Struct holochain::prelude::dependencies::kitsune_p2p_types::dependencies::lair_keystore_api::dependencies::parking_lot::lock_api::MappedRwLockReadGuard
Expand description
An RAII read lock guard returned by RwLockReadGuard::map
, which can point to a
subfield of the protected data.
The main difference between MappedRwLockReadGuard
and RwLockReadGuard
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> MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + ?Sized,
impl<'a, R, T> MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + ?Sized,
pub fn map<U, F>(
s: MappedRwLockReadGuard<'a, R, T>,
f: F
) -> MappedRwLockReadGuard<'a, R, U>where
F: FnOnce(&T) -> &U,
U: ?Sized,
pub fn map<U, F>(
s: MappedRwLockReadGuard<'a, R, T>,
f: F
) -> MappedRwLockReadGuard<'a, R, U>where
F: FnOnce(&T) -> &U,
U: ?Sized,
Make a new MappedRwLockReadGuard
for a component of the locked data.
This operation cannot fail as the MappedRwLockReadGuard
passed
in already locked the data.
This is an associated function that needs to be
used as MappedRwLockReadGuard::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: MappedRwLockReadGuard<'a, R, T>,
f: F
) -> Result<MappedRwLockReadGuard<'a, R, U>, MappedRwLockReadGuard<'a, R, T>>where
F: FnOnce(&T) -> Option<&U>,
U: ?Sized,
pub fn try_map<U, F>(
s: MappedRwLockReadGuard<'a, R, T>,
f: F
) -> Result<MappedRwLockReadGuard<'a, R, U>, MappedRwLockReadGuard<'a, R, T>>where
F: FnOnce(&T) -> Option<&U>,
U: ?Sized,
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 MappedRwLockReadGuard
passed
in already locked the data.
This is an associated function that needs to be
used as MappedRwLockReadGuard::try_map(...)
. A method would interfere with methods of
the same name on the contents of the locked data.
impl<'a, R, T> MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLockFair,
T: 'a + ?Sized,
impl<'a, R, T> MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLockFair,
T: 'a + ?Sized,
pub fn unlock_fair(s: MappedRwLockReadGuard<'a, R, T>)
pub fn unlock_fair(s: MappedRwLockReadGuard<'a, R, T>)
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 MappedRwLockReadGuard
normally.
Trait Implementations
impl<'a, R, T> Debug for MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + Debug + ?Sized,
impl<'a, R, T> Debug for MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + Debug + ?Sized,
impl<'a, R, T> Deref for MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + ?Sized,
impl<'a, R, T> Deref for MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + ?Sized,
impl<'a, R, T> Display for MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + Display + ?Sized,
impl<'a, R, T> Display for MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + Display + ?Sized,
impl<'a, R, T> Drop for MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + ?Sized,
impl<'a, R, T> Drop for MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + ?Sized,
impl<'a, R, T> Send for MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + Sync + ?Sized,
<R as RawRwLock>::GuardMarker: Send,
impl<'a, R, T> Sync for MappedRwLockReadGuard<'a, R, T>where
R: 'a + RawRwLock,
T: 'a + Sync + ?Sized,
Auto Trait Implementations
impl<'a, R, T: ?Sized> RefUnwindSafe for MappedRwLockReadGuard<'a, R, T>where
R: RefUnwindSafe,
T: RefUnwindSafe,
impl<'a, R, T: ?Sized> Unpin for MappedRwLockReadGuard<'a, R, T>
impl<'a, R, T: ?Sized> UnwindSafe for MappedRwLockReadGuard<'a, R, T>where
R: RefUnwindSafe,
T: RefUnwindSafe,
Blanket Implementations
impl<T> Any for Twhere
T: Any + ?Sized,
impl<T> Any for Twhere
T: Any + ?Sized,
fn type_id_compat(&self) -> TypeId
fn type_id_compat(&self) -> TypeId
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
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn 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>
impl<T> FutureExt for T
impl<T> FutureExt for T
fn with_context(self, otel_cx: Context) -> WithContext<Self> ⓘ
fn with_context(self, otel_cx: Context) -> WithContext<Self> ⓘ
fn with_current_context(self) -> WithContext<Self> ⓘ
fn with_current_context(self) -> WithContext<Self> ⓘ
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
sourcefn in_current_span(self) -> Instrumented<Self> ⓘ
fn in_current_span(self) -> Instrumented<Self> ⓘ
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
sourcefn 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 morefn 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.