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::{Accounts, TransactionAccounts, TransactionLoadResult, TransactionLoaders},
    accounts_db::{
        AccountsDBSerialize, AppendVecId, ErrorCounters, SnapshotStorage, SnapshotStorages,
    },
    blockhash_queue::BlockhashQueue,
    message_processor::{MessageProcessor, ProcessInstruction},
    nonce_utils,
    rent_collector::RentCollector,
    serde_utils::{
        deserialize_atomicbool, deserialize_atomicu64, serialize_atomicbool, serialize_atomicu64,
    },
    stakes::Stakes,
    status_cache::{SlotDelta, StatusCache},
    storage_utils,
    storage_utils::StorageAccounts,
    system_instruction_processor::{get_system_account_kind, SystemAccountKind},
    transaction_batch::TransactionBatch,
    transaction_utils::OrderedIterator,
};
use bincode::{deserialize_from, serialize_into};
use byteorder::{ByteOrder, LittleEndian};
use itertools::Itertools;
use log::*;
use serde::{Deserialize, Serialize};
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::{get_segment_from_slot, Epoch, Slot, UnixTimestamp, MAX_RECENT_BLOCKHASHES},
    epoch_schedule::EpochSchedule,
    fee_calculator::{FeeCalculator, FeeRateGovernor},
    genesis_config::GenesisConfig,
    hard_forks::HardForks,
    hash::{extend_and_hash, hashv, Hash},
    inflation::Inflation,
    native_loader, nonce,
    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};
use solana_vote_program::vote_state::VoteState;
use std::{
    cell::RefCell,
    collections::HashMap,
    io::{BufReader, Cursor, Error as IOError, Read},
    path::{Path, PathBuf},
    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_SNAPSHOT_DATA_FILE_SIZE: u64 = 32 * 1024 * 1024 * 1024; // 32 GiB

pub const MAX_LEADER_SCHEDULE_STAKES: Epoch = 5;

type BankStatusCache = StatusCache<Result<()>>;
pub type BankSlotDelta = SlotDelta<Result<()>>;
type TransactionAccountRefCells = Vec<Rc<RefCell<Account>>>;
type TransactionLoaderRefCells = Vec<Vec<(Pubkey, RefCell<Account>)>>;

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

    /// Previous checkpoint of this bank
    parent: RwLock<Option<Arc<Bank>>>,

    /// Current slot
    slot: Slot,
}

impl BankRc {
    pub fn new(account_paths: Vec<PathBuf>, id: AppendVecId, slot: Slot) -> Self {
        let accounts = Accounts::new(account_paths);
        accounts
            .accounts_db
            .next_id
            .store(id as usize, Ordering::Relaxed);
        BankRc {
            accounts: Arc::new(accounts),
            parent: RwLock::new(None),
            slot,
        }
    }

    pub fn accounts_from_stream<R: Read, P: AsRef<Path>>(
        &self,
        mut stream: &mut BufReader<R>,
        local_paths: &[PathBuf],
        append_vecs_path: P,
    ) -> std::result::Result<(), IOError> {
        let _len: usize =
            deserialize_from(&mut stream).map_err(|e| BankRc::get_io_error(&e.to_string()))?;
        self.accounts
            .accounts_from_stream(stream, local_paths, append_vecs_path)?;

        Ok(())
    }

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

    fn get_io_error(error: &str) -> IOError {
        warn!("BankRc error: {:?}", error);
        std::io::Error::new(std::io::ErrorKind::Other, error)
    }
}

pub struct BankRcSerialize<'a, 'b> {
    pub bank_rc: &'a BankRc,
    pub snapshot_storages: &'b [SnapshotStorage],
}

impl<'a, 'b> Serialize for BankRcSerialize<'a, 'b> {
    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
    where
        S: serde::ser::Serializer,
    {
        use serde::ser::Error;
        let mut wr = Cursor::new(Vec::new());
        let accounts_db_serialize = AccountsDBSerialize::new(
            &*self.bank_rc.accounts.accounts_db,
            self.bank_rc.slot,
            self.snapshot_storages,
        );
        serialize_into(&mut wr, &accounts_db_serialize).map_err(Error::custom)?;
        let len = wr.position() as usize;
        serializer.serialize_bytes(&wr.into_inner()[..len])
    }
}

#[derive(Default)]
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 {
        match self {
            HashAgeKind::DurableNonce(_, _) => true,
            _ => false,
        }
    }
}

/// Manager for the state of all accounts and programs after processing its entries.
#[derive(Default, Deserialize, Serialize)]
pub struct Bank {
    /// References to accounts, parent and signature status
    #[serde(skip)]
    pub rc: BankRc,

    #[serde(skip)]
    pub src: StatusCacheRc,

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

    /// The set of parents including this bank
    pub ancestors: HashMap<Slot, usize>,

    /// 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
    #[serde(serialize_with = "serialize_atomicu64")]
    #[serde(deserialize_with = "deserialize_atomicu64")]
    transaction_count: AtomicU64,

    /// Bank tick height
    #[serde(serialize_with = "serialize_atomicu64")]
    #[serde(deserialize_with = "deserialize_atomicu64")]
    tick_height: AtomicU64,

    /// The number of signatures from valid transactions in this slot
    #[serde(serialize_with = "serialize_atomicu64")]
    #[serde(deserialize_with = "deserialize_atomicu64")]
    signature_count: AtomicU64,

    /// Total capitalization, used to calculate inflation
    #[serde(serialize_with = "serialize_atomicu64")]
    #[serde(deserialize_with = "deserialize_atomicu64")]
    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,

    /// The number of slots per Storage segment
    slots_per_segment: 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
    #[serde(serialize_with = "serialize_atomicu64")]
    #[serde(deserialize_with = "deserialize_atomicu64")]
    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
    #[serde(serialize_with = "serialize_atomicu64")]
    #[serde(deserialize_with = "deserialize_atomicu64")]
    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>,

    /// cache of validator and archiver storage accounts for this fork
    storage_accounts: RwLock<StorageAccounts>,

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

    /// A boolean reflecting whether any entries were recorded into the PoH
    /// stream for the slot == self.slot
    #[serde(serialize_with = "serialize_atomicbool")]
    #[serde(deserialize_with = "deserialize_atomicbool")]
    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)
    #[serde(skip)]
    entered_epoch_callback: Arc<RwLock<Option<EnteredEpochCallback>>>,

    /// Last time when the cluster info vote listener has synced with this bank
    #[serde(skip)]
    pub last_vote_sync: AtomicU64,

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

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>) -> Self {
        let mut bank = Self::default();
        bank.ancestors.insert(bank.slot(), 0);
        bank.rc.accounts = Arc::new(Accounts::new(paths));
        bank.process_genesis_config(genesis_config);
        // 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, stakes.clone());
            }
            bank.update_stake_history(None);
        }
        bank.update_clock();
        bank.update_rent();
        bank.update_epoch_schedule();
        bank.update_recent_blockhashes();
        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,
            slots_per_segment: parent.slots_per_segment,
            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(),
            storage_accounts: RwLock::new(parent.storage_accounts.read().unwrap().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: MessageProcessor::default(),
            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,
        };

        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)
            }
        }

        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();
        new.update_recent_blockhashes();
        new
    }

    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 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 mut new_account = updater(&old_account);

        // Normally, just use the hash from parent slot. However, use the
        // existing stored hash if any for the sake of bank hash's idempotent.
        if let Some((modified_account, _)) = self.get_account_modified_since_parent(pubkey) {
            new_account.hash = modified_account.hash;
        } else if let Some(old_account) = old_account {
            new_account.hash = old_account.hash;
        }

        self.store_account(pubkey, &new_account);
    }

    fn update_clock(&self) {
        self.update_sysvar_account(&sysvar::clock::id(), |_| {
            sysvar::clock::Clock {
                slot: self.slot,
                segment: get_segment_from_slot(self.slot, self.slots_per_segment),
                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(),
            }
            .create_account(1)
        });
    }

    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(1)
        });
    }

    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(1)
        });
    }

    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)
            });

            self.epoch_stakes
                .insert(leader_schedule_epoch, self.stakes.read().unwrap().clone());
        }
    }

    fn update_fees(&self) {
        self.update_sysvar_account(&sysvar::fees::id(), |_| {
            sysvar::fees::create_account(1, &self.fee_calculator)
        });
    }

    fn update_rent(&self) {
        self.update_sysvar_account(&sysvar::rent::id(), |_| {
            sysvar::rent::create_account(1, &self.rent_collector.rent)
        });
    }

    fn update_epoch_schedule(&self) {
        self.update_sysvar_account(&sysvar::epoch_schedule::id(), |_| {
            sysvar::epoch_schedule::create_account(1, &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(), |_| {
            sysvar::stake_history::create_account(1, 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, storage_rewards) = {
            let inflation = self.inflation.read().unwrap();

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

        let validator_points = self.stakes.write().unwrap().claim_points();
        let storage_points = self.storage_accounts.write().unwrap().claim_points();

        let (validator_point_value, storage_point_value) = self.check_point_values(
            validator_rewards / validator_points as f64,
            storage_rewards / storage_points as f64,
        );
        self.update_sysvar_account(&sysvar::rewards::id(), |_| {
            sysvar::rewards::create_account(1, validator_point_value, storage_point_value)
        });

        let validator_rewards = self.pay_validator_rewards(validator_point_value);
        self.capitalization.fetch_add(
            validator_rewards + storage_rewards as u64,
            Ordering::Relaxed,
        );
    }

    /// 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, point_value: f64) -> u64 {
        let stake_history = self.stakes.read().unwrap().history().clone();
        let mut validator_rewards = HashMap::new();

        let total_validator_rewards = self
            .stake_delegations()
            .iter()
            .map(|(stake_pubkey, delegation)| {
                match (
                    self.get_account(&stake_pubkey),
                    self.get_account(&delegation.voter_pubkey),
                ) {
                    (Some(mut stake_account), Some(mut vote_account)) => {
                        let rewards = stake_state::redeem_rewards(
                            &mut stake_account,
                            &mut vote_account,
                            point_value,
                            Some(&stake_history),
                        );
                        if let Ok((stakers_reward, voters_reward)) = rewards {
                            self.store_account(&stake_pubkey, &stake_account);
                            self.store_account(&delegation.voter_pubkey, &vote_account);

                            if voters_reward > 0 {
                                *validator_rewards
                                    .entry(delegation.voter_pubkey)
                                    .or_insert(0i64) += voters_reward as i64;
                            }

                            if stakers_reward > 0 {
                                *validator_rewards.entry(*stake_pubkey).or_insert(0i64) +=
                                    stakers_reward as i64;
                            }

                            stakers_reward + voters_reward
                        } else {
                            debug!(
                                "stake_state::redeem_rewards() failed for {}: {:?}",
                                stake_pubkey, rewards
                            );
                            0
                        }
                    }
                    (_, _) => 0,
                }
            })
            .sum();

        assert_eq!(self.rewards, None);
        self.rewards = Some(validator_rewards.drain().collect());
        total_validator_rewards
    }

    pub fn update_recent_blockhashes(&self) {
        self.update_sysvar_account(&sysvar::recent_blockhashes::id(), |_| {
            let blockhash_queue = self.blockhash_queue.read().unwrap();
            let recent_blockhash_iter = blockhash_queue.get_recent_blockhashes();
            sysvar::recent_blockhashes::create_account_with_data(1, recent_blockhash_iter)
        });
    }

    // If the point values are not `normal`, bring them back into range and
    // set them to the last value or 0.
    fn check_point_values(
        &self,
        mut validator_point_value: f64,
        mut storage_point_value: f64,
    ) -> (f64, f64) {
        let rewards = sysvar::rewards::Rewards::from_account(
            &self
                .get_account(&sysvar::rewards::id())
                .unwrap_or_else(|| sysvar::rewards::create_account(1, 0.0, 0.0)),
        )
        .unwrap_or_else(Default::default);
        if !validator_point_value.is_normal() {
            validator_point_value = rewards.validator_point_value;
        }
        if !storage_point_value.is_normal() {
            storage_point_value = rewards.storage_point_value
        }
        (validator_point_value, storage_point_value)
    }

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

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

            // 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.slots_per_segment = genesis_config.slots_per_segment;
        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.register_native_instruction_processor(name, program_id);
        }
    }

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

    /// 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 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 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);
        }
    }

    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 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(),
            )
        }
    }

    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_refs(
        &self,
        txs: &[Transaction],
        iteration_order: Option<&[usize]>,
        lock_results: &[Result<()>],
        error_counters: &mut ErrorCounters,
    ) -> Vec<Result<()>> {
        OrderedIterator::new(txs, iteration_order)
            .zip(lock_results)
            .map(|(tx, lock_res)| {
                if lock_res.is_ok() && !tx.verify_refs() {
                    error_counters.invalid_account_index += 1;
                    Err(TransactionError::InvalidAccountIndex)
                } else {
                    lock_res.clone()
                }
            })
            .collect()
    }
    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()
    }

    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)
            })
    }

    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 refs_results = self.check_refs(txs, iteration_order, lock_results, &mut error_counters);
        let age_results = self.check_age(
            txs,
            iteration_order,
            refs_results,
            max_age,
            &mut error_counters,
        );
        self.check_signatures(txs, iteration_order, age_results, &mut error_counters)
    }

    pub fn collect_balances(&self, batch: &[Transaction]) -> TransactionBalances {
        let mut balances: TransactionBalances = vec![];
        for transaction in batch.iter() {
            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
            );
        }
    }

    /// Converts Accounts into RefCell<Account>, this involves moving
    /// ownership by draining the source
    #[allow(clippy::wrong_self_convention)]
    fn into_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 from_refcells(
        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,
    ) -> (
        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::into_refcells(accounts, loaders);

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

                    Self::from_refcells(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(),
        );
        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);
    }

    /// 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.transactions())
        } else {
            vec![]
        };
        let (mut loaded_accounts, executed, _, tx_count, signature_count) =
            self.load_and_execute_transactions(batch, max_age);

        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.transactions())
        } 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_RECENT_BLOCKHASHES, 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);
        } else if storage_utils::is_storage(account) {
            self.storage_accounts
                .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(&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 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.rc
            .accounts
            .load_slow(&self.ancestors, pubkey)
            .map(|(acc, _slot)| acc)
    }

    // 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(), program_id)
    }

    pub fn get_account_modified_since_parent(&self, pubkey: &Pubkey) -> Option<(Account, Slot)> {
        let just_self: HashMap<u64, usize> = 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 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_confirmation_status(
        &self,
        signature: &Signature,
    ) -> Option<(usize, Result<()>)> {
        let rcache = self.src.status_cache.read().unwrap();
        rcache.get_signature_status_slow(signature, &self.ancestors)
    }

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

    pub fn has_signature(&self, signature: &Signature) -> bool {
        self.get_signature_confirmation_status(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: {}",
            self.slot(),
            hash,
            accounts_delta_hash.hash,
            self.signature_count(),
            self.last_blockhash(),
        );

        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 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();
        // 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 slots per segment
    pub fn slots_per_segment(&self) -> u64 {
        self.slots_per_segment
    }

    /// 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 capititalization 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)) || storage_utils::is_storage(account)
                    })
            {
                if Stakes::is_stake(account) {
                    self.stakes.write().unwrap().store(pubkey, account);
                } else if storage_utils::is_storage(account) {
                    self.storage_accounts
                        .write()
                        .unwrap()
                        .store(pubkey, account);
                }
            }
        }
    }

    pub fn storage_accounts(&self) -> StorageAccounts {
        self.storage_accounts.read().unwrap().clone()
    }

    /// 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()
    }

    /// 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(Stakes::vote_accounts)
    }

    /// 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) -> (u64, u64) {
        self.epoch_schedule.get_epoch_and_slot_index(slot)
    }

    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_instruction_processor(
        &mut self,
        program_id: Pubkey,
        process_instruction: ProcessInstruction,
    ) {
        self.message_processor
            .add_instruction_processor(program_id, process_instruction);

        if let Some(program_account) = self.get_account(&program_id) {
            // It is not valid to intercept instructions for a non-native loader account
            assert_eq!(program_account.owner, solana_sdk::native_loader::id());
        } else {
            // Register a bogus executable account, which will be loaded and ignored.
            self.register_native_instruction_processor("", &program_id);
        }
    }

    pub fn compare_bank(&self, dbank: &Bank) {
        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 st = self.stakes.read().unwrap();
        let dst = dbank.stakes.read().unwrap();
        assert_eq!(*st, *dst);

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

        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();
    }
}

impl Drop for Bank {
    fn drop(&mut self) {
        // For root slots this is a noop
        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;
        }
    }
}

// This guards against possible memory exhaustions in bincode when restoring
// the full state from snapshot data files by imposing a fixed hard limit with
// ample of headrooms for such a usecase.
pub fn deserialize_from_snapshot<R, T>(reader: R) -> bincode::Result<T>
where
    R: Read,
    T: serde::de::DeserializeOwned,
{
    bincode::config()
        .limit(MAX_SNAPSHOT_DATA_FILE_SIZE)
        .deserialize_from(reader)
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::{
        accounts_db::{get_temp_accounts_paths, tests::copy_append_vecs},
        genesis_utils::{
            create_genesis_config_with_leader, GenesisConfigInfo, BOOTSTRAP_VALIDATOR_LAMPORTS,
        },
        status_cache::MAX_CACHE_ENTRIES,
    };
    use bincode::{serialize_into, serialized_size};
    use solana_sdk::{
        account::KeyedAccount,
        account_utils::StateMut,
        clock::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::{self, solana_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::{io::Cursor, result, time::Duration};
    use tempfile::TempDir;

    #[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]
    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().map(|k| *k).collect();
                keys.sort();
                keys
            }

            fn epoch_stake_key_info(&self) -> (Epoch, Epoch, usize) {
                let mut keys: Vec<Epoch> = self.epoch_stakes.keys().map(|k| *k).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)
                .into_iter()
                .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_bank_inflation() {
        let key = Pubkey::default();
        let bank = Arc::new(Bank::new(&GenesisConfig {
            accounts: (0..42)
                .into_iter()
                .map(|_| (Pubkey::new_rand(), Account::new(42, 0, &key)))
                .collect(),
            ..GenesisConfig::default()
        }));
        assert_eq!(bank.capitalization(), 42 * 42);

        // With inflation
        bank.set_entered_epoch_callback(Box::new(move |bank: &mut Bank| {
            let mut inflation = Inflation::default();
            inflation.initial = 1_000_000.0;
            bank.set_inflation(inflation)
        }));
        let bank1 = Bank::new_from_parent(&bank, &key, MINIMUM_SLOTS_PER_EPOCH + 1);
        assert_ne!(bank.capitalization(), bank1.capitalization());

        // Without inflation
        bank.set_entered_epoch_callback(Box::new(move |bank: &mut Bank| {
            bank.set_inflation(Inflation::new_disabled())
        }));
        let bank2 = Bank::new_from_parent(&bank, &key, MINIMUM_SLOTS_PER_EPOCH * 2 + 1);
        assert_eq!(bank.capitalization(), bank2.capitalization());
    }

    #[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 = solana_system_program().1;
        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(&vec![t1.clone(), t2.clone(), t3.clone()]);

        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(&vec![t2.clone(), t1.clone()]);

        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(
            vec![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_instruction_processor(mock_program_id, mock_process_instruction);

        let system_program_id = solana_system_program().1;
        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
    }

    #[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]
    #[allow(clippy::cognitive_complexity)]
    fn test_rent_complex() {
        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 = Arc::new(Bank::new(&genesis_config));
        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.clone(),
            t5.clone(),
            t1.clone(),
            t2.clone(),
            t3.clone(),
            t4.clone(),
        ]);

        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_bank_update_rewards() {
        // create a bank that ticks really slowly...
        let bank = Arc::new(Bank::new(&GenesisConfig {
            accounts: (0..42)
                .into_iter()
                .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()
        }));
        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);

        let ((validator_id, validator_account), (archiver_id, archiver_account)) =
            crate::storage_utils::tests::create_storage_accounts_with_credits(100);

        // set up stakes, vote, and storage accounts
        bank.store_account(&stake_id, &stake_account);
        bank.store_account(&validator_id, &validator_account);
        bank.store_account(&archiver_id, &archiver_account);

        // generate some rewards
        let mut vote_state = Some(VoteState::from(&vote_account).unwrap());
        for i in 0..MAX_LOCKOUT_HISTORY + 42 {
            vote_state
                .as_mut()
                .map(|v| 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 = bank.stakes.read().unwrap().points();
        let storage_points = bank.storage_accounts.read().unwrap().points();

        // 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
                + rewards.storage_point_value * storage_points as f64)
                - inflation as f64)
                .abs()
                < 1.0 // rounding, truncating
        );

        // verify validator rewards show up in bank1.rewards vector
        // (currently storage rewards will not show up)
        assert_eq!(
            bank1.rewards,
            Some(vec![(
                stake_id,
                (rewards.validator_point_value * validator_points as f64) as i64
            )])
        );
    }

    // 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(&vec![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 tx = Transaction::new_signed_instructions(
            &[&mint_keypair],
            instructions,
            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 tx = Transaction::new_signed_instructions(
            &[&mint_keypair],
            instructions,
            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() {
        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_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(&vec![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(
            vec![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(
            vec![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.clone());
        let tx0 = Transaction::new_signed_with_payer(
            vec![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_RECENT_BLOCKHASHES, 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::InvalidAccountIndex)
        );

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

    #[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);

        // TODO: Why do we convert errors to Oks?
        //res[0].clone().unwrap_err();

        bank.get_signature_status(&tx.signatures[0])
            .unwrap()
            .unwrap_err();
    }

    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.clone(), &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();
        //let added_bank_hash = BankHash::from_hash(&current_account.hash);
        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 tx = Transaction::new_signed_instructions(
            &Vec::<&Keypair>::new(),
            vec![transfer_instruction],
            bank.last_blockhash(),
        );

        assert_eq!(bank.process_transaction(&tx), Ok(()));
        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 transaction = Transaction::new_signed_instructions(
            &[&mint_keypair, &vote_keypair],
            instructions,
            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 transaction = Transaction::new_signed_instructions(
            &[&mint_keypair, &vote_keypair, &stake_keypair],
            instructions,
            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_serialize() {
        solana_logger::setup();
        let (genesis_config, _) = create_genesis_config(500);
        let bank0 = Arc::new(Bank::new(&genesis_config));
        let bank1 = Bank::new_from_parent(&bank0, &Pubkey::default(), 1);
        bank0.squash();

        // Create an account on a non-root fork
        let key1 = Keypair::new();
        bank1.deposit(&key1.pubkey(), 5);

        let bank2 = Bank::new_from_parent(&bank0, &Pubkey::default(), 2);

        // Test new account
        let key2 = Keypair::new();
        bank2.deposit(&key2.pubkey(), 10);
        assert_eq!(bank2.get_balance(&key2.pubkey()), 10);

        let key3 = Keypair::new();
        bank2.deposit(&key3.pubkey(), 0);

        bank2.squash();

        let snapshot_storages = bank2.get_snapshot_storages();
        let rc_serialize = BankRcSerialize {
            bank_rc: &bank2.rc,
            snapshot_storages: &snapshot_storages,
        };
        let len = serialized_size(&bank2).unwrap() + serialized_size(&rc_serialize).unwrap();
        let mut buf = vec![0u8; len as usize];
        let mut writer = Cursor::new(&mut buf[..]);
        serialize_into(&mut writer, &bank2).unwrap();
        serialize_into(&mut writer, &rc_serialize).unwrap();

        let mut rdr = Cursor::new(&buf[..]);
        let mut dbank: Bank = deserialize_from_snapshot(&mut rdr).unwrap();
        let mut reader = BufReader::new(&buf[rdr.position() as usize..]);

        // Create a new set of directories for this bank's accounts
        let (_accounts_dir, dbank_paths) = get_temp_accounts_paths(4).unwrap();
        let ref_sc = StatusCacheRc::default();
        ref_sc.status_cache.write().unwrap().add_root(2);
        dbank.set_bank_rc(BankRc::new(dbank_paths.clone(), 0, dbank.slot()), ref_sc);
        // Create a directory to simulate AppendVecs unpackaged from a snapshot tar
        let copied_accounts = TempDir::new().unwrap();
        copy_append_vecs(&bank2.rc.accounts.accounts_db, copied_accounts.path()).unwrap();
        dbank
            .rc
            .accounts_from_stream(&mut reader, &dbank_paths, copied_accounts.path())
            .unwrap();
        assert_eq!(dbank.get_balance(&key1.pubkey()), 0);
        assert_eq!(dbank.get_balance(&key2.pubkey()), 10);
        assert_eq!(dbank.get_balance(&key3.pubkey()), 0);
        bank2.compare_bank(&dbank);
    }

    #[test]
    fn test_check_point_values() {
        let (genesis_config, _) = create_genesis_config(500);
        let bank = Arc::new(Bank::new(&genesis_config));

        // check that point values are 0 if no previous value was known and current values are not normal
        assert_eq!(
            bank.check_point_values(std::f64::INFINITY, std::f64::NAN),
            (0.0, 0.0)
        );

        bank.store_account(
            &sysvar::rewards::id(),
            &sysvar::rewards::create_account(1, 1.0, 1.0),
        );
        // check that point values are the previous value if current values are not normal
        assert_eq!(
            bank.check_point_values(std::f64::INFINITY, std::f64::NAN),
            (1.0, 1.0)
        );
    }

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

        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.clone())]
        );
        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_instruction_processor() {
        let (genesis_config, mint_keypair) = create_genesis_config(500);
        let mut bank = Bank::new(&genesis_config);

        fn mock_vote_processor(
            program_id: &Pubkey,
            _keyed_accounts: &[KeyedAccount],
            _instruction_data: &[u8],
        ) -> std::result::Result<(), InstructionError> {
            if !solana_vote_program::check_id(program_id) {
                return Err(InstructionError::IncorrectProgramId);
            }
            Err(InstructionError::CustomError(42))
        }

        assert!(bank.get_account(&solana_vote_program::id()).is_none());
        bank.add_instruction_processor(solana_vote_program::id(), mock_vote_processor);
        assert!(bank.get_account(&solana_vote_program::id()).is_some());

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

        let transaction = Transaction::new_signed_instructions(
            &[&mint_keypair, &mock_account],
            instructions,
            bank.last_blockhash(),
        );

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

    #[test]
    fn test_add_instruction_processor_for_existing_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::CustomError(42))
        }

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

        let transaction = Transaction::new_signed_instructions(
            &[&mint_keypair, &mock_account],
            instructions,
            bank.last_blockhash(),
        );

        let vote_loader_account = bank.get_account(&solana_vote_program::id()).unwrap();
        bank.add_instruction_processor(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::CustomError(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::CustomError(42))
        }

        // Non-native loader accounts can not be used for instruction processing
        bank.add_instruction_processor(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().nth(0).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_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(nonce_keypair.pubkey());
        setup_ixs.extend_from_slice(&system_instruction::create_nonce_account(
            &custodian_keypair.pubkey(),
            &nonce_keypair.pubkey(),
            &nonce_authority,
            nonce_lamports,
        ));
        let setup_tx = Transaction::new_signed_instructions(
            &[mint_keypair, &custodian_keypair, &nonce_keypair],
            setup_ixs,
            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(
            vec![
                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(
            vec![
                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(
            vec![
                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(
            vec![
                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(
            vec![
                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(
            42424242,
            &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 tx = Transaction::new_signed_instructions(
            &[&nonce],
            vec![system_instruction::assign(
                &nonce.pubkey(),
                &Pubkey::new(&[9u8; 32]),
            )],
            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,
            |gc| {
                gc.rent.lamports_per_byte_year;
            },
            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(
            vec![
                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(
            vec![
                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(
            vec![
                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_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 balances = bank0.collect_balances(&[tx0, tx1]);
        assert_eq!(balances.len(), 2);
        assert_eq!(balances[0], vec![8, 11, 1]);
        assert_eq!(balances[1], vec![8, 0, 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.clone());
        let tx1 = system_transaction::transfer(&Keypair::new(), &pubkey1, 2, blockhash.clone());
        let tx2 = system_transaction::transfer(&keypair1, &pubkey2, 12, blockhash.clone());
        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_RECENT_BLOCKHASHES, 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_instruction_processor(mock_program_id, mock_process_instruction);

        let from_pubkey = Pubkey::new_rand();
        let to_pubkey = Pubkey::new_rand();
        let dup_pubkey = from_pubkey.clone();
        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(
            vec![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_instruction_processor(mock_program_id, mock_process_instruction);

        let from_pubkey = Pubkey::new_rand();
        let to_pubkey = Pubkey::new_rand();
        let dup_pubkey = from_pubkey.clone();
        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(
            vec![instruction],
            Some(&mint_keypair.pubkey()),
            &[&mint_keypair],
            bank.last_blockhash(),
        );

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