Struct lock_api::RwLockReadGuard
source · [−]Expand description
RAII structure used to release the shared read access of a lock when dropped.
Implementations
Returns a reference to the original reader-writer lock object.
Make a new MappedRwLockReadGuard
for a component of the locked data.
This operation cannot fail as the RwLockReadGuard
passed
in already locked the data.
This is an associated function that needs to be
used as RwLockReadGuard::map(...)
. A method would interfere with methods of
the same name on the contents of the locked data.
Attempts to make a new MappedRwLockReadGuard
for a component of the
locked data. The original guard is return if the closure returns None
.
This operation cannot fail as the RwLockReadGuard
passed
in already locked the data.
This is an associated function that needs to be
used as RwLockReadGuard::map(...)
. A method would interfere with methods of
the same name on the contents of the locked data.
Unlocks the RwLock
using a fair unlock protocol.
By default, RwLock
is unfair and allow the current thread to re-lock
the RwLock
before another has the chance to acquire the lock, even if
that thread has been blocked on the RwLock
for a long time. This is
the default because it allows much higher throughput as it avoids
forcing a context switch on every RwLock
unlock. This can result in one
thread acquiring a RwLock
many more times than other threads.
However in some cases it can be beneficial to ensure fairness by forcing
the lock to pass on to a waiting thread if there is one. This is done by
using this method instead of dropping the RwLockReadGuard
normally.
Temporarily unlocks the RwLock
to execute the given function.
The RwLock
is unlocked a fair unlock protocol.
This is safe because &mut
guarantees that there exist no other
references to the data protected by the RwLock
.