add some doc comments identified in audit (#32709)

* add some doc comments identified in audit

* Update runtime/src/bank.rs

Co-authored-by: Brooks <brooks@prumo.org>

* Update runtime/src/accounts_db.rs

Co-authored-by: Brooks <brooks@prumo.org>

* Update runtime/src/accounts_db.rs

Co-authored-by: Brooks <brooks@prumo.org>

---------

Co-authored-by: Brooks <brooks@prumo.org>

runtime/src/accounts_db.rs

@@ -5008,6 +5008,8 @@ impl AccountsDb {
         account_accessor.account_matches_owners(owners)
     }
 
+    /// load the account with `pubkey` into the read only accounts cache.
+    /// The goal is to make subsequent loads (which caller expects to occur) to find the account quickly.
     pub fn load_account_into_read_cache(&self, ancestors: &Ancestors, pubkey: &Pubkey) {
         self.do_load_with_populate_read_cache(
             ancestors,
@@ -6987,6 +6989,8 @@ impl AccountsDb {
         Ok((accounts_hash, total_lamports))
     }
 
+    /// This is only valid to call from tests.
+    /// run the accounts hash calculation and store the results
     pub fn update_accounts_hash_for_tests(
         &self,
         slot: Slot,
@@ -7311,6 +7315,7 @@ impl AccountsDb {
         Ok((accounts_hash, total_lamports))
     }
 
+    /// run the accounts hash calculation and store the results
     #[allow(clippy::too_many_arguments)]
     pub fn update_accounts_hash(
         &self,

runtime/src/bank.rs

@@ -404,9 +404,13 @@ impl TransactionLogCollector {
     }
 }
 
-// Bank's common fields shared by all supported snapshot versions for deserialization.
+/// Bank's common fields shared by all supported snapshot versions for deserialization.
-// Sync fields with BankFieldsToSerialize! This is paired with it.
+/// Sync fields with BankFieldsToSerialize! This is paired with it.
-// All members are made public to remain Bank's members private and to make versioned deserializer workable on this
+/// All members are made public to remain Bank's members private and to make versioned deserializer workable on this
+/// Note that some fields are missing from the serializer struct. This is because of fields added later.
+/// Since it is difficult to insert fields to serialize/deserialize against existing code already deployed,
+/// new fields can be optionally serialized and optionally deserialized. At some point, the serialization and
+/// deserialization will use a new mechanism or otherwise be in sync more clearly.
 #[derive(Clone, Debug, Default, PartialEq)]
 pub struct BankFieldsToDeserialize {
     pub(crate) blockhash_queue: BlockhashQueue,
@@ -445,10 +449,14 @@ pub struct BankFieldsToDeserialize {
     pub(crate) epoch_reward_status: EpochRewardStatus,
 }
 
-// Bank's common fields shared by all supported snapshot versions for serialization.
+/// Bank's common fields shared by all supported snapshot versions for serialization.
-// This is separated from BankFieldsToDeserialize to avoid cloning by using refs.
+/// This is separated from BankFieldsToDeserialize to avoid cloning by using refs.
-// So, sync fields with BankFieldsToDeserialize!
+/// So, sync fields with BankFieldsToDeserialize!
-// all members are made public to keep Bank private and to make versioned serializer workable on this
+/// all members are made public to keep Bank private and to make versioned serializer workable on this.
+/// Note that some fields are missing from the serializer struct. This is because of fields added later.
+/// Since it is difficult to insert fields to serialize/deserialize against existing code already deployed,
+/// new fields can be optionally serialized and optionally deserialized. At some point, the serialization and
+/// deserialization will use a new mechanism or otherwise be in sync more clearly.
 #[derive(Debug)]
 pub(crate) struct BankFieldsToSerialize<'a> {
     pub(crate) blockhash_queue: &'a RwLock<BlockhashQueue>,
@@ -989,6 +997,8 @@ impl Bank {
         )
     }
 
+    /// Intended for use by tests only.
+    /// create new bank with the given configs.
     pub fn new_with_runtime_config_for_tests(
         genesis_config: &GenesisConfig,
         runtime_config: Arc<RuntimeConfig>,
@@ -1115,6 +1125,8 @@ impl Bank {
         )
     }
 
+    /// Intended for use by benches only.
+    /// create new bank with the given config and paths.
     pub fn new_with_paths_for_benches(genesis_config: &GenesisConfig, paths: Vec<PathBuf>) -> Self {
         Self::new_with_paths(
             genesis_config,
@@ -3756,6 +3768,9 @@ impl Bank {
 
     /// squash the parent's state up into this Bank,
     ///   this Bank becomes a root
+    /// Note that this function is not thread-safe. If it is called concurrently on the same bank
+    /// by multiple threads, the end result could be inconsistent.
+    /// Calling code does not currently call this concurrently.
     pub fn squash(&self) -> SquashTiming {
         self.freeze();
 
@@ -4028,6 +4043,7 @@ impl Bank {
         Some(self.get_fee_for_message_with_lamports_per_signature(message, lamports_per_signature))
     }
 
+    /// Returns true when startup accounts hash verification has completed or never had to run in background.
     pub fn get_startup_verification_complete(&self) -> &Arc<AtomicBool> {
         &self
             .rc
@@ -4037,6 +4053,9 @@ impl Bank {
             .verified
     }
 
+    /// return true if bg hash verification is complete
+    /// return false if bg hash verification has not completed yet
+    /// if hash verification failed, a panic will occur
     pub fn is_startup_verification_complete(&self) -> bool {
         self.rc
             .accounts
@@ -6478,6 +6497,8 @@ impl Bank {
         parents
     }
 
+    /// fn store the single `account` with `pubkey`.
+    /// Uses `store_accounts`, which works on a vector of accounts.
     pub fn store_account<T: ReadableAccount + Sync + ZeroLamport>(
         &self,
         pubkey: &Pubkey,
@@ -7040,6 +7061,8 @@ impl Bank {
         epoch_accounts_hash
     }
 
+    /// Used by ledger tool to run a final hash calculation once all ledger replay has completed.
+    /// This should not be called by validator code.
     pub fn run_final_hash_calc(&self, on_halt_store_hash_raw_data_for_debug: bool) {
         self.force_flush_accounts_cache();
         // note that this slot may not be a root
@@ -7174,6 +7197,8 @@ impl Bank {
             .check_complete()
     }
 
+    /// This is only valid to call from tests.
+    /// block until initial accounts hash verification has completed
     pub fn wait_for_initial_accounts_hash_verification_completed_for_tests(&self) {
         self.rc
             .accounts
@@ -7545,6 +7570,7 @@ impl Bank {
         *self.inflation.read().unwrap()
     }
 
+    /// Return the rent collector for this Bank
     pub fn rent_collector(&self) -> &RentCollector {
         &self.rent_collector
     }