Struct async_lock::RwLockUpgradableReadGuardArc

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pub struct RwLockUpgradableReadGuardArc<T: ?Sized> { /* private fields */ }
Expand description

An owned, reference-counting guard that releases the upgradable read lock when dropped.

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impl<T> RwLockUpgradableReadGuardArc<T>

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pub fn downgrade(guard: Self) -> RwLockReadGuardArc<T>

Downgrades into a regular reader guard.

§Examples
use std::sync::Arc;
use async_lock::{RwLock, RwLockUpgradableReadGuardArc};

let lock = Arc::new(RwLock::new(1));

let reader = lock.upgradable_read_arc().await;
assert_eq!(*reader, 1);

assert!(lock.try_upgradable_read_arc().is_none());

let reader = RwLockUpgradableReadGuardArc::downgrade(reader);

assert!(lock.try_upgradable_read_arc().is_some());
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impl<T: ?Sized> RwLockUpgradableReadGuardArc<T>

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pub fn try_upgrade(guard: Self) -> Result<RwLockWriteGuardArc<T>, Self>

Attempts to upgrade into a write lock.

If a write lock could not be acquired at this time, then None is returned. Otherwise, an upgraded guard is returned that releases the write lock when dropped.

This function can only fail if there are other active read locks.

§Examples
use std::sync::Arc;
use async_lock::{RwLock, RwLockUpgradableReadGuardArc};

let lock = Arc::new(RwLock::new(1));

let reader = lock.upgradable_read_arc().await;
assert_eq!(*reader, 1);

let reader2 = lock.read_arc().await;
let reader = RwLockUpgradableReadGuardArc::try_upgrade(reader).unwrap_err();

drop(reader2);
let writer = RwLockUpgradableReadGuardArc::try_upgrade(reader).unwrap();
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pub fn upgrade(guard: Self) -> UpgradeArc<T>

Upgrades into a write lock.

§Examples
use std::sync::Arc;
use async_lock::{RwLock, RwLockUpgradableReadGuardArc};

let lock = Arc::new(RwLock::new(1));

let reader = lock.upgradable_read_arc().await;
assert_eq!(*reader, 1);

let mut writer = RwLockUpgradableReadGuardArc::upgrade(reader).await;
*writer = 2;
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pub fn upgrade_blocking(guard: Self) -> RwLockWriteGuardArc<T>

Upgrades into a write lock.

§Blocking

This function will block the current thread until it is able to acquire the write lock.

§Examples
use std::sync::Arc;
use async_lock::{RwLock, RwLockUpgradableReadGuardArc};

let lock = Arc::new(RwLock::new(1));

let reader = lock.upgradable_read_arc_blocking();
assert_eq!(*reader, 1);

let mut writer = RwLockUpgradableReadGuardArc::upgrade_blocking(reader);
*writer = 2;

Trait Implementations§

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impl<T: Debug + ?Sized> Debug for RwLockUpgradableReadGuardArc<T>

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl<T: ?Sized> Deref for RwLockUpgradableReadGuardArc<T>

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type Target = T

The resulting type after dereferencing.
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fn deref(&self) -> &T

Dereferences the value.
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impl<T: Display + ?Sized> Display for RwLockUpgradableReadGuardArc<T>

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl<T: ?Sized> Drop for RwLockUpgradableReadGuardArc<T>

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fn drop(&mut self)

Executes the destructor for this type. Read more
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impl<T: Send + Sync + ?Sized> Send for RwLockUpgradableReadGuardArc<T>

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impl<T: Send + Sync + ?Sized> Sync for RwLockUpgradableReadGuardArc<T>

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToString for T
where T: Display + ?Sized,

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default fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.