Type Alias holochain::prelude::dependencies::kitsune_p2p_types::dependencies::lair_keystore_api::dependencies::parking_lot::MappedReentrantMutexGuard
source · pub type MappedReentrantMutexGuard<'a, T> = MappedReentrantMutexGuard<'a, RawMutex, RawThreadId, T>;
Expand description
An RAII mutex guard returned by ReentrantMutexGuard::map
, which can point to a
subfield of the protected data.
The main difference between MappedReentrantMutexGuard
and ReentrantMutexGuard
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.
Aliased Type§
struct MappedReentrantMutexGuard<'a, T> { /* private fields */ }
Implementations§
§impl<'a, R, G, T> MappedReentrantMutexGuard<'a, R, G, T>where
R: RawMutex + 'a,
G: GetThreadId + 'a,
T: 'a + ?Sized,
impl<'a, R, G, T> MappedReentrantMutexGuard<'a, R, G, T>where R: RawMutex + 'a, G: GetThreadId + 'a, T: 'a + ?Sized,
pub fn map<U, F>(
s: MappedReentrantMutexGuard<'a, R, G, T>,
f: F
) -> MappedReentrantMutexGuard<'a, R, G, U>where
F: FnOnce(&T) -> &U,
U: ?Sized,
pub fn map<U, F>( s: MappedReentrantMutexGuard<'a, R, G, T>, f: F ) -> MappedReentrantMutexGuard<'a, R, G, U>where F: FnOnce(&T) -> &U, U: ?Sized,
Makes a new MappedReentrantMutexGuard
for a component of the locked data.
This operation cannot fail as the MappedReentrantMutexGuard
passed
in already locked the mutex.
This is an associated function that needs to be
used as MappedReentrantMutexGuard::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: MappedReentrantMutexGuard<'a, R, G, T>,
f: F
) -> Result<MappedReentrantMutexGuard<'a, R, G, U>, MappedReentrantMutexGuard<'a, R, G, T>>where
F: FnOnce(&T) -> Option<&U>,
U: ?Sized,
pub fn try_map<U, F>( s: MappedReentrantMutexGuard<'a, R, G, T>, f: F ) -> Result<MappedReentrantMutexGuard<'a, R, G, U>, MappedReentrantMutexGuard<'a, R, G, T>>where F: FnOnce(&T) -> Option<&U>, U: ?Sized,
Attempts to make a new MappedReentrantMutexGuard
for a component of the
locked data. The original guard is return if the closure returns None
.
This operation cannot fail as the MappedReentrantMutexGuard
passed
in already locked the mutex.
This is an associated function that needs to be
used as MappedReentrantMutexGuard::try_map(...)
. A method would interfere with methods of
the same name on the contents of the locked data.
§impl<'a, R, G, T> MappedReentrantMutexGuard<'a, R, G, T>where
R: RawMutexFair + 'a,
G: GetThreadId + 'a,
T: 'a + ?Sized,
impl<'a, R, G, T> MappedReentrantMutexGuard<'a, R, G, T>where R: RawMutexFair + 'a, G: GetThreadId + 'a, T: 'a + ?Sized,
pub fn unlock_fair(s: MappedReentrantMutexGuard<'a, R, G, T>)
pub fn unlock_fair(s: MappedReentrantMutexGuard<'a, R, G, 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 ReentrantMutexGuard
normally.