Struct ChainLock 

pub struct ChainLock<T: Transaction> { /* private fields */ }

Environment-independent chain lock interface and protocol.

Implementations

impl<T: Transaction> ChainLock<T>

pub const fn new() -> Self

Creates a new unlocked ChainLock.

pub fn acquire_first_in_chain(&self, token: &ChainLockTransactionToken<T>)

Acquires the lock without backoff, spinning until acquired. This method may be used for the first chain lock acquired in a transaction as an optimization, since backoff is unnecessary when no other chain locks are held.

Asserts if a cycle is detected or if any chain locks are currently held.

pub fn acquire_or_backoff(&self, token: &ChainLockTransactionToken<T>) -> bool

Acquires the lock, spinning until acquired or returning failure because the caller should back off due to contention with a higher priority transaction. Returns true if the lock was acquired or false if the current transaction should back off. Asserts if a cycle is detected.

pub fn acquire_or_result( &self, token: &ChainLockTransactionToken<T>, ) -> Result<(), Result>

Acquires the lock, spinning until acquired or returning Err with Result::Backoff or Result::Cycle. Returns Ok(()) if the lock was acquired or Err(result) if acquiring the lock failed.

pub fn try_acquire(&self, token: &ChainLockTransactionToken<T>) -> bool

Attempts to acquire the lock with default options (AllowFinalized::No, RecordBackoff::Yes). Returns true if the lock was acquired or false if acquiring the lock failed. Asserts if a cycle is detected.

pub fn try_acquire_with_options( &self, allow_finalized: AllowFinalized, record_backoff: RecordBackoff, token: &ChainLockTransactionToken<T>, ) -> bool

Attempts to acquire the lock with the specified allow_finalized and record_backoff options. Returns true if the lock was acquired or false if acquiring the lock failed. Asserts if a cycle is detected.

pub fn release(&self, token: &ChainLockTransactionToken<T>)

Releases the lock.

pub fn assert_held(&self, token: &ChainLockTransactionToken<T>)

Asserts in debug builds that the lock is held by the current transaction.

pub fn assert_acquired(&self, token: &ChainLockTransactionToken<T>)

Asserts in debug builds that the lock is held by the current transaction and must be released by the caller’s scope.

pub fn is_held(&self, token: &ChainLockTransactionToken<T>) -> bool

Returns true if the lock is held by the current transaction.

pub fn is_unlocked(&self) -> bool

Returns true if the lock is unlocked.

pub fn sync_token(&self, token: &ChainLockTransactionToken<T>)

Syncs the held token value of this lock with the current transaction token. Used for saving and restoring state in special circumstances that use reserved tokens.

pub fn state_for_testing(&self) -> Token

Returns the currently stored Token of this lock with Relaxed memory ordering for testing.

Trait Implementations

impl<T: Transaction> Default for ChainLock<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Transaction> Drop for ChainLock<T>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.