same as bank1
        let bank2 = Bank::new_from_parent(&bank0, &Pubkey::default(), 2);
        bank2.transfer(1_000, &mint_keypair, &pubkey).unwrap();
        assert_ne!(bank2.hash_internal_state(), initial_state);
        assert_ne!(bank1.hash_internal_state(), bank2.hash_internal_state());
    }

    #[test]
    fn test_hash_internal_state_genesis() {
        let bank0 = Bank::new(&create_genesis_config(10).0);
        let bank1 = Bank::new(&create_genesis_config(20).0);
        assert_ne!(bank0.hash_internal_state(), bank1.hash_internal_state());
    }

    // See that the order of two transfers does not affect the result
    // of hash_internal_state
    #[test]
    fn test_hash_internal_state_order() {
        let (genesis_config, mint_keypair) = create_genesis_config(100);
        let bank0 = Bank::new(&genesis_config);
        let bank1 = Bank::new(&genesis_config);
        assert_eq!(bank0.hash_internal_state(), bank1.hash_internal_state());
        let key0 = Pubkey::new_rand();
        let key1 = Pubkey::new_rand();
        bank0.transfer(10, &mint_keypair, &key0).unwrap();
        bank0.transfer(20, &mint_keypair, &key1).unwrap();

        bank1.transfer(20, &mint_keypair, &key1).unwrap();
        bank1.transfer(10, &mint_keypair, &key0).unwrap();

        assert_eq!(bank0.hash_internal_state(), bank1.hash_internal_state());
    }

    #[test]
    fn test_hash_internal_state_error() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(100);
        let bank = Bank::new(&genesis_config);
        let key0 = Pubkey::new_rand();
        bank.transfer(10, &mint_keypair, &key0).unwrap();
        let orig = bank.hash_internal_state();

        // Transfer will error but still take a fee
        assert!(bank.transfer(1000, &mint_keypair, &key0).is_err());
        assert_ne!(orig, bank.hash_internal_state());

        let orig = bank.hash_internal_state();
        let empty_keypair = Keypair::new();
        assert!(bank.transfer(1000, &empty_keypair, &key0).is_err());
        assert_eq!(orig, bank.hash_internal_state());
    }

    #[test]
    fn test_bank_hash_internal_state_squash() {
        let collector_id = Pubkey::default();
        let bank0 = Arc::new(Bank::new(&create_genesis_config(10).0));
        let hash0 = bank0.hash_internal_state();
        // save hash0 because new_from_parent
        // updates sysvar entries

        let bank1 = Bank::new_from_parent(&bank0, &collector_id, 1);

        // no delta in bank1, hashes should always update
        assert_ne!(hash0, bank1.hash_internal_state());

        // remove parent
        bank1.squash();
        assert!(bank1.parents().is_empty());
    }

    /// Verifies that last ids and accounts are correctly referenced from parent
    #[test]
    fn test_bank_squash() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(2);
        let key1 = Keypair::new();
        let key2 = Keypair::new();
        let parent = Arc::new(Bank::new(&genesis_config));

        let tx_transfer_mint_to_1 =
            system_transaction::transfer(&mint_keypair, &key1.pubkey(), 1, genesis_config.hash());
        trace!("parent process tx ");
        assert_eq!(parent.process_transaction(&tx_transfer_mint_to_1), Ok(()));
        trace!("done parent process tx ");
        assert_eq!(parent.transaction_count(), 1);
        assert_eq!(
            parent.get_signature_status(&tx_transfer_mint_to_1.signatures[0]),
            Some(Ok(()))
        );

        trace!("new from parent");
        let bank = new_from_parent(&parent);
        trace!("done new from parent");
        assert_eq!(
            bank.get_signature_status(&tx_transfer_mint_to_1.signatures[0]),
            Some(Ok(()))
        );

        assert_eq!(bank.transaction_count(), parent.transaction_count());
        let tx_transfer_1_to_2 =
            system_transaction::transfer(&key1, &key2.pubkey(), 1, genesis_config.hash());
        assert_eq!(bank.process_transaction(&tx_transfer_1_to_2), Ok(()));
        assert_eq!(bank.transaction_count(), 2);
        assert_eq!(parent.transaction_count(), 1);
        assert_eq!(
            parent.get_signature_status(&tx_transfer_1_to_2.signatures[0]),
            None
        );

        for _ in 0..3 {
            // first time these should match what happened above, assert that parents are ok
            assert_eq!(bank.get_balance(&key1.pubkey()), 0);
            assert_eq!(bank.get_account(&key1.pubkey()), None);
            assert_eq!(bank.get_balance(&key2.pubkey()), 1);
            trace!("start");
            assert_eq!(
                bank.get_signature_status(&tx_transfer_mint_to_1.signatures[0]),
                Some(Ok(()))
            );
            assert_eq!(
                bank.get_signature_status(&tx_transfer_1_to_2.signatures[0]),
                Some(Ok(()))
            );

            // works iteration 0, no-ops on iteration 1 and 2
            trace!("SQUASH");
            bank.squash();

            assert_eq!(parent.transaction_count(), 1);
            assert_eq!(bank.transaction_count(), 2);
        }
    }

    #[test]
    fn test_bank_get_account_in_parent_after_squash() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let parent = Arc::new(Bank::new(&genesis_config));

        let key1 = Keypair::new();

        parent.transfer(1, &mint_keypair, &key1.pubkey()).unwrap();
        assert_eq!(parent.get_balance(&key1.pubkey()), 1);
        let bank = new_from_parent(&parent);
        bank.squash();
        assert_eq!(parent.get_balance(&key1.pubkey()), 1);
    }

    #[test]
    fn test_bank_get_account_in_parent_after_squash2() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let bank0 = Arc::new(Bank::new(&genesis_config));

        let key1 = Keypair::new();

        bank0.transfer(1, &mint_keypair, &key1.pubkey()).unwrap();
        assert_eq!(bank0.get_balance(&key1.pubkey()), 1);

        let bank1 = Arc::new(Bank::new_from_parent(&bank0, &Pubkey::default(), 1));
        bank1.transfer(3, &mint_keypair, &key1.pubkey()).unwrap();
        let bank2 = Arc::new(Bank::new_from_parent(&bank0, &Pubkey::default(), 2));
        bank2.transfer(2, &mint_keypair, &key1.pubkey()).unwrap();
        let bank3 = Arc::new(Bank::new_from_parent(&bank1, &Pubkey::default(), 3));
        bank1.squash();

        // This picks up the values from 1 which is the highest root:
        // TODO: if we need to access rooted banks older than this,
        // need to fix the lookup.
        assert_eq!(bank0.get_balance(&key1.pubkey()), 4);
        assert_eq!(bank3.get_balance(&key1.pubkey()), 4);
        assert_eq!(bank2.get_balance(&key1.pubkey()), 3);
        bank3.squash();
        assert_eq!(bank1.get_balance(&key1.pubkey()), 4);

        let bank4 = Arc::new(Bank::new_from_parent(&bank3, &Pubkey::default(), 4));
        bank4.transfer(4, &mint_keypair, &key1.pubkey()).unwrap();
        assert_eq!(bank4.get_balance(&key1.pubkey()), 8);
        assert_eq!(bank3.get_balance(&key1.pubkey()), 4);
        bank4.squash();
        let bank5 = Arc::new(Bank::new_from_parent(&bank4, &Pubkey::default(), 5));
        bank5.squash();
        let bank6 = Arc::new(Bank::new_from_parent(&bank5, &Pubkey::default(), 6));
        bank6.squash();

        // This picks up the values from 4 which is the highest root:
        // TODO: if we need to access rooted banks older than this,
        // need to fix the lookup.
        assert_eq!(bank3.get_balance(&key1.pubkey()), 8);
        assert_eq!(bank2.get_balance(&key1.pubkey()), 8);

        assert_eq!(bank4.get_balance(&key1.pubkey()), 8);
    }

    #[test]
    fn test_bank_get_account_modified_since_parent() {
        let pubkey = Pubkey::new_rand();

        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let bank1 = Arc::new(Bank::new(&genesis_config));
        bank1.transfer(1, &mint_keypair, &pubkey).unwrap();
        let result = bank1.get_account_modified_since_parent(&pubkey);
        assert!(result.is_some());
        let (account, slot) = result.unwrap();
        assert_eq!(account.lamports, 1);
        assert_eq!(slot, 0);

        let bank2 = Arc::new(Bank::new_from_parent(&bank1, &Pubkey::default(), 1));
        assert!(bank2.get_account_modified_since_parent(&pubkey).is_none());
        bank2.transfer(100, &mint_keypair, &pubkey).unwrap();
        let result = bank1.get_account_modified_since_parent(&pubkey);
        assert!(result.is_some());
        let (account, slot) = result.unwrap();
        assert_eq!(account.lamports, 1);
        assert_eq!(slot, 0);
        let result = bank2.get_account_modified_since_parent(&pubkey);
        assert!(result.is_some());
        let (account, slot) = result.unwrap();
        assert_eq!(account.lamports, 101);
        assert_eq!(slot, 1);

        bank1.squash();

        let bank3 = Bank::new_from_parent(&bank2, &Pubkey::default(), 3);
        assert_eq!(None, bank3.get_account_modified_since_parent(&pubkey));
    }

    #[test]
    fn test_bank_update_sysvar_account() {
        use sysvar::clock::Clock;

        let dummy_clock_id = Pubkey::new_rand();
        let (genesis_config, _mint_keypair) = create_genesis_config(500);

        let expected_previous_slot = 3;
        let expected_next_slot = expected_previous_slot + 1;

        // First, initialize the clock sysvar
        let bank1 = Arc::new(Bank::new(&genesis_config));
        bank1.update_sysvar_account(&dummy_clock_id, |optional_account| {
            assert!(optional_account.is_none());
            Clock {
                slot: expected_previous_slot,
                ..Clock::default()
            }
            .create_account(1)
        });
        let current_account = bank1.get_account(&dummy_clock_id).unwrap();
        assert_eq!(
            expected_previous_slot,
            Clock::from_account(&current_account).unwrap().slot
        );

        // Updating should increment the clock's slot
        let bank2 = Arc::new(Bank::new_from_parent(&bank1, &Pubkey::default(), 1));
        bank2.update_sysvar_account(&dummy_clock_id, |optional_account| {
            let slot = Clock::from_account(optional_account.as_ref().unwrap())
                .unwrap()
                .slot
                + 1;

            Clock {
                slot,
                ..Clock::default()
            }
            .create_account(1)
        });
        let current_account = bank2.get_account(&dummy_clock_id).unwrap();
        assert_eq!(
            expected_next_slot,
            Clock::from_account(&current_account).unwrap().slot
        );

        // Updating again should give bank1's sysvar to the closure not bank2's.
        // Thus, assert with same expected_next_slot as previously
        bank2.update_sysvar_account(&dummy_clock_id, |optional_account| {
            let slot = Clock::from_account(optional_account.as_ref().unwrap())
                .unwrap()
                .slot
                + 1;

            Clock {
                slot,
                ..Clock::default()
            }
            .create_account(1)
        });
        let current_account = bank2.get_account(&dummy_clock_id).unwrap();
        assert_eq!(
            expected_next_slot,
            Clock::from_account(&current_account).unwrap().slot
        );
    }

    #[test]
    fn test_bank_epoch_vote_accounts() {
        let leader_pubkey = Pubkey::new_rand();
        let leader_lamports = 3;
        let mut genesis_config =
            create_genesis_config_with_leader(5, &leader_pubkey, leader_lamports).genesis_config;

        // set this up weird, forces future generation, odd mod(), etc.
        //  this says: "vote_accounts for epoch X should be generated at slot index 3 in epoch X-2...
        const SLOTS_PER_EPOCH: u64 = MINIMUM_SLOTS_PER_EPOCH as u64;
        const LEADER_SCHEDULE_SLOT_OFFSET: u64 = SLOTS_PER_EPOCH * 3 - 3;
        // no warmup allows me to do the normal division stuff below
        genesis_config.epoch_schedule =
            EpochSchedule::custom(SLOTS_PER_EPOCH, LEADER_SCHEDULE_SLOT_OFFSET, false);

        let parent = Arc::new(Bank::new(&genesis_config));
        let mut leader_vote_stake: Vec<_> = parent
            .epoch_vote_accounts(0)
            .map(|accounts| {
                accounts
                    .iter()
                    .filter_map(|(pubkey, (stake, account))| {
                        if let Ok(vote_state) = VoteState::deserialize(&account.data) {
                            if vote_state.node_pubkey == leader_pubkey {
                                Some((*pubkey, *stake))
                            } else {
                                None
                            }
                        } else {
                            None
                        }
                    })
                    .collect()
            })
            .unwrap();
        assert_eq!(leader_vote_stake.len(), 1);
        let (leader_vote_account, leader_stake) = leader_vote_stake.pop().unwrap();
        assert!(leader_stake > 0);

        let leader_stake = Stake {
            delegation: Delegation {
                stake: leader_lamports,
                activation_epoch: std::u64::MAX, // bootstrap
                ..Delegation::default()
            },
            ..Stake::default()
        };

        let mut epoch = 1;
        loop {
            if epoch > LEADER_SCHEDULE_SLOT_OFFSET / SLOTS_PER_EPOCH {
                break;
            }
            let vote_accounts = parent.epoch_vote_accounts(epoch);
            assert!(vote_accounts.is_some());

            // epoch_stakes are a snapshot at the leader_schedule_slot_offset boundary
            //   in the prior epoch (0 in this case)
            assert_eq!(
                leader_stake.stake(0, None),
                vote_accounts.unwrap().get(&leader_vote_account).unwrap().0
            );

            epoch += 1;
        }

        // child crosses epoch boundary and is the first slot in the epoch
        let child = Bank::new_from_parent(
            &parent,
            &leader_pubkey,
            SLOTS_PER_EPOCH - (LEADER_SCHEDULE_SLOT_OFFSET % SLOTS_PER_EPOCH),
        );

        assert!(child.epoch_vote_accounts(epoch).is_some());
        assert_eq!(
            leader_stake.stake(child.epoch(), None),
            child
                .epoch_vote_accounts(epoch)
                .unwrap()
                .get(&leader_vote_account)
                .unwrap()
                .0
        );

        // child crosses epoch boundary but isn't the first slot in the epoch, still
        //  makes an epoch stakes snapshot at 1
        let child = Bank::new_from_parent(
            &parent,
            &leader_pubkey,
            SLOTS_PER_EPOCH - (LEADER_SCHEDULE_SLOT_OFFSET % SLOTS_PER_EPOCH) + 1,
        );
        assert!(child.epoch_vote_accounts(epoch).is_some());
        assert_eq!(
            leader_stake.stake(child.epoch(), None),
            child
                .epoch_vote_accounts(epoch)
                .unwrap()
                .get(&leader_vote_account)
                .unwrap()
                .0
        );
    }

    #[test]
    fn test_zero_signatures() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let mut bank = Bank::new(&genesis_config);
        bank.fee_calculator.lamports_per_signature = 2;
        let key = Keypair::new();

        let mut transfer_instruction =
            system_instruction::transfer(&mint_keypair.pubkey(), &key.pubkey(), 0);
        transfer_instruction.accounts[0].is_signer = false;
        let message = Message::new(&[transfer_instruction], None);
        let tx = Transaction::new(&[&Keypair::new(); 0], message, bank.last_blockhash());

        assert_eq!(
            bank.process_transaction(&tx),
            Err(TransactionError::SanitizeFailure)
        );
        assert_eq!(bank.get_balance(&key.pubkey()), 0);
    }

    #[test]
    fn test_bank_get_slots_in_epoch() {
        let (genesis_config, _) = create_genesis_config(500);

        let bank = Bank::new(&genesis_config);

        assert_eq!(bank.get_slots_in_epoch(0), MINIMUM_SLOTS_PER_EPOCH as u64);
        assert_eq!(
            bank.get_slots_in_epoch(2),
            (MINIMUM_SLOTS_PER_EPOCH * 4) as u64
        );
        assert_eq!(
            bank.get_slots_in_epoch(5000),
            genesis_config.epoch_schedule.slots_per_epoch
        );
    }

    #[test]
    fn test_bank_entered_epoch_callback() {
        let (genesis_config, _) = create_genesis_config(500);
        let bank0 = Arc::new(Bank::new(&genesis_config));
        let callback_count = Arc::new(AtomicU64::new(0));

        bank0.set_entered_epoch_callback({
            let callback_count = callback_count.clone();
            //Box::new(move |_bank: &mut Bank| {
            Box::new(move |_| {
                callback_count.fetch_add(1, Ordering::SeqCst);
            })
        });

        let _bank1 =
            Bank::new_from_parent(&bank0, &Pubkey::default(), bank0.get_slots_in_epoch(0) - 1);
        // No callback called while within epoch 0
        assert_eq!(callback_count.load(Ordering::SeqCst), 0);

        let _bank1 = Bank::new_from_parent(&bank0, &Pubkey::default(), bank0.get_slots_in_epoch(0));
        // Callback called as bank1 is in epoch 1
        assert_eq!(callback_count.load(Ordering::SeqCst), 1);

        callback_count.store(0, Ordering::SeqCst);
        let _bank1 = Bank::new_from_parent(
            &bank0,
            &Pubkey::default(),
            std::u64::MAX / bank0.ticks_per_slot - 1,
        );
        // If the new bank jumps ahead multiple epochs the callback is still only called once.
        // This was done to keep the callback implementation simpler as new bank will never jump
        // cross multiple epochs in a real deployment.
        assert_eq!(callback_count.load(Ordering::SeqCst), 1);
    }

    #[test]
    fn test_is_delta_true() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let bank = Arc::new(Bank::new(&genesis_config));
        let key1 = Keypair::new();
        let tx_transfer_mint_to_1 =
            system_transaction::transfer(&mint_keypair, &key1.pubkey(), 1, genesis_config.hash());
        assert_eq!(bank.process_transaction(&tx_transfer_mint_to_1), Ok(()));
        assert_eq!(bank.is_delta.load(Ordering::Relaxed), true);

        let bank1 = new_from_parent(&bank);
        let hash1 = bank1.hash_internal_state();
        assert_eq!(bank1.is_delta.load(Ordering::Relaxed), false);
        assert_ne!(hash1, bank.hash());
        // ticks don't make a bank into a delta or change its state unless a block boundary is crossed
        bank1.register_tick(&Hash::default());
        assert_eq!(bank1.is_delta.load(Ordering::Relaxed), false);
        assert_eq!(bank1.hash_internal_state(), hash1);
    }

    #[test]
    fn test_is_empty() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let bank0 = Arc::new(Bank::new(&genesis_config));
        let key1 = Keypair::new();

        // The zeroth bank is empty becasue there are no transactions
        assert_eq!(bank0.is_empty(), true);

        // Set is_delta to true, bank is no longer empty
        let tx_transfer_mint_to_1 =
            system_transaction::transfer(&mint_keypair, &key1.pubkey(), 1, genesis_config.hash());
        assert_eq!(bank0.process_transaction(&tx_transfer_mint_to_1), Ok(()));
        assert_eq!(bank0.is_empty(), false);
    }

    #[test]
    fn test_bank_inherit_tx_count() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let bank0 = Arc::new(Bank::new(&genesis_config));

        // Bank 1
        let bank1 = Arc::new(Bank::new_from_parent(&bank0, &Pubkey::new_rand(), 1));
        // Bank 2
        let bank2 = Bank::new_from_parent(&bank0, &Pubkey::new_rand(), 2);

        // transfer a token
        assert_eq!(
            bank1.process_transaction(&system_transaction::transfer(
                &mint_keypair,
                &Keypair::new().pubkey(),
                1,
                genesis_config.hash(),
            )),
            Ok(())
        );

        assert_eq!(bank0.transaction_count(), 0);
        assert_eq!(bank2.transaction_count(), 0);
        assert_eq!(bank1.transaction_count(), 1);

        bank1.squash();

        assert_eq!(bank0.transaction_count(), 0);
        assert_eq!(bank2.transaction_count(), 0);
        assert_eq!(bank1.transaction_count(), 1);

        let bank6 = Bank::new_from_parent(&bank1, &Pubkey::new_rand(), 3);
        assert_eq!(bank1.transaction_count(), 1);
        assert_eq!(bank6.transaction_count(), 1);

        bank6.squash();
        assert_eq!(bank6.transaction_count(), 1);
    }

    #[test]
    fn test_bank_inherit_fee_rate_governor() {
        let (mut genesis_config, _mint_keypair) = create_genesis_config(500);
        genesis_config
            .fee_rate_governor
            .target_lamports_per_signature = 123;

        let bank0 = Arc::new(Bank::new(&genesis_config));
        let bank1 = Arc::new(new_from_parent(&bank0));
        assert_eq!(
            bank0.fee_rate_governor.target_lamports_per_signature / 2,
            bank1
                .fee_rate_governor
                .create_fee_calculator()
                .lamports_per_signature
        );
    }

    #[test]
    fn test_bank_vote_accounts() {
        let GenesisConfigInfo {
            genesis_config,
            mint_keypair,
            ..
        } = create_genesis_config_with_leader(500, &Pubkey::new_rand(), 1);
        let bank = Arc::new(Bank::new(&genesis_config));

        let vote_accounts = bank.vote_accounts();
        assert_eq!(vote_accounts.len(), 1); // bootstrap validator has
                                            // to have a vote account

        let vote_keypair = Keypair::new();
        let instructions = vote_instruction::create_account(
            &mint_keypair.pubkey(),
            &vote_keypair.pubkey(),
            &VoteInit {
                node_pubkey: mint_keypair.pubkey(),
                authorized_voter: vote_keypair.pubkey(),
                authorized_withdrawer: vote_keypair.pubkey(),
                commission: 0,
            },
            10,
        );

        let message = Message::new(&instructions, Some(&mint_keypair.pubkey()));
        let transaction = Transaction::new(
            &[&mint_keypair, &vote_keypair],
            message,
            bank.last_blockhash(),
        );

        bank.process_transaction(&transaction).unwrap();

        let vote_accounts = bank.vote_accounts();

        assert_eq!(vote_accounts.len(), 2);

        assert!(vote_accounts.get(&vote_keypair.pubkey()).is_some());

        assert!(bank.withdraw(&vote_keypair.pubkey(), 10).is_ok());

        let vote_accounts = bank.vote_accounts();

        assert_eq!(vote_accounts.len(), 1);
    }

    #[test]
    fn test_bank_stake_delegations() {
        let GenesisConfigInfo {
            genesis_config,
            mint_keypair,
            ..
        } = create_genesis_config_with_leader(500, &Pubkey::new_rand(), 1);
        let bank = Arc::new(Bank::new(&genesis_config));

        let stake_delegations = bank.stake_delegations();
        assert_eq!(stake_delegations.len(), 1); // bootstrap validator has
                                                // to have a stake delegation

        let vote_keypair = Keypair::new();
        let mut instructions = vote_instruction::create_account(
            &mint_keypair.pubkey(),
            &vote_keypair.pubkey(),
            &VoteInit {
                node_pubkey: mint_keypair.pubkey(),
                authorized_voter: vote_keypair.pubkey(),
                authorized_withdrawer: vote_keypair.pubkey(),
                commission: 0,
            },
            10,
        );

        let stake_keypair = Keypair::new();
        instructions.extend(stake_instruction::create_account_and_delegate_stake(
            &mint_keypair.pubkey(),
            &stake_keypair.pubkey(),
            &vote_keypair.pubkey(),
            &Authorized::auto(&stake_keypair.pubkey()),
            &Lockup::default(),
            10,
        ));

        let message = Message::new(&instructions, Some(&mint_keypair.pubkey()));
        let transaction = Transaction::new(
            &[&mint_keypair, &vote_keypair, &stake_keypair],
            message,
            bank.last_blockhash(),
        );

        bank.process_transaction(&transaction).unwrap();

        let stake_delegations = bank.stake_delegations();
        assert_eq!(stake_delegations.len(), 2);
        assert!(stake_delegations.get(&stake_keypair.pubkey()).is_some());
    }

    #[test]
    fn test_bank_fees_account() {
        let (mut genesis_config, _) = create_genesis_config(500);
        genesis_config.fee_rate_governor = FeeRateGovernor::new(12345, 0);
        let bank = Arc::new(Bank::new(&genesis_config));

        let fees_account = bank.get_account(&sysvar::fees::id()).unwrap();
        let fees = Fees::from_account(&fees_account).unwrap();
        assert_eq!(
            bank.fee_calculator.lamports_per_signature,
            fees.fee_calculator.lamports_per_signature
        );
        assert_eq!(fees.fee_calculator.lamports_per_signature, 12345);
    }

    #[test]
    fn test_is_delta_with_no_committables() {
        let (genesis_config, mint_keypair) = create_genesis_config(8000);
        let bank = Bank::new(&genesis_config);
        bank.is_delta.store(false, Ordering::Relaxed);

        let keypair1 = Keypair::new();
        let keypair2 = Keypair::new();
        let fail_tx =
            system_transaction::transfer(&keypair1, &keypair2.pubkey(), 1, bank.last_blockhash());

        // Should fail with TransactionError::AccountNotFound, which means
        // the account which this tx operated on will not be committed. Thus
        // the bank is_delta should still be false
        assert_eq!(
            bank.process_transaction(&fail_tx),
            Err(TransactionError::AccountNotFound)
        );

        // Check the bank is_delta is still false
        assert!(!bank.is_delta.load(Ordering::Relaxed));

        // Should fail with InstructionError, but InstructionErrors are committable,
        // so is_delta should be true
        assert_eq!(
            bank.transfer(10_001, &mint_keypair, &Pubkey::new_rand()),
            Err(TransactionError::InstructionError(
                0,
                InstructionError::new_result_with_negative_lamports(),
            ))
        );

        assert!(bank.is_delta.load(Ordering::Relaxed));
    }

    #[test]
    fn test_bank_get_program_accounts() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let parent = Arc::new(Bank::new(&genesis_config));
        parent.lazy_rent_collection.store(true, Ordering::Relaxed);

        let genesis_accounts: Vec<_> = parent.get_program_accounts(None);
        assert!(
            genesis_accounts
                .iter()
                .any(|(pubkey, _)| *pubkey == mint_keypair.pubkey()),
            "mint pubkey not found"
        );
        assert!(
            genesis_accounts
                .iter()
                .any(|(pubkey, _)| solana_sdk::sysvar::is_sysvar_id(pubkey)),
            "no sysvars found"
        );

        let bank0 = Arc::new(new_from_parent(&parent));
        let pubkey0 = Pubkey::new_rand();
        let program_id = Pubkey::new(&[2; 32]);
        let account0 = Account::new(1, 0, &program_id);
        bank0.store_account(&pubkey0, &account0);

        assert_eq!(
            bank0.get_program_accounts_modified_since_parent(&program_id),
            vec![(pubkey0, account0.clone())]
        );

        let bank1 = Arc::new(new_from_parent(&bank0));
        bank1.squash();
        assert_eq!(
            bank0.get_program_accounts(Some(&program_id)),
            vec![(pubkey0, account0.clone())]
        );
        assert_eq!(
            bank1.get_program_accounts(Some(&program_id)),
            vec![(pubkey0, account0)]
        );
        assert_eq!(
            bank1.get_program_accounts_modified_since_parent(&program_id),
            vec![]
        );

        let bank2 = Arc::new(new_from_parent(&bank1));
        let pubkey1 = Pubkey::new_rand();
        let account1 = Account::new(3, 0, &program_id);
        bank2.store_account(&pubkey1, &account1);
        // Accounts with 0 lamports should be filtered out by Accounts::load_by_program()
        let pubkey2 = Pubkey::new_rand();
        let account2 = Account::new(0, 0, &program_id);
        bank2.store_account(&pubkey2, &account2);

        let bank3 = Arc::new(new_from_parent(&bank2));
        bank3.squash();
        assert_eq!(bank1.get_program_accounts(Some(&program_id)).len(), 2);
        assert_eq!(bank3.get_program_accounts(Some(&program_id)).len(), 2);
    }

    #[test]
    fn test_status_cache_ancestors() {
        let (genesis_config, _mint_keypair) = create_genesis_config(500);
        let parent = Arc::new(Bank::new(&genesis_config));
        let bank1 = Arc::new(new_from_parent(&parent));
        let mut bank = bank1;
        for _ in 0..MAX_CACHE_ENTRIES * 2 {
            bank = Arc::new(new_from_parent(&bank));
            bank.squash();
        }

        let bank = new_from_parent(&bank);
        assert_eq!(
            bank.status_cache_ancestors(),
            (bank.slot() - MAX_CACHE_ENTRIES as u64..=bank.slot()).collect::<Vec<_>>()
        );
    }

    #[test]
    fn test_add_builtin_program() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let mut bank = Bank::new(&genesis_config);

        fn mock_vote_program_id() -> Pubkey {
            Pubkey::new(&[42u8; 32])
        }
        fn mock_vote_processor(
            program_id: &Pubkey,
            _keyed_accounts: &[KeyedAccount],
            _instruction_data: &[u8],
        ) -> std::result::Result<(), InstructionError> {
            if mock_vote_program_id() != *program_id {
                return Err(InstructionError::IncorrectProgramId);
            }
            Err(InstructionError::Custom(42))
        }

        assert!(bank.get_account(&mock_vote_program_id()).is_none());
        bank.add_builtin_program(
            "mock_vote_program",
            mock_vote_program_id(),
            mock_vote_processor,
        );
        assert!(bank.get_account(&mock_vote_program_id()).is_some());

        let mock_account = Keypair::new();
        let mock_validator_identity = Keypair::new();
        let mut instructions = vote_instruction::create_account(
            &mint_keypair.pubkey(),
            &mock_account.pubkey(),
            &VoteInit {
                node_pubkey: mock_validator_identity.pubkey(),
                ..VoteInit::default()
            },
            1,
        );
        instructions[1].program_id = mock_vote_program_id();

        let message = Message::new(&instructions, Some(&mint_keypair.pubkey()));
        let transaction = Transaction::new(
            &[&mint_keypair, &mock_account, &mock_validator_identity],
            message,
            bank.last_blockhash(),
        );

        assert_eq!(
            bank.process_transaction(&transaction),
            Err(TransactionError::InstructionError(
                1,
                InstructionError::Custom(42)
            ))
        );
    }

    #[test]
    fn test_add_duplicate_static_program() {
        let GenesisConfigInfo {
            genesis_config,
            mint_keypair,
            ..
        } = create_genesis_config_with_leader(500, &Pubkey::new_rand(), 0);
        let mut bank = Bank::new(&genesis_config);

        fn mock_vote_processor(
            _pubkey: &Pubkey,
            _ka: &[KeyedAccount],
            _data: &[u8],
        ) -> std::result::Result<(), InstructionError> {
            Err(InstructionError::Custom(42))
        }

        let mock_account = Keypair::new();
        let mock_validator_identity = Keypair::new();
        let instructions = vote_instruction::create_account(
            &mint_keypair.pubkey(),
            &mock_account.pubkey(),
            &VoteInit {
                node_pubkey: mock_validator_identity.pubkey(),
                ..VoteInit::default()
            },
            1,
        );

        let message = Message::new(&instructions, Some(&mint_keypair.pubkey()));
        let transaction = Transaction::new(
            &[&mint_keypair, &mock_account, &mock_validator_identity],
            message,
            bank.last_blockhash(),
        );

        let vote_loader_account = bank.get_account(&solana_vote_program::id()).unwrap();
        bank.add_builtin_program(
            "solana_vote_program",
            solana_vote_program::id(),
            mock_vote_processor,
        );
        let new_vote_loader_account = bank.get_account(&solana_vote_program::id()).unwrap();
        // Vote loader account should not be updated since it was included in the genesis config.
        assert_eq!(vote_loader_account.data, new_vote_loader_account.data);
        assert_eq!(
            bank.process_transaction(&transaction),
            Err(TransactionError::InstructionError(
                1,
                InstructionError::Custom(42)
            ))
        );
    }

    #[test]
    #[should_panic]
    fn test_add_instruction_processor_for_invalid_account() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let mut bank = Bank::new(&genesis_config);

        fn mock_ix_processor(
            _pubkey: &Pubkey,
            _ka: &[KeyedAccount],
            _data: &[u8],
        ) -> std::result::Result<(), InstructionError> {
            Err(InstructionError::Custom(42))
        }

        // Non-native loader accounts can not be used for instruction processing
        bank.add_builtin_program("mock_program", mint_keypair.pubkey(), mock_ix_processor);
    }
    #[test]
    fn test_recent_blockhashes_sysvar() {
        let (genesis_config, _mint_keypair) = create_genesis_config(500);
        let mut bank = Arc::new(Bank::new(&genesis_config));
        for i in 1..5 {
            let bhq_account = bank.get_account(&sysvar::recent_blockhashes::id()).unwrap();
            let recent_blockhashes =
                sysvar::recent_blockhashes::RecentBlockhashes::from_account(&bhq_account).unwrap();
            // Check length
            assert_eq!(recent_blockhashes.len(), i);
            let most_recent_hash = recent_blockhashes.iter().next().unwrap().blockhash;
            // Check order
            assert_eq!(Some(true), bank.check_hash_age(&most_recent_hash, 0));
            goto_end_of_slot(Arc::get_mut(&mut bank).unwrap());
            bank = Arc::new(new_from_parent(&bank));
        }
    }

    #[test]
    fn test_blockhash_queue_sysvar_consistency() {
        let (genesis_config, _mint_keypair) = create_genesis_config(100_000);
        let mut bank = Arc::new(Bank::new(&genesis_config));
        goto_end_of_slot(Arc::get_mut(&mut bank).unwrap());

        let bhq_account = bank.get_account(&sysvar::recent_blockhashes::id()).unwrap();
        let recent_blockhashes =
            sysvar::recent_blockhashes::RecentBlockhashes::from_account(&bhq_account).unwrap();

        let sysvar_recent_blockhash = recent_blockhashes[0].blockhash;
        let bank_last_blockhash = bank.last_blockhash();
        assert_eq!(sysvar_recent_blockhash, bank_last_blockhash);
    }

    #[test]
    fn test_bank_inherit_last_vote_sync() {
        let (genesis_config, _) = create_genesis_config(500);
        let bank0 = Arc::new(Bank::new(&genesis_config));
        let last_ts = bank0.last_vote_sync.load(Ordering::Relaxed);
        assert_eq!(last_ts, 0);
        bank0.last_vote_sync.store(1, Ordering::Relaxed);
        let bank1 =
            Bank::new_from_parent(&bank0, &Pubkey::default(), bank0.get_slots_in_epoch(0) - 1);
        let last_ts = bank1.last_vote_sync.load(Ordering::Relaxed);
        assert_eq!(last_ts, 1);
    }

    #[test]
    fn test_hash_internal_state_unchanged() {
        let (genesis_config, _) = create_genesis_config(500);
        let bank0 = Arc::new(Bank::new(&genesis_config));
        bank0.freeze();
        let bank0_hash = bank0.hash();
        let bank1 = Bank::new_from_parent(&bank0, &Pubkey::default(), 1);
        bank1.freeze();
        let bank1_hash = bank1.hash();
        // Checkpointing should always result in a new state
        assert_ne!(bank0_hash, bank1_hash);
    }

    #[test]
    fn test_ticks_change_state() {
        let (genesis_config, _) = create_genesis_config(500);
        let bank = Arc::new(Bank::new(&genesis_config));
        let bank1 = new_from_parent(&bank);
        let hash1 = bank1.hash_internal_state();
        // ticks don't change its state unless a block boundary is crossed
        for _ in 0..genesis_config.ticks_per_slot {
            assert_eq!(bank1.hash_internal_state(), hash1);
            bank1.register_tick(&Hash::default());
        }
        assert_ne!(bank1.hash_internal_state(), hash1);
    }

    #[ignore]
    #[test]
    fn test_banks_leak() {
        fn add_lotsa_stake_accounts(genesis_config: &mut GenesisConfig) {
            const LOTSA: usize = 4_096;

            (0..LOTSA).for_each(|_| {
                let pubkey = Pubkey::new_rand();
                genesis_config.add_account(
                    pubkey,
                    solana_stake_program::stake_state::create_lockup_stake_account(
                        &Authorized::auto(&pubkey),
                        &Lockup::default(),
                        &Rent::default(),
                        50_000_000,
                    ),
                );
            });
        }
        solana_logger::setup();
        let (mut genesis_config, _) = create_genesis_config(100_000_000_000_000);
        add_lotsa_stake_accounts(&mut genesis_config);
        let mut bank = std::sync::Arc::new(Bank::new(&genesis_config));
        let mut num_banks = 0;
        let pid = std::process::id();
        #[cfg(not(target_os = "linux"))]
        error!(
            "\nYou can run this to watch RAM:\n   while read -p 'banks: '; do echo $(( $(ps -o vsize= -p {})/$REPLY));done", pid
        );
        loop {
            num_banks += 1;
            bank = std::sync::Arc::new(new_from_parent(&bank));
            if num_banks % 100 == 0 {
                #[cfg(target_os = "linux")]
                {
                    let pages_consumed = std::fs::read_to_string(format!("/proc/{}/statm", pid))
                        .unwrap()
                        .split_whitespace()
                        .next()
                        .unwrap()
                        .parse::<usize>()
                        .unwrap();
                    error!(
                        "at {} banks: {} mem or {}kB/bank",
                        num_banks,
                        pages_consumed * 4096,
                        (pages_consumed * 4) / num_banks
                    );
                }
                #[cfg(not(target_os = "linux"))]
                {
                    error!("{} banks, sleeping for 5 sec", num_banks);
                    std::thread::sleep(Duration::new(5, 0));
                }
            }
        }
    }

    fn get_nonce_account(bank: &Bank, nonce_pubkey: &Pubkey) -> Option<Hash> {
        bank.get_account(&nonce_pubkey).and_then(|acc| {
            let state =
                StateMut::<nonce::state::Versions>::state(&acc).map(|v| v.convert_to_current());
            match state {
                Ok(nonce::State::Initialized(ref data)) => Some(data.blockhash),
                _ => None,
            }
        })
    }

    fn nonce_setup(
        bank: &mut Arc<Bank>,
        mint_keypair: &Keypair,
        custodian_lamports: u64,
        nonce_lamports: u64,
        nonce_authority: Option<Pubkey>,
    ) -> Result<(Keypair, Keypair)> {
        let custodian_keypair = Keypair::new();
        let nonce_keypair = Keypair::new();
        /* Setup accounts */
        let mut setup_ixs = vec![system_instruction::transfer(
            &mint_keypair.pubkey(),
            &custodian_keypair.pubkey(),
            custodian_lamports,
        )];
        let nonce_authority = nonce_authority.unwrap_or_else(|| nonce_keypair.pubkey());
        setup_ixs.extend_from_slice(&system_instruction::create_nonce_account(
            &custodian_keypair.pubkey(),
            &nonce_keypair.pubkey(),
            &nonce_authority,
            nonce_lamports,
        ));
        let message = Message::new(&setup_ixs, Some(&mint_keypair.pubkey()));
        let setup_tx = Transaction::new(
            &[mint_keypair, &custodian_keypair, &nonce_keypair],
            message,
            bank.last_blockhash(),
        );
        bank.process_transaction(&setup_tx)?;
        Ok((custodian_keypair, nonce_keypair))
    }

    fn setup_nonce_with_bank<F>(
        supply_lamports: u64,
        mut genesis_cfg_fn: F,
        custodian_lamports: u64,
        nonce_lamports: u64,
        nonce_authority: Option<Pubkey>,
    ) -> Result<(Arc<Bank>, Keypair, Keypair, Keypair)>
    where
        F: FnMut(&mut GenesisConfig),
    {
        let (mut genesis_config, mint_keypair) = create_genesis_config(supply_lamports);
        genesis_config.rent.lamports_per_byte_year = 0;
        genesis_cfg_fn(&mut genesis_config);
        let mut bank = Arc::new(Bank::new(&genesis_config));

        // Banks 0 and 1 have no fees, wait two blocks before
        // initializing our nonce accounts
        for _ in 0..2 {
            goto_end_of_slot(Arc::get_mut(&mut bank).unwrap());
            bank = Arc::new(new_from_parent(&bank));
        }

        let (custodian_keypair, nonce_keypair) = nonce_setup(
            &mut bank,
            &mint_keypair,
            custodian_lamports,
            nonce_lamports,
            nonce_authority,
        )?;
        Ok((bank, mint_keypair, custodian_keypair, nonce_keypair))
    }

    #[test]
    fn test_check_tx_durable_nonce_ok() {
        let (bank, _mint_keypair, custodian_keypair, nonce_keypair) =
            setup_nonce_with_bank(10_000_000, |_| {}, 5_000_000, 250_000, None).unwrap();
        let custodian_pubkey = custodian_keypair.pubkey();
        let nonce_pubkey = nonce_keypair.pubkey();

        let nonce_hash = get_nonce_account(&bank, &nonce_pubkey).unwrap();
        let tx = Transaction::new_signed_with_payer(
            &[
                system_instruction::advance_nonce_account(&nonce_pubkey, &nonce_pubkey),
                system_instruction::transfer(&custodian_pubkey, &nonce_pubkey, 100_000),
            ],
            Some(&custodian_pubkey),
            &[&custodian_keypair, &nonce_keypair],
            nonce_hash,
        );
        let nonce_account = bank.get_account(&nonce_pubkey).unwrap();
        assert_eq!(
            bank.check_tx_durable_nonce(&tx),
            Some((nonce_pubkey, nonce_account))
        );
    }

    #[test]
    fn test_check_tx_durable_nonce_not_durable_nonce_fail() {
        let (bank, _mint_keypair, custodian_keypair, nonce_keypair) =
            setup_nonce_with_bank(10_000_000, |_| {}, 5_000_000, 250_000, None).unwrap();
        let custodian_pubkey = custodian_keypair.pubkey();
        let nonce_pubkey = nonce_keypair.pubkey();

        let nonce_hash = get_nonce_account(&bank, &nonce_pubkey).unwrap();
        let tx = Transaction::new_signed_with_payer(
            &[
                system_instruction::transfer(&custodian_pubkey, &nonce_pubkey, 100_000),
                system_instruction::advance_nonce_account(&nonce_pubkey, &nonce_pubkey),
            ],
            Some(&custodian_pubkey),
            &[&custodian_keypair, &nonce_keypair],
            nonce_hash,
        );
        assert!(bank.check_tx_durable_nonce(&tx).is_none());
    }

    #[test]
    fn test_check_tx_durable_nonce_missing_ix_pubkey_fail() {
        let (bank, _mint_keypair, custodian_keypair, nonce_keypair) =
            setup_nonce_with_bank(10_000_000, |_| {}, 5_000_000, 250_000, None).unwrap();
        let custodian_pubkey = custodian_keypair.pubkey();
        let nonce_pubkey = nonce_keypair.pubkey();

        let nonce_hash = get_nonce_account(&bank, &nonce_pubkey).unwrap();
        let mut tx = Transaction::new_signed_with_payer(
            &[
                system_instruction::advance_nonce_account(&nonce_pubkey, &nonce_pubkey),
                system_instruction::transfer(&custodian_pubkey, &nonce_pubkey, 100_000),
            ],
            Some(&custodian_pubkey),
            &[&custodian_keypair, &nonce_keypair],
            nonce_hash,
        );
        tx.message.instructions[0].accounts.clear();
        assert!(bank.check_tx_durable_nonce(&tx).is_none());
    }

    #[test]
    fn test_check_tx_durable_nonce_nonce_acc_does_not_exist_fail() {
        let (bank, _mint_keypair, custodian_keypair, nonce_keypair) =
            setup_nonce_with_bank(10_000_000, |_| {}, 5_000_000, 250_000, None).unwrap();
        let custodian_pubkey = custodian_keypair.pubkey();
        let nonce_pubkey = nonce_keypair.pubkey();
        let missing_keypair = Keypair::new();
        let missing_pubkey = missing_keypair.pubkey();

        let nonce_hash = get_nonce_account(&bank, &nonce_pubkey).unwrap();
        let tx = Transaction::new_signed_with_payer(
            &[
                system_instruction::advance_nonce_account(&missing_pubkey, &nonce_pubkey),
                system_instruction::transfer(&custodian_pubkey, &nonce_pubkey, 100_000),
            ],
            Some(&custodian_pubkey),
            &[&custodian_keypair, &nonce_keypair],
            nonce_hash,
        );
        assert!(bank.check_tx_durable_nonce(&tx).is_none());
    }

    #[test]
    fn test_check_tx_durable_nonce_bad_tx_hash_fail() {
        let (bank, _mint_keypair, custodian_keypair, nonce_keypair) =
            setup_nonce_with_bank(10_000_000, |_| {}, 5_000_000, 250_000, None).unwrap();
        let custodian_pubkey = custodian_keypair.pubkey();
        let nonce_pubkey = nonce_keypair.pubkey();

        let tx = Transaction::new_signed_with_payer(
            &[
                system_instruction::advance_nonce_account(&nonce_pubkey, &nonce_pubkey),
                system_instruction::transfer(&custodian_pubkey, &nonce_pubkey, 100_000),
            ],
            Some(&custodian_pubkey),
            &[&custodian_keypair, &nonce_keypair],
            Hash::default(),
        );
        assert!(bank.check_tx_durable_nonce(&tx).is_none());
    }

    #[test]
    fn test_assign_from_nonce_account_fail() {
        let (genesis_config, _mint_keypair) = create_genesis_config(100_000_000);
        let bank = Arc::new(Bank::new(&genesis_config));
        let nonce = Keypair::new();
        let nonce_account = Account::new_data(
            42_424_242,
            &nonce::state::Versions::new_current(nonce::State::Initialized(
                nonce::state::Data::default(),
            )),
            &system_program::id(),
        )
        .unwrap();
        let blockhash = bank.last_blockhash();
        bank.store_account(&nonce.pubkey(), &nonce_account);

        let ix = system_instruction::assign(&nonce.pubkey(), &Pubkey::new(&[9u8; 32]));
        let message = Message::new(&[ix], Some(&nonce.pubkey()));
        let tx = Transaction::new(&[&nonce], message, blockhash);

        let expect = Err(TransactionError::InstructionError(
            0,
            InstructionError::ModifiedProgramId,
        ));
        assert_eq!(bank.process_transaction(&tx), expect);
    }

    #[test]
    fn test_durable_nonce_transaction() {
        let (mut bank, _mint_keypair, custodian_keypair, nonce_keypair) =
            setup_nonce_with_bank(10_000_000, |_| {}, 5_000_000, 250_000, None).unwrap();
        let alice_keypair = Keypair::new();
        let alice_pubkey = alice_keypair.pubkey();
        let custodian_pubkey = custodian_keypair.pubkey();
        let nonce_pubkey = nonce_keypair.pubkey();

        assert_eq!(bank.get_balance(&custodian_pubkey), 4_750_000);
        assert_eq!(bank.get_balance(&nonce_pubkey), 250_000);

        /* Grab the hash stored in the nonce account */
        let nonce_hash = get_nonce_account(&bank, &nonce_pubkey).unwrap();

        /* Kick nonce hash off the blockhash_queue */
        for _ in 0..MAX_RECENT_BLOCKHASHES + 1 {
            goto_end_of_slot(Arc::get_mut(&mut bank).unwrap());
            bank = Arc::new(new_from_parent(&bank));
        }

        /* Expect a non-Durable Nonce transfer to fail */
        assert_eq!(
            bank.process_transaction(&system_transaction::transfer(
                &custodian_keypair,
                &alice_pubkey,
                100_000,
                nonce_hash
            ),),
            Err(TransactionError::BlockhashNotFound),
        );
        /* Check fee not charged */
        assert_eq!(bank.get_balance(&custodian_pubkey), 4_750_000);

        /* Durable Nonce transfer */
        let durable_tx = Transaction::new_signed_with_payer(
            &[
                system_instruction::advance_nonce_account(&nonce_pubkey, &nonce_pubkey),
                system_instruction::transfer(&custodian_pubkey, &alice_pubkey, 100_000),
            ],
            Some(&custodian_pubkey),
            &[&custodian_keypair, &nonce_keypair],
            nonce_hash,
        );
        assert_eq!(bank.process_transaction(&durable_tx), Ok(()));

        /* Check balances */
        assert_eq!(bank.get_balance(&custodian_pubkey), 4_640_000);
        assert_eq!(bank.get_balance(&nonce_pubkey), 250_000);
        assert_eq!(bank.get_balance(&alice_pubkey), 100_000);

        /* Confirm stored nonce has advanced */
        let new_nonce = get_nonce_account(&bank, &nonce_pubkey).unwrap();
        assert_ne!(nonce_hash, new_nonce);

        /* Durable Nonce re-use fails */
        let durable_tx = Transaction::new_signed_with_payer(
            &[
                system_instruction::advance_nonce_account(&nonce_pubkey, &nonce_pubkey),
                system_instruction::transfer(&custodian_pubkey, &alice_pubkey, 100_000),
            ],
            Some(&custodian_pubkey),
            &[&custodian_keypair, &nonce_keypair],
            nonce_hash,
        );
        assert_eq!(
            bank.process_transaction(&durable_tx),
            Err(TransactionError::BlockhashNotFound)
        );
        /* Check fee not charged and nonce not advanced */
        assert_eq!(bank.get_balance(&custodian_pubkey), 4_640_000);
        assert_eq!(new_nonce, get_nonce_account(&bank, &nonce_pubkey).unwrap());

        let nonce_hash = new_nonce;

        /* Kick nonce hash off the blockhash_queue */
        for _ in 0..MAX_RECENT_BLOCKHASHES + 1 {
            goto_end_of_slot(Arc::get_mut(&mut bank).unwrap());
            bank = Arc::new(new_from_parent(&bank));
        }

        let durable_tx = Transaction::new_signed_with_payer(
            &[
                system_instruction::advance_nonce_account(&nonce_pubkey, &nonce_pubkey),
                system_instruction::transfer(&custodian_pubkey, &alice_pubkey, 100_000_000),
            ],
            Some(&custodian_pubkey),
            &[&custodian_keypair, &nonce_keypair],
            nonce_hash,
        );
        assert_eq!(
            bank.process_transaction(&durable_tx),
            Err(TransactionError::InstructionError(
                1,
                system_instruction::SystemError::ResultWithNegativeLamports.into()
            ))
        );
        /* Check fee charged and nonce has advanced */
        assert_eq!(bank.get_balance(&custodian_pubkey), 4_630_000);
        assert_ne!(nonce_hash, get_nonce_account(&bank, &nonce_pubkey).unwrap());
        /* Confirm replaying a TX that failed with InstructionError::* now
         * fails with TransactionError::BlockhashNotFound
         */
        assert_eq!(
            bank.process_transaction(&durable_tx),
            Err(TransactionError::BlockhashNotFound),
        );
    }

    #[test]
    fn test_nonce_fee_calculator_updates() {
        let (mut genesis_config, mint_keypair) = create_genesis_config(1_000_000);
        genesis_config.rent.lamports_per_byte_year = 0;
        let mut bank = Arc::new(Bank::new(&genesis_config));

        // Deliberately use bank 0 to initialize nonce account, so that nonce account fee_calculator indicates 0 fees
        let (custodian_keypair, nonce_keypair) =
            nonce_setup(&mut bank, &mint_keypair, 500_000, 100_000, None).unwrap();
        let custodian_pubkey = custodian_keypair.pubkey();
        let nonce_pubkey = nonce_keypair.pubkey();

        // Grab the hash and fee_calculator stored in the nonce account
        let (stored_nonce_hash, stored_fee_calculator) = bank
            .get_account(&nonce_pubkey)
            .and_then(|acc| {
                let state =
                    StateMut::<nonce::state::Versions>::state(&acc).map(|v| v.convert_to_current());
                match state {
                    Ok(nonce::State::Initialized(ref data)) => {
                        Some((data.blockhash, data.fee_calculator.clone()))
                    }
                    _ => None,
                }
            })
            .unwrap();

        // Kick nonce hash off the blockhash_queue
        for _ in 0..MAX_RECENT_BLOCKHASHES + 1 {
            goto_end_of_slot(Arc::get_mut(&mut bank).unwrap());
            bank = Arc::new(new_from_parent(&bank));
        }

        // Durable Nonce transfer
        let nonce_tx = Transaction::new_signed_with_payer(
            &[
                system_instruction::advance_nonce_account(&nonce_pubkey, &nonce_pubkey),
                system_instruction::transfer(&custodian_pubkey, &Pubkey::new_rand(), 100_000),
            ],
            Some(&custodian_pubkey),
            &[&custodian_keypair, &nonce_keypair],
            stored_nonce_hash,
        );
        bank.process_transaction(&nonce_tx).unwrap();

        // Grab the new hash and fee_calculator; both should be updated
        let (nonce_hash, fee_calculator) = bank
            .get_account(&nonce_pubkey)
            .and_then(|acc| {
                let state =
                    StateMut::<nonce::state::Versions>::state(&acc).map(|v| v.convert_to_current());
                match state {
                    Ok(nonce::State::Initialized(ref data)) => {
                        Some((data.blockhash, data.fee_calculator.clone()))
                    }
                    _ => None,
                }
            })
            .unwrap();

        assert_ne!(stored_nonce_hash, nonce_hash);
        assert_ne!(stored_fee_calculator, fee_calculator);
    }

    #[test]
    fn test_collect_balances() {
        let (genesis_config, _mint_keypair) = create_genesis_config(500);
        let parent = Arc::new(Bank::new(&genesis_config));
        let bank0 = Arc::new(new_from_parent(&parent));

        let keypair = Keypair::new();
        let pubkey0 = Pubkey::new_rand();
        let pubkey1 = Pubkey::new_rand();
        let program_id = Pubkey::new(&[2; 32]);
        let keypair_account = Account::new(8, 0, &program_id);
        let account0 = Account::new(11, 0, &program_id);
        let program_account = Account::new(1, 10, &Pubkey::default());
        bank0.store_account(&keypair.pubkey(), &keypair_account);
        bank0.store_account(&pubkey0, &account0);
        bank0.store_account(&program_id, &program_account);

        let instructions = vec![CompiledInstruction::new(1, &(), vec![0])];
        let tx0 = Transaction::new_with_compiled_instructions(
            &[&keypair],
            &[pubkey0],
            Hash::default(),
            vec![program_id],
            instructions,
        );
        let instructions = vec![CompiledInstruction::new(1, &(), vec![0])];
        let tx1 = Transaction::new_with_compiled_instructions(
            &[&keypair],
            &[pubkey1],
            Hash::default(),
            vec![program_id],
            instructions,
        );
        let txs = vec![tx0, tx1];
        let iteration_order: Vec<usize> = vec![0, 1];
        let batch = bank0.prepare_batch(&txs, Some(iteration_order));
        let balances = bank0.collect_balances(&batch);
        assert_eq!(balances.len(), 2);
        assert_eq!(balances[0], vec![8, 11, 1]);
        assert_eq!(balances[1], vec![8, 0, 1]);

        let iteration_order: Vec<usize> = vec![1, 0];
        let batch = bank0.prepare_batch(&txs, Some(iteration_order));
        let balances = bank0.collect_balances(&batch);
        assert_eq!(balances.len(), 2);
        assert_eq!(balances[0], vec![8, 0, 1]);
        assert_eq!(balances[1], vec![8, 11, 1]);
    }

    #[test]
    fn test_pre_post_transaction_balances() {
        let (mut genesis_config, _mint_keypair) = create_genesis_config(500);
        let fee_rate_governor = FeeRateGovernor::new(1, 0);
        genesis_config.fee_rate_governor = fee_rate_governor;
        let parent = Arc::new(Bank::new(&genesis_config));
        let bank0 = Arc::new(new_from_parent(&parent));

        let keypair0 = Keypair::new();
        let keypair1 = Keypair::new();
        let pubkey0 = Pubkey::new_rand();
        let pubkey1 = Pubkey::new_rand();
        let pubkey2 = Pubkey::new_rand();
        let keypair0_account = Account::new(8, 0, &Pubkey::default());
        let keypair1_account = Account::new(9, 0, &Pubkey::default());
        let account0 = Account::new(11, 0, &&Pubkey::default());
        bank0.store_account(&keypair0.pubkey(), &keypair0_account);
        bank0.store_account(&keypair1.pubkey(), &keypair1_account);
        bank0.store_account(&pubkey0, &account0);

        let blockhash = bank0.last_blockhash();

        let tx0 = system_transaction::transfer(&keypair0, &pubkey0, 2, blockhash);
        let tx1 = system_transaction::transfer(&Keypair::new(), &pubkey1, 2, blockhash);
        let tx2 = system_transaction::transfer(&keypair1, &pubkey2, 12, blockhash);
        let txs = vec![tx0, tx1, tx2];

        let lock_result = bank0.prepare_batch(&txs, None);
        let (transaction_results, transaction_balances_set) =
            bank0.load_execute_and_commit_transactions(&lock_result, MAX_PROCESSING_AGE, true);

        assert_eq!(transaction_balances_set.pre_balances.len(), 3);
        assert_eq!(transaction_balances_set.post_balances.len(), 3);

        assert!(transaction_results.processing_results[0].0.is_ok());
        assert_eq!(transaction_balances_set.pre_balances[0], vec![8, 11, 1]);
        assert_eq!(transaction_balances_set.post_balances[0], vec![5, 13, 1]);

        // Failed transactions still produce balance sets
        // This is a TransactionError - not possible to charge fees
        assert!(transaction_results.processing_results[1].0.is_err());
        assert_eq!(transaction_balances_set.pre_balances[1], vec![0, 0, 1]);
        assert_eq!(transaction_balances_set.post_balances[1], vec![0, 0, 1]);

        // Failed transactions still produce balance sets
        // This is an InstructionError - fees charged
        assert!(transaction_results.processing_results[2].0.is_err());
        assert_eq!(transaction_balances_set.pre_balances[2], vec![9, 0, 1]);
        assert_eq!(transaction_balances_set.post_balances[2], vec![8, 0, 1]);
    }

    #[test]
    fn test_transaction_with_duplicate_accounts_in_instruction() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let mut bank = Bank::new(&genesis_config);

        fn mock_process_instruction(
            _program_id: &Pubkey,
            keyed_accounts: &[KeyedAccount],
            data: &[u8],
        ) -> result::Result<(), InstructionError> {
            let lamports = data[0] as u64;
            {
                let mut to_account = keyed_accounts[1].try_account_ref_mut()?;
                let mut dup_account = keyed_accounts[2].try_account_ref_mut()?;
                dup_account.lamports -= lamports;
                to_account.lamports += lamports;
            }
            keyed_accounts[0].try_account_ref_mut()?.lamports -= lamports;
            keyed_accounts[1].try_account_ref_mut()?.lamports += lamports;
            Ok(())
        }

        let mock_program_id = Pubkey::new(&[2u8; 32]);
        bank.add_builtin_program("mock_program", mock_program_id, mock_process_instruction);

        let from_pubkey = Pubkey::new_rand();
        let to_pubkey = Pubkey::new_rand();
        let dup_pubkey = from_pubkey;
        let from_account = Account::new(100, 1, &mock_program_id);
        let to_account = Account::new(0, 1, &mock_program_id);
        bank.store_account(&from_pubkey, &from_account);
        bank.store_account(&to_pubkey, &to_account);

        let account_metas = vec![
            AccountMeta::new(from_pubkey, false),
            AccountMeta::new(to_pubkey, false),
            AccountMeta::new(dup_pubkey, false),
        ];
        let instruction = Instruction::new(mock_program_id, &10, account_metas);
        let tx = Transaction::new_signed_with_payer(
            &[instruction],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair],
            bank.last_blockhash(),
        );

        let result = bank.process_transaction(&tx);
        assert_eq!(result, Ok(()));
        assert_eq!(bank.get_balance(&from_pubkey), 80);
        assert_eq!(bank.get_balance(&to_pubkey), 20);
    }

    #[test]
    fn test_transaction_with_program_ids_passed_to_programs() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let mut bank = Bank::new(&genesis_config);

        fn mock_process_instruction(
            _program_id: &Pubkey,
            _keyed_accounts: &[KeyedAccount],
            _data: &[u8],
        ) -> result::Result<(), InstructionError> {
            Ok(())
        }

        let mock_program_id = Pubkey::new(&[2u8; 32]);
        bank.add_builtin_program("mock_program", mock_program_id, mock_process_instruction);

        let from_pubkey = Pubkey::new_rand();
        let to_pubkey = Pubkey::new_rand();
        let dup_pubkey = from_pubkey;
        let from_account = Account::new(100, 1, &mock_program_id);
        let to_account = Account::new(0, 1, &mock_program_id);
        bank.store_account(&from_pubkey, &from_account);
        bank.store_account(&to_pubkey, &to_account);

        let account_metas = vec![
            AccountMeta::new(from_pubkey, false),
            AccountMeta::new(to_pubkey, false),
            AccountMeta::new(dup_pubkey, false),
            AccountMeta::new(mock_program_id, false),
        ];
        let instruction = Instruction::new(mock_program_id, &10, account_metas);
        let tx = Transaction::new_signed_with_payer(
            &[instruction],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair],
            bank.last_blockhash(),
        );

        let result = bank.process_transaction(&tx);
        assert_eq!(result, Ok(()));
    }

    #[test]
    fn test_account_ids_after_program_ids() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let mut bank = Bank::new(&genesis_config);

        let from_pubkey = Pubkey::new_rand();
        let to_pubkey = Pubkey::new_rand();

        let account_metas = vec![
            AccountMeta::new(from_pubkey, false),
            AccountMeta::new(to_pubkey, false),
        ];

        let instruction = Instruction::new(solana_vote_program::id(), &10, account_metas);
        let mut tx = Transaction::new_signed_with_payer(
            &[instruction],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair],
            bank.last_blockhash(),
        );

        tx.message.account_keys.push(Pubkey::new_rand());

        bank.add_builtin_program(
            "mock_vote",
            solana_vote_program::id(),
            mock_ok_vote_processor,
        );
        let result = bank.process_transaction(&tx);
        assert_eq!(result, Ok(()));
        let account = bank.get_account(&solana_vote_program::id()).unwrap();
        info!("account: {:?}", account);
        assert!(account.executable);
    }

    #[test]
    fn test_incinerator() {
        let (genesis_config, mint_keypair) = create_genesis_config(1_000_000_000_000);
        let bank0 = Arc::new(Bank::new(&genesis_config));

        // Move to the first normal slot so normal rent behaviour applies
        let bank = Bank::new_from_parent(
            &bank0,
            &Pubkey::default(),
            genesis_config.epoch_schedule.first_normal_slot,
        );
        let pre_capitalization = bank.capitalization();

        // Burn a non-rent exempt amount
        let burn_amount = bank.get_minimum_balance_for_rent_exemption(0) - 1;

        assert_eq!(bank.get_balance(&incinerator::id()), 0);
        bank.transfer(burn_amount, &mint_keypair, &incinerator::id())
            .unwrap();
        assert_eq!(bank.get_balance(&incinerator::id()), burn_amount);
        bank.freeze();
        assert_eq!(bank.get_balance(&incinerator::id()), 0);

        // Ensure that no rent was collected, and the entire burn amount was removed from bank
        // capitalization
        assert_eq!(bank.capitalization(), pre_capitalization - burn_amount);
    }

    #[test]
    fn test_duplicate_account_key() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let mut bank = Bank::new(&genesis_config);

        let from_pubkey = Pubkey::new_rand();
        let to_pubkey = Pubkey::new_rand();

        let account_metas = vec![
            AccountMeta::new(from_pubkey, false),
            AccountMeta::new(to_pubkey, false),
        ];

        bank.add_builtin_program(
            "mock_vote",
            solana_vote_program::id(),
            mock_ok_vote_processor,
        );

        let instruction = Instruction::new(solana_vote_program::id(), &10, account_metas);
        let mut tx = Transaction::new_signed_with_payer(
            &[instruction],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair],
            bank.last_blockhash(),
        );
        tx.message.account_keys.push(from_pubkey);

        let result = bank.process_transaction(&tx);
        assert_eq!(result, Err(TransactionError::AccountLoadedTwice));
    }

    #[test]
    fn test_program_id_as_payer() {
        solana_logger::setup();
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let mut bank = Bank::new(&genesis_config);

        let from_pubkey = Pubkey::new_rand();
        let to_pubkey = Pubkey::new_rand();

        let account_metas = vec![
            AccountMeta::new(from_pubkey, false),
            AccountMeta::new(to_pubkey, false),
        ];

        bank.add_builtin_program(
            "mock_vote",
            solana_vote_program::id(),
            mock_ok_vote_processor,
        );

        let instruction = Instruction::new(solana_vote_program::id(), &10, account_metas);
        let mut tx = Transaction::new_signed_with_payer(
            &[instruction],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair],
            bank.last_blockhash(),
        );

        info!(
            "mint: {} account keys: {:?}",
            mint_keypair.pubkey(),
            tx.message.account_keys
        );
        assert_eq!(tx.message.account_keys.len(), 4);
        tx.message.account_keys.clear();
        tx.message.account_keys.push(solana_vote_program::id());
        tx.message.account_keys.push(mint_keypair.pubkey());
        tx.message.account_keys.push(from_pubkey);
        tx.message.account_keys.push(to_pubkey);
        tx.message.instructions[0].program_id_index = 0;
        tx.message.instructions[0].accounts.clear();
        tx.message.instructions[0].accounts.push(2);
        tx.message.instructions[0].accounts.push(3);

        let result = bank.process_transaction(&tx);
        assert_eq!(result, Err(TransactionError::SanitizeFailure));
    }

    fn mock_ok_vote_processor(
        _pubkey: &Pubkey,
        _ka: &[KeyedAccount],
        _data: &[u8],
    ) -> std::result::Result<(), InstructionError> {
        Ok(())
    }

    #[test]
    fn test_ref_account_key_after_program_id() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let mut bank = Bank::new(&genesis_config);

        let from_pubkey = Pubkey::new_rand();
        let to_pubkey = Pubkey::new_rand();

        let account_metas = vec![
            AccountMeta::new(from_pubkey, false),
            AccountMeta::new(to_pubkey, false),
        ];

        bank.add_builtin_program(
            "mock_vote",
            solana_vote_program::id(),
            mock_ok_vote_processor,
        );

        let instruction = Instruction::new(solana_vote_program::id(), &10, account_metas);
        let mut tx = Transaction::new_signed_with_payer(
            &[instruction],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair],
            bank.last_blockhash(),
        );

        tx.message.account_keys.push(Pubkey::new_rand());
        assert_eq!(tx.message.account_keys.len(), 5);
        tx.message.instructions[0].accounts.remove(0);
        tx.message.instructions[0].accounts.push(4);

        let result = bank.process_transaction(&tx);
        assert_eq!(result, Ok(()));
    }

    #[test]
    fn test_fuzz_instructions() {
        solana_logger::setup();
        use rand::{thread_rng, Rng};
        let (genesis_config, _mint_keypair) = create_genesis_config(1_000_000_000);
        let mut bank = Bank::new(&genesis_config);

        let max_programs = 5;
        let program_keys: Vec<_> = (0..max_programs)
            .enumerate()
            .map(|i| {
                let key = Pubkey::new_rand();
                let name = format!("program{:?}", i);
                bank.add_builtin_program(&name, key, mock_ok_vote_processor);
                (key, name.as_bytes().to_vec())
            })
            .collect();
        let max_keys = 100;
        let keys: Vec<_> = (0..max_keys)
            .enumerate()
            .map(|_| {
                let key = Pubkey::new_rand();
                let balance = if thread_rng().gen_ratio(9, 10) {
                    let lamports = if thread_rng().gen_ratio(1, 5) {
                        thread_rng().gen_range(0, 10)
                    } else {
                        thread_rng().gen_range(20, 100)
                    };
                    let space = thread_rng().gen_range(0, 10);
                    let owner = Pubkey::default();
                    let account = Account::new(lamports, space, &owner);
                    bank.store_account(&key, &account);
                    lamports
                } else {
                    0
                };
                (key, balance)
            })
            .collect();
        let mut results = HashMap::new();
        for _ in 0..2_000 {
            let num_keys = if thread_rng().gen_ratio(1, 5) {
                thread_rng().gen_range(0, max_keys)
            } else {
                thread_rng().gen_range(1, 4)
            };
            let num_instructions = thread_rng().gen_range(0, max_keys - num_keys);

            let mut account_keys: Vec<_> = if thread_rng().gen_ratio(1, 5) {
                (0..num_keys)
                    .map(|_| {
                        let idx = thread_rng().gen_range(0, keys.len());
                        keys[idx].0
                    })
                    .collect()
            } else {
                use std::collections::HashSet;
                let mut inserted = HashSet::new();
                (0..num_keys)
                    .map(|_| {
                        let mut idx;
                        loop {
                            idx = thread_rng().gen_range(0, keys.len());
                            if !inserted.contains(&idx) {
                                break;
                            }
                        }
                        inserted.insert(idx);
                        keys[idx].0
                    })
                    .collect()
            };

            let instructions: Vec<_> = if num_keys > 0 {
                (0..num_instructions)
                    .map(|_| {
                        let num_accounts_to_pass = thread_rng().gen_range(0, num_keys);
                        let account_indexes = (0..num_accounts_to_pass)
                            .map(|_| thread_rng().gen_range(0, num_keys))
                            .collect();
                        let program_index: u8 = thread_rng().gen_range(0, num_keys) as u8;
                        if thread_rng().gen_ratio(4, 5) {
                            let programs_index = thread_rng().gen_range(0, program_keys.len());
                            account_keys[program_index as usize] = program_keys[programs_index].0;
                        }
                        CompiledInstruction::new(program_index, &10, account_indexes)
                    })
                    .collect()
            } else {
                vec![]
            };

            let account_keys_len = std::cmp::max(account_keys.len(), 2);
            let num_signatures = if thread_rng().gen_ratio(1, 5) {
                thread_rng().gen_range(0, account_keys_len + 10)
            } else {
                thread_rng().gen_range(1, account_keys_len)
            };

            let num_required_signatures = if thread_rng().gen_ratio(1, 5) {
                thread_rng().gen_range(0, account_keys_len + 10) as u8
            } else {
                thread_rng().gen_range(1, std::cmp::max(2, num_signatures)) as u8
            };
            let num_readonly_signed_accounts = if thread_rng().gen_ratio(1, 5) {
                thread_rng().gen_range(0, account_keys_len) as u8
            } else {
                let max = if num_required_signatures > 1 {
                    num_required_signatures - 1
                } else {
                    1
                };
                thread_rng().gen_range(0, max) as u8
            };

            let num_readonly_unsigned_accounts = if thread_rng().gen_ratio(1, 5)
                || (num_required_signatures as usize) >= account_keys_len
            {
                thread_rng().gen_range(0, account_keys_len) as u8
            } else {
                thread_rng().gen_range(0, account_keys_len - num_required_signatures as usize) as u8
            };

            let header = MessageHeader {
                num_required_signatures,
                num_readonly_signed_accounts,
                num_readonly_unsigned_accounts,
            };
            let message = Message {
                header,
                account_keys,
                recent_blockhash: bank.last_blockhash(),
                instructions,
            };

            let tx = Transaction {
                signatures: vec![Signature::default(); num_signatures],
                message,
            };

            let result = bank.process_transaction(&tx);
            for (key, balance) in &keys {
                assert_eq!(bank.get_balance(key), *balance);
            }
            for (key, name) in &program_keys {
                let account = bank.get_account(key).unwrap();
                assert!(account.executable);
                assert_eq!(account.data, *name);
            }
            info!("result: {:?}", result);
            let result_key = format!("{:?}", result);
            *results.entry(result_key).or_insert(0) += 1;
        }
        info!("results: {:?}", results);
    }

    #[test]
    fn test_bank_hash_consistency() {
        let mut genesis_config = GenesisConfig::new(
            &[(
                Pubkey::new(&[42; 32]),
                Account::new(1_000_000_000_000, 0, &system_program::id()),
            )],
            &[],
        );
        genesis_config.creation_time = 0;
        let mut bank = Arc::new(Bank::new(&genesis_config));
        // Check a few slots, cross an epoch boundary
        assert_eq!(bank.get_slots_in_epoch(0), 32);
        loop {
            goto_end_of_slot(Arc::get_mut(&mut bank).unwrap());
            if bank.slot == 0 {
                assert_eq!(
                    bank.hash().to_string(),
                    "DJ5664svVgjZ8sRLZSrdYAjaAzJe3aEGVBDpZEeoZJ5u"
                );
            }
            if bank.slot == 32 {
                assert_eq!(
                    bank.hash().to_string(),
                    "5yZDar5HaXypoeNnE9mEfVwJEEyDCP5W1pLwhuouPjqN"
                );
            }
            if bank.slot == 64 {
                assert_eq!(
                    bank.hash().to_string(),
                    "FmPBRC6AAZgXu1QiqZ445FhLYZXun9KTtjMMKqCim9Hd"
                );
            }
            if bank.slot == 128 {
                assert_eq!(
                    bank.hash().to_string(),
                    "Aqi2QcSoxaYu2QJHKaMHi9G8J2vNEtjpuKzjj5rHP9wr"
                );
                break;
            }
            bank = Arc::new(new_from_parent(&bank));
        }
    }

    #[test]
    fn test_same_program_id_uses_unqiue_executable_accounts() {
        fn nested_processor(
            _program_id: &Pubkey,
            keyed_accounts: &[KeyedAccount],
            _data: &[u8],
        ) -> result::Result<(), InstructionError> {
            assert_eq!(42, keyed_accounts[0].lamports().unwrap());
            let mut account = keyed_accounts[0].try_account_ref_mut()?;
            account.lamports += 1;
            Ok(())
        }

        let (genesis_config, mint_keypair) = create_genesis_config(50000);
        let mut bank = Bank::new(&genesis_config);

        // Add a new program
        let program1_pubkey = Pubkey::new_rand();
        bank.add_builtin_program("program", program1_pubkey, nested_processor);

        // Add a new program owned by the first
        let program2_pubkey = Pubkey::new_rand();
        let mut program2_account = Account::new(42, 1, &program1_pubkey);
        program2_account.executable = true;
        bank.store_account(&program2_pubkey, &program2_account);

        let instruction = Instruction::new(program2_pubkey, &10, vec![]);
        let tx = Transaction::new_signed_with_payer(
            &[instruction.clone(), instruction],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair],
            bank.last_blockhash(),
        );
        assert!(bank.process_transaction(&tx).is_ok());
        assert_eq!(1, bank.get_balance(&program1_pubkey));
        assert_eq!(42, bank.get_balance(&program2_pubkey));
    }

    #[test]
    fn test_process_stale_slot_with_budget() {
        solana_logger::setup();

        let (genesis_config, _mint_keypair) = create_genesis_config(1_000_000_000);
        let pubkey1 = Pubkey::new_rand();
        let pubkey2 = Pubkey::new_rand();

        let mut bank = Arc::new(Bank::new(&genesis_config));
        bank.lazy_rent_collection.store(true, Ordering::Relaxed);
        assert_eq!(bank.process_stale_slot_with_budget(0, 0), 0);
        assert_eq!(bank.process_stale_slot_with_budget(133, 0), 133);

        assert_eq!(bank.process_stale_slot_with_budget(0, 100), 0);
        assert_eq!(bank.process_stale_slot_with_budget(33, 100), 0);
        assert_eq!(bank.process_stale_slot_with_budget(133, 100), 33);

        goto_end_of_slot(Arc::<Bank>::get_mut(&mut bank).unwrap());

        bank.squash();

        let some_lamports = 123;
        let mut bank = Arc::new(new_from_parent(&bank));
        bank.deposit(&pubkey1, some_lamports);
        bank.deposit(&pubkey2, some_lamports);

        goto_end_of_slot(Arc::<Bank>::get_mut(&mut bank).unwrap());

        let mut bank = Arc::new(new_from_parent(&bank));
        bank.deposit(&pubkey1, some_lamports);

        goto_end_of_slot(Arc::<Bank>::get_mut(&mut bank).unwrap());

        bank.squash();
        bank.clean_accounts();
        let force_to_return_alive_account = 0;
        assert_eq!(
            bank.process_stale_slot_with_budget(22, force_to_return_alive_account),
            22
        );

        let mut consumed_budgets = (0..3)
            .map(|_| bank.process_stale_slot_with_budget(0, force_to_return_alive_account))
            .collect::<Vec<_>>();
        consumed_budgets.sort();
        assert_eq!(consumed_budgets, vec![0, 1, 8]);
    }

    #[test]
    fn test_upgrade_epoch() {
        let GenesisConfigInfo {
            mut genesis_config,
            mint_keypair,
            ..
        } = create_genesis_config_with_leader(500, &Pubkey::new_rand(), 0);
        genesis_config.fee_rate_governor = FeeRateGovernor::new(1, 0);
        let bank = Arc::new(Bank::new(&genesis_config));

        // Jump to the test-only upgrade epoch -- see `Bank::upgrade_epoch()`
        let bank = Bank::new_from_parent(
            &bank,
            &Pubkey::default(),
            genesis_config
                .epoch_schedule
                .get_first_slot_in_epoch(0xdead),
        );

        assert_eq!(bank.get_balance(&mint_keypair.pubkey()), 500);

        // Normal transfers are not allowed
        assert_eq!(
            bank.transfer(2, &mint_keypair, &mint_keypair.pubkey()),
            Err(TransactionError::ClusterMaintenance)
        );
        assert_eq!(bank.get_balance(&mint_keypair.pubkey()), 500); // no transaction fee charged

        let vote_pubkey = Pubkey::new_rand();
        let authorized_voter = Keypair::new();

        // VoteInstruction::Vote is allowed.  The transaction fails with a vote program instruction
        // error because the vote account is not actually setup
        let tx = Transaction::new_signed_with_payer(
            &[vote_instruction::vote(
                &vote_pubkey,
                &authorized_voter.pubkey(),
                Vote::new(vec![1], Hash::default()),
            )],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair, &authorized_voter],
            bank.last_blockhash(),
        );
        assert_eq!(
            bank.process_transaction(&tx),
            Err(TransactionError::InstructionError(
                0,
                InstructionError::InvalidAccountData
            ))
        );
        assert_eq!(bank.get_balance(&mint_keypair.pubkey()), 498); // transaction fee charged

        // VoteInstruction::VoteSwitch is allowed.  The transaction fails with a vote program
        // instruction error because the vote account is not actually setup
        let tx = Transaction::new_signed_with_payer(
            &[vote_instruction::vote_switch(
                &vote_pubkey,
                &authorized_voter.pubkey(),
                Vote::new(vec![1], Hash::default()),
                Hash::default(),
            )],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair, &authorized_voter],
            bank.last_blockhash(),
        );
        assert_eq!(
            bank.process_transaction(&tx),
            Err(TransactionError::InstructionError(
                0,
                InstructionError::InvalidAccountData
            ))
        );
        assert_eq!(bank.get_balance(&mint_keypair.pubkey()), 496); // transaction fee charged

        // Other vote program instructions, like VoteInstruction::UpdateCommission are not allowed
        let tx = Transaction::new_signed_with_payer(
            &[vote_instruction::update_commission(
                &vote_pubkey,
                &authorized_voter.pubkey(),
                123,
            )],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair, &authorized_voter],
            bank.last_blockhash(),
        );
        assert_eq!(
            bank.process_transaction(&tx),
            Err(TransactionError::ClusterMaintenance)
        );
        assert_eq!(bank.get_balance(&mint_keypair.pubkey()), 496); // no transaction fee charged
    }
}