Type Alias parking_lot::MutexGuard
source · pub type MutexGuard<'a, T> = MutexGuard<'a, RawMutex, T>;
Expand description
An RAII implementation of a “scoped lock” of a mutex. When this structure is dropped (falls out of scope), the lock will be unlocked.
The data protected by the mutex can be accessed through this guard via its
Deref
and DerefMut
implementations.
Aliased Type§
struct MutexGuard<'a, T> { /* private fields */ }
Implementations
source§impl<'a, R, T> MutexGuard<'a, R, T>
impl<'a, R, T> MutexGuard<'a, R, T>
sourcepub fn mutex(s: &MutexGuard<'a, R, T>) -> &'a Mutex<R, T>
pub fn mutex(s: &MutexGuard<'a, R, T>) -> &'a Mutex<R, T>
Returns a reference to the original Mutex
object.
sourcepub fn map<U, F>(s: MutexGuard<'a, R, T>, f: F) -> MappedMutexGuard<'a, R, U>
pub fn map<U, F>(s: MutexGuard<'a, R, T>, f: F) -> MappedMutexGuard<'a, R, U>
Makes a new MappedMutexGuard
for a component of the locked data.
This operation cannot fail as the MutexGuard
passed
in already locked the mutex.
This is an associated function that needs to be
used as MutexGuard::map(...)
. A method would interfere with methods of
the same name on the contents of the locked data.
sourcepub fn try_map<U, F>(
s: MutexGuard<'a, R, T>,
f: F,
) -> Result<MappedMutexGuard<'a, R, U>, MutexGuard<'a, R, T>>
pub fn try_map<U, F>( s: MutexGuard<'a, R, T>, f: F, ) -> Result<MappedMutexGuard<'a, R, U>, MutexGuard<'a, R, T>>
Attempts to make a new MappedMutexGuard
for a component of the
locked data. The original guard is returned if the closure returns None
.
This operation cannot fail as the MutexGuard
passed
in already locked the mutex.
This is an associated function that needs to be
used as MutexGuard::try_map(...)
. A method would interfere with methods of
the same name on the contents of the locked data.
sourcepub fn unlocked<F, U>(s: &mut MutexGuard<'a, R, T>, f: F) -> Uwhere
F: FnOnce() -> U,
pub fn unlocked<F, U>(s: &mut MutexGuard<'a, R, T>, f: F) -> Uwhere
F: FnOnce() -> U,
Temporarily unlocks the mutex to execute the given function.
This is safe because &mut
guarantees that there exist no other
references to the data protected by the mutex.
sourcepub fn leak(s: MutexGuard<'a, R, T>) -> &'a mut T
pub fn leak(s: MutexGuard<'a, R, T>) -> &'a mut T
Leaks the mutex guard and returns a mutable reference to the data protected by the mutex.
This will leave the Mutex
in a locked state.
source§impl<'a, R, T> MutexGuard<'a, R, T>where
R: RawMutexFair + 'a,
T: 'a + ?Sized,
impl<'a, R, T> MutexGuard<'a, R, T>where
R: RawMutexFair + 'a,
T: 'a + ?Sized,
sourcepub fn unlock_fair(s: MutexGuard<'a, R, T>)
pub fn unlock_fair(s: MutexGuard<'a, R, T>)
Unlocks the mutex using a fair unlock protocol.
By default, mutexes are unfair and allow the current thread to re-lock the mutex before another has the chance to acquire the lock, even if that thread has been blocked on the mutex for a long time. This is the default because it allows much higher throughput as it avoids forcing a context switch on every mutex unlock. This can result in one thread acquiring a mutex 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 MutexGuard
normally.
sourcepub fn unlocked_fair<F, U>(s: &mut MutexGuard<'a, R, T>, f: F) -> Uwhere
F: FnOnce() -> U,
pub fn unlocked_fair<F, U>(s: &mut MutexGuard<'a, R, T>, f: F) -> Uwhere
F: FnOnce() -> U,
Temporarily unlocks the mutex to execute the given function.
The mutex is unlocked using a fair unlock protocol.
This is safe because &mut
guarantees that there exist no other
references to the data protected by the mutex.
sourcepub fn bump(s: &mut MutexGuard<'a, R, T>)
pub fn bump(s: &mut MutexGuard<'a, R, T>)
Temporarily yields the mutex to a waiting thread if there is one.
This method is functionally equivalent to calling unlock_fair
followed
by lock
, however it can be much more efficient in the case where there
are no waiting threads.