Struct holochain::prelude::dependencies::kitsune_p2p_types::dependencies::lair_keystore_api::dependencies::parking_lot::lock_api::MappedMutexGuard
pub struct MappedMutexGuard<'a, R, T>where
R: RawMutex,
T: ?Sized,{ /* private fields */ }
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: RawMutex + 'a,
T: 'a + ?Sized,
impl<'a, R, T> MappedMutexGuard<'a, R, T>where R: RawMutex + 'a, 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: RawMutexFair + 'a,
T: 'a + ?Sized,
impl<'a, R, T> MappedMutexGuard<'a, R, T>where R: RawMutexFair + 'a, 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> Deref for MappedMutexGuard<'a, R, T>where
R: RawMutex + 'a,
T: 'a + ?Sized,
impl<'a, R, T> Deref for MappedMutexGuard<'a, R, T>where R: RawMutex + 'a, T: 'a + ?Sized,
§impl<'a, R, T> DerefMut for MappedMutexGuard<'a, R, T>where
R: RawMutex + 'a,
T: 'a + ?Sized,
impl<'a, R, T> DerefMut for MappedMutexGuard<'a, R, T>where R: RawMutex + 'a, T: 'a + ?Sized,
§impl<'a, R, T> Display for MappedMutexGuard<'a, R, T>where
R: RawMutex + 'a,
T: Display + 'a + ?Sized,
impl<'a, R, T> Display for MappedMutexGuard<'a, R, T>where R: RawMutex + 'a, T: Display + 'a + ?Sized,
§impl<'a, R, T> Drop for MappedMutexGuard<'a, R, T>where
R: RawMutex + 'a,
T: 'a + ?Sized,
impl<'a, R, T> Drop for MappedMutexGuard<'a, R, T>where R: RawMutex + 'a, T: 'a + ?Sized,
impl<'a, R, T> Send for MappedMutexGuard<'a, R, T>where R: RawMutex + 'a, T: Send + 'a + ?Sized, <R as RawMutex>::GuardMarker: Send,
impl<'a, R, T> Sync for MappedMutexGuard<'a, R, T>where R: RawMutex + Sync + 'a, T: Sync + 'a + ?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§
§impl<T> ArchivePointee for T
impl<T> ArchivePointee for T
§type ArchivedMetadata = ()
type ArchivedMetadata = ()
§fn pointer_metadata(
_: &<T as ArchivePointee>::ArchivedMetadata
) -> <T as Pointee>::Metadata
fn pointer_metadata( _: &<T as ArchivePointee>::ArchivedMetadata ) -> <T as Pointee>::Metadata
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
§impl<F, W, T, D> Deserialize<With<T, W>, D> for Fwhere
W: DeserializeWith<F, T, D>,
D: Fallible + ?Sized,
F: ?Sized,
impl<F, W, T, D> Deserialize<With<T, W>, D> for Fwhere W: DeserializeWith<F, T, D>, D: Fallible + ?Sized, F: ?Sized,
§fn deserialize(
&self,
deserializer: &mut D
) -> Result<With<T, W>, <D as Fallible>::Error>
fn deserialize( &self, deserializer: &mut D ) -> Result<With<T, W>, <D as Fallible>::Error>
source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
source§fn in_current_span(self) -> Instrumented<Self> ⓘ
fn in_current_span(self) -> Instrumented<Self> ⓘ
source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
source§fn in_current_span(self) -> Instrumented<Self> ⓘ
fn in_current_span(self) -> Instrumented<Self> ⓘ
§impl<T> Pointable for T
impl<T> Pointable for T
§impl<SS, SP> SupersetOf<SS> for SPwhere
SS: SubsetOf<SP>,
impl<SS, SP> SupersetOf<SS> for SPwhere SS: SubsetOf<SP>,
§fn to_subset(&self) -> Option<SS>
fn to_subset(&self) -> Option<SS>
self
from the equivalent element of its
superset. Read more§fn is_in_subset(&self) -> bool
fn is_in_subset(&self) -> bool
self
is actually part of its subset T
(and can be converted to it).§fn to_subset_unchecked(&self) -> SS
fn to_subset_unchecked(&self) -> SS
self.to_subset
but without any property checks. Always succeeds.§fn from_subset(element: &SS) -> SP
fn from_subset(element: &SS) -> SP
self
to the equivalent element of its superset.