Expand description
An RAII mutex guard returned by MutexGuard::map
, which can point to a
subfield of the protected data.
The main difference between MappedMutexGuard
and MutexGuard
is that the
former doesn’t support temporarily unlocking and re-locking, since that
could introduce soundness issues if the locked object is modified by another
thread.
Implementations
impl<'a, R, T> MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<'a, R, T> MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + ?Sized,
pub fn map<U, F>(
s: MappedMutexGuard<'a, R, T>,
f: F
) -> MappedMutexGuard<'a, R, U> where
F: FnOnce(&mut T) -> &mut U,
U: ?Sized,
pub fn map<U, F>(
s: MappedMutexGuard<'a, R, T>,
f: F
) -> MappedMutexGuard<'a, R, U> where
F: FnOnce(&mut T) -> &mut U,
U: ?Sized,
Makes a new MappedMutexGuard
for a component of the locked data.
This operation cannot fail as the MappedMutexGuard
passed
in already locked the mutex.
This is an associated function that needs to be
used as MappedMutexGuard::map(...)
. A method would interfere with methods of
the same name on the contents of the locked data.
pub fn try_map<U, F>(
s: MappedMutexGuard<'a, R, T>,
f: F
) -> Result<MappedMutexGuard<'a, R, U>, MappedMutexGuard<'a, R, T>> where
F: FnOnce(&mut T) -> Option<&mut U>,
U: ?Sized,
pub fn try_map<U, F>(
s: MappedMutexGuard<'a, R, T>,
f: F
) -> Result<MappedMutexGuard<'a, R, U>, MappedMutexGuard<'a, R, T>> where
F: FnOnce(&mut T) -> Option<&mut U>,
U: ?Sized,
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 MappedMutexGuard
passed
in already locked the mutex.
This is an associated function that needs to be
used as MappedMutexGuard::try_map(...)
. A method would interfere with methods of
the same name on the contents of the locked data.
impl<'a, R, T> MappedMutexGuard<'a, R, T> where
R: 'a + RawMutexFair,
T: 'a + ?Sized,
impl<'a, R, T> MappedMutexGuard<'a, R, T> where
R: 'a + RawMutexFair,
T: 'a + ?Sized,
pub fn unlock_fair(s: MappedMutexGuard<'a, R, T>)
pub fn unlock_fair(s: MappedMutexGuard<'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.
Trait Implementations
impl<'a, R, T> Debug for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + Debug + ?Sized,
impl<'a, R, T> Debug for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + Debug + ?Sized,
impl<'a, R, T> Deref for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<'a, R, T> Deref for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<'a, R, T> DerefMut for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<'a, R, T> DerefMut for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<'a, R, T> Display for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + Display + ?Sized,
impl<'a, R, T> Display for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + Display + ?Sized,
impl<'a, R, T> Drop for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<'a, R, T> Drop for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + ?Sized,
impl<'a, R, T> Send for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex,
T: 'a + Send + ?Sized,
<R as RawMutex>::GuardMarker: Send,
impl<'a, R, T> Sync for MappedMutexGuard<'a, R, T> where
R: 'a + RawMutex + Sync,
T: 'a + Sync + ?Sized,
Auto Trait Implementations
impl<'a, R, T: ?Sized> RefUnwindSafe for MappedMutexGuard<'a, R, T> where
R: RefUnwindSafe,
T: RefUnwindSafe,
impl<'a, R, T: ?Sized> Unpin for MappedMutexGuard<'a, R, T>
impl<'a, R, T> !UnwindSafe for MappedMutexGuard<'a, R, T>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
fn instrument(self, span: Span) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
T: Future, type Output = <T as Future>::Output;
sourcefn in_current_span(self) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
fn in_current_span(self) -> Instrumented<Self>ⓘNotable traits for Instrumented<T>impl<T> Future for Instrumented<T> where
T: Future, type Output = <T as Future>::Output;
T: Future, type Output = <T as Future>::Output;
impl<T> Pointable for T
impl<T> Pointable for T
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
fn vzip(self) -> V
sourceimpl<T> WithSubscriber for T
impl<T> WithSubscriber for T
sourcefn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
where
S: Into<Dispatch>,
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
where
S: Into<Dispatch>,
T: Future, type Output = <T as Future>::Output;
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
sourcefn with_current_subscriber(self) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
fn with_current_subscriber(self) -> WithDispatch<Self>ⓘNotable traits for WithDispatch<T>impl<T> Future for WithDispatch<T> where
T: Future, type Output = <T as Future>::Output;
T: Future, type Output = <T as Future>::Output;
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more