Struct lock_api::RwLockReadGuard
source · [−]Expand description
RAII structure used to release the shared read access of a lock when dropped.
Implementations
sourceimpl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> RwLockReadGuard<'a, R, T>
impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> RwLockReadGuard<'a, R, T>
sourcepub fn rwlock(s: &Self) -> &'a RwLock<R, T>
pub fn rwlock(s: &Self) -> &'a RwLock<R, T>
Returns a reference to the original reader-writer lock object.
sourcepub fn map<U: ?Sized, F>(s: Self, f: F) -> MappedRwLockReadGuard<'a, R, U> where
F: FnOnce(&T) -> &U,
pub fn map<U: ?Sized, F>(s: Self, f: F) -> MappedRwLockReadGuard<'a, R, U> where
F: FnOnce(&T) -> &U,
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.
sourcepub fn try_map<U: ?Sized, F>(
s: Self,
f: F
) -> Result<MappedRwLockReadGuard<'a, R, U>, Self> where
F: FnOnce(&T) -> Option<&U>,
pub fn try_map<U: ?Sized, F>(
s: Self,
f: F
) -> Result<MappedRwLockReadGuard<'a, R, U>, Self> where
F: FnOnce(&T) -> Option<&U>,
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.
sourceimpl<'a, R: RawRwLockFair + 'a, T: ?Sized + 'a> RwLockReadGuard<'a, R, T>
impl<'a, R: RawRwLockFair + 'a, T: ?Sized + 'a> RwLockReadGuard<'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 RwLockReadGuard
normally.
sourcepub fn unlocked_fair<F, U>(s: &mut Self, f: F) -> U where
F: FnOnce() -> U,
pub fn unlocked_fair<F, U>(s: &mut Self, f: F) -> U where
F: FnOnce() -> U,
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
.
Trait Implementations
sourceimpl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> Deref for RwLockReadGuard<'a, R, T>
impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> Deref for RwLockReadGuard<'a, R, T>
Auto Trait Implementations
impl<'a, R, T> !RefUnwindSafe for RwLockReadGuard<'a, R, T>
impl<'a, R, T: ?Sized> Send for RwLockReadGuard<'a, R, T> where
R: Sync,
T: Send + Sync,
<R as RawRwLock>::GuardMarker: Send,
impl<'a, R, T: ?Sized> Sync for RwLockReadGuard<'a, R, T> where
R: Sync,
T: Send + Sync,
<R as RawRwLock>::GuardMarker: Sync,
impl<'a, R, T: ?Sized> Unpin for RwLockReadGuard<'a, R, T> where
<R as RawRwLock>::GuardMarker: Unpin,
impl<'a, R, T> !UnwindSafe for RwLockReadGuard<'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