Struct lock_api::MappedRwLockWriteGuard
source · [−]Expand description
An RAII write lock guard returned by RwLockWriteGuard::map
, which can point to a
subfield of the protected data.
The main difference between MappedRwLockWriteGuard
and RwLockWriteGuard
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
sourceimpl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> MappedRwLockWriteGuard<'a, R, T>
impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> MappedRwLockWriteGuard<'a, R, T>
sourcepub fn map<U: ?Sized, F>(s: Self, f: F) -> MappedRwLockWriteGuard<'a, R, U> where
F: FnOnce(&mut T) -> &mut U,
pub fn map<U: ?Sized, F>(s: Self, f: F) -> MappedRwLockWriteGuard<'a, R, U> where
F: FnOnce(&mut T) -> &mut U,
Make a new MappedRwLockWriteGuard
for a component of the locked data.
This operation cannot fail as the MappedRwLockWriteGuard
passed
in already locked the data.
This is an associated function that needs to be
used as MappedRwLockWriteGuard::map(...)
. A method would interfere with methods of
the same name on the contents of the locked data.
sourcepub fn try_map<U: ?Sized, F>(
s: Self,
f: F
) -> Result<MappedRwLockWriteGuard<'a, R, U>, Self> where
F: FnOnce(&mut T) -> Option<&mut U>,
pub fn try_map<U: ?Sized, F>(
s: Self,
f: F
) -> Result<MappedRwLockWriteGuard<'a, R, U>, Self> where
F: FnOnce(&mut T) -> Option<&mut U>,
Attempts to make a new MappedRwLockWriteGuard
for a component of the
locked data. The original guard is return if the closure returns None
.
This operation cannot fail as the MappedRwLockWriteGuard
passed
in already locked the data.
This is an associated function that needs to be
used as MappedRwLockWriteGuard::map(...)
. A method would interfere with methods of
the same name on the contents of the locked data.
sourceimpl<'a, R: RawRwLockFair + 'a, T: ?Sized + 'a> MappedRwLockWriteGuard<'a, R, T>
impl<'a, R: RawRwLockFair + 'a, T: ?Sized + 'a> MappedRwLockWriteGuard<'a, R, T>
sourcepub fn unlock_fair(s: Self)
pub fn unlock_fair(s: Self)
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 MappedRwLockWriteGuard
normally.
Trait Implementations
sourceimpl<'a, R: RawRwLock + 'a, T: Debug + ?Sized + 'a> Debug for MappedRwLockWriteGuard<'a, R, T>
impl<'a, R: RawRwLock + 'a, T: Debug + ?Sized + 'a> Debug for MappedRwLockWriteGuard<'a, R, T>
sourceimpl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> Deref for MappedRwLockWriteGuard<'a, R, T>
impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> Deref for MappedRwLockWriteGuard<'a, R, T>
sourceimpl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> DerefMut for MappedRwLockWriteGuard<'a, R, T>
impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> DerefMut for MappedRwLockWriteGuard<'a, R, T>
sourceimpl<'a, R: RawRwLock + 'a, T: Display + ?Sized + 'a> Display for MappedRwLockWriteGuard<'a, R, T>
impl<'a, R: RawRwLock + 'a, T: Display + ?Sized + 'a> Display for MappedRwLockWriteGuard<'a, R, T>
sourceimpl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> Drop for MappedRwLockWriteGuard<'a, R, T>
impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> Drop for MappedRwLockWriteGuard<'a, R, T>
impl<'a, R: RawRwLock + 'a, T: ?Sized + Send + 'a> Send for MappedRwLockWriteGuard<'a, R, T> where
R::GuardMarker: Send,
impl<'a, R: RawRwLock + 'a, T: ?Sized + Sync + 'a> Sync for MappedRwLockWriteGuard<'a, R, T>
Auto Trait Implementations
impl<'a, R, T: ?Sized> RefUnwindSafe for MappedRwLockWriteGuard<'a, R, T> where
R: RefUnwindSafe,
T: RefUnwindSafe,
impl<'a, R, T: ?Sized> Unpin for MappedRwLockWriteGuard<'a, R, T>
impl<'a, R, T> !UnwindSafe for MappedRwLockWriteGuard<'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