Trait lock_api::RawRwLockFair

pub unsafe trait RawRwLockFair: RawRwLock {
    unsafe fn unlock_shared_fair(&self);
    unsafe fn unlock_exclusive_fair(&self);

    unsafe fn bump_shared(&self) { ... }
    unsafe fn bump_exclusive(&self) { ... }
}

Additional methods for RwLocks which support fair unlocking.

Fair unlocking means that a lock is handed directly over to the next waiting thread if there is one, without giving other threads the opportunity to “steal” the lock in the meantime. This is typically slower than unfair unlocking, but may be necessary in certain circumstances.

Required methods

unsafe fn unlock_shared_fair(&self)

Releases a shared lock using a fair unlock protocol.

Safety

This method may only be called if a shared lock is held in the current context.

unsafe fn unlock_exclusive_fair(&self)

Releases an exclusive lock using a fair unlock protocol.

Safety

This method may only be called if an exclusive lock is held in the current context.

Provided methods

unsafe fn bump_shared(&self)

Temporarily yields a shared lock to a waiting thread if there is one.

This method is functionally equivalent to calling unlock_shared_fair followed by lock_shared, however it can be much more efficient in the case where there are no waiting threads.

Safety

This method may only be called if a shared lock is held in the current context.

unsafe fn bump_exclusive(&self)

Temporarily yields an exclusive lock to a waiting thread if there is one.

This method is functionally equivalent to calling unlock_exclusive_fair followed by lock_exclusive, however it can be much more efficient in the case where there are no waiting threads.

Safety

This method may only be called if an exclusive lock is held in the current context.

Implementors