Struct lair_keystore::dependencies::tokio::sync::OwnedMutexGuard
source · pub struct OwnedMutexGuard<T>where
T: ?Sized,{ /* private fields */ }
Expand description
An owned handle to a held Mutex
.
This guard is only available from a Mutex
that is wrapped in an Arc
. It
is identical to MutexGuard
, except that rather than borrowing the Mutex
,
it clones the Arc
, incrementing the reference count. This means that
unlike MutexGuard
, it will have the 'static
lifetime.
As long as you have this guard, you have exclusive access to the underlying
T
. The guard internally keeps a reference-counted pointer to the original
Mutex
, so even if the lock goes away, the guard remains valid.
The lock is automatically released whenever the guard is dropped, at which
point lock
will succeed yet again.
Implementations§
source§impl<T> OwnedMutexGuard<T>where
T: ?Sized,
impl<T> OwnedMutexGuard<T>where
T: ?Sized,
sourcepub fn map<U, F>(this: OwnedMutexGuard<T>, f: F) -> OwnedMappedMutexGuard<T, U>
pub fn map<U, F>(this: OwnedMutexGuard<T>, f: F) -> OwnedMappedMutexGuard<T, U>
Makes a new OwnedMappedMutexGuard
for a component of the locked data.
This operation cannot fail as the OwnedMutexGuard
passed in already locked the mutex.
This is an associated function that needs to be used as OwnedMutexGuard::map(...)
. A method
would interfere with methods of the same name on the contents of the locked data.
§Examples
use tokio::sync::{Mutex, OwnedMutexGuard};
use std::sync::Arc;
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);
let foo = Arc::new(Mutex::new(Foo(1)));
{
let mut mapped = OwnedMutexGuard::map(foo.clone().lock_owned().await, |f| &mut f.0);
*mapped = 2;
}
assert_eq!(Foo(2), *foo.lock().await);
sourcepub fn try_map<U, F>(
this: OwnedMutexGuard<T>,
f: F,
) -> Result<OwnedMappedMutexGuard<T, U>, OwnedMutexGuard<T>>
pub fn try_map<U, F>( this: OwnedMutexGuard<T>, f: F, ) -> Result<OwnedMappedMutexGuard<T, U>, OwnedMutexGuard<T>>
Attempts to make a new OwnedMappedMutexGuard
for a component of the locked data. The
original guard is returned if the closure returns None
.
This operation cannot fail as the OwnedMutexGuard
passed in already locked the mutex.
This is an associated function that needs to be used as OwnedMutexGuard::try_map(...)
. A
method would interfere with methods of the same name on the contents of the locked data.
§Examples
use tokio::sync::{Mutex, OwnedMutexGuard};
use std::sync::Arc;
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
struct Foo(u32);
let foo = Arc::new(Mutex::new(Foo(1)));
{
let mut mapped = OwnedMutexGuard::try_map(foo.clone().lock_owned().await, |f| Some(&mut f.0))
.expect("should not fail");
*mapped = 2;
}
assert_eq!(Foo(2), *foo.lock().await);
sourcepub fn mutex(this: &OwnedMutexGuard<T>) -> &Arc<Mutex<T>>
pub fn mutex(this: &OwnedMutexGuard<T>) -> &Arc<Mutex<T>>
Returns a reference to the original Arc<Mutex>
.
use std::sync::Arc;
use tokio::sync::{Mutex, OwnedMutexGuard};
async fn unlock_and_relock(guard: OwnedMutexGuard<u32>) -> OwnedMutexGuard<u32> {
println!("1. contains: {:?}", *guard);
let mutex: Arc<Mutex<u32>> = OwnedMutexGuard::mutex(&guard).clone();
drop(guard);
let guard = mutex.lock_owned().await;
println!("2. contains: {:?}", *guard);
guard
}
Trait Implementations§
source§impl<T> Debug for OwnedMutexGuard<T>
impl<T> Debug for OwnedMutexGuard<T>
source§impl<T> Deref for OwnedMutexGuard<T>where
T: ?Sized,
impl<T> Deref for OwnedMutexGuard<T>where
T: ?Sized,
source§impl<T> DerefMut for OwnedMutexGuard<T>where
T: ?Sized,
impl<T> DerefMut for OwnedMutexGuard<T>where
T: ?Sized,
source§impl<T> Display for OwnedMutexGuard<T>
impl<T> Display for OwnedMutexGuard<T>
source§impl<T> Drop for OwnedMutexGuard<T>where
T: ?Sized,
impl<T> Drop for OwnedMutexGuard<T>where
T: ?Sized,
impl<T> Sync for OwnedMutexGuard<T>
Auto Trait Implementations§
impl<T> Freeze for OwnedMutexGuard<T>where
T: ?Sized,
impl<T> !RefUnwindSafe for OwnedMutexGuard<T>
impl<T> Send for OwnedMutexGuard<T>
impl<T> Unpin for OwnedMutexGuard<T>where
T: ?Sized,
impl<T> !UnwindSafe for OwnedMutexGuard<T>
Blanket Implementations§
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
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> IntoEither for T
impl<T> IntoEither for T
source§fn into_either(self, into_left: bool) -> Either<Self, Self> ⓘ
fn into_either(self, into_left: bool) -> Either<Self, Self> ⓘ
self
into a Left
variant of Either<Self, Self>
if into_left
is true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read moresource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self> ⓘ
self
into a Left
variant of Either<Self, Self>
if into_left(&self)
returns true
.
Converts self
into a Right
variant of Either<Self, Self>
otherwise. Read more