Struct async_lock::RwLockUpgradableReadGuard[][src]

pub struct RwLockUpgradableReadGuard<'a, T: ?Sized> { /* fields omitted */ }

A guard that releases the upgradable read lock when dropped.

Implementations

impl<'a, T: ?Sized> RwLockUpgradableReadGuard<'a, T>[src]

pub fn downgrade(guard: Self) -> RwLockReadGuard<'a, T>[src]

Downgrades into a regular reader guard.

Examples

use async_lock::{RwLock, RwLockUpgradableReadGuard};

let lock = RwLock::new(1);

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

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

let reader = RwLockUpgradableReadGuard::downgrade(reader);

assert!(lock.try_upgradable_read().is_some());

pub fn try_upgrade(guard: Self) -> Result<RwLockWriteGuard<'a, T>, Self>[src]

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 async_lock::{RwLock, RwLockUpgradableReadGuard};

let lock = RwLock::new(1);

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

let reader2 = lock.read().await;
let reader = RwLockUpgradableReadGuard::try_upgrade(reader).unwrap_err();

drop(reader2);
let writer = RwLockUpgradableReadGuard::try_upgrade(reader).unwrap();

pub async fn upgrade(guard: Self) -> RwLockWriteGuard<'a, T>[src]

Upgrades into a write lock.

Examples

use async_lock::{RwLock, RwLockUpgradableReadGuard};

let lock = RwLock::new(1);

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

let mut writer = RwLockUpgradableReadGuard::upgrade(reader).await;
*writer = 2;

Trait Implementations

impl<T: Debug + ?Sized> Debug for RwLockUpgradableReadGuard<'_, T>[src]

impl<T: ?Sized> Deref for RwLockUpgradableReadGuard<'_, T>[src]

type Target = T

The resulting type after dereferencing.

impl<T: Display + ?Sized> Display for RwLockUpgradableReadGuard<'_, T>[src]

impl<T: Send + Sync + ?Sized> Send for RwLockUpgradableReadGuard<'_, T>[src]

impl<T: Sync + ?Sized> Sync for RwLockUpgradableReadGuard<'_, T>[src]

Auto Trait Implementations

impl<'a, T> !RefUnwindSafe for RwLockUpgradableReadGuard<'a, T>

impl<'a, T: ?Sized> Unpin for RwLockUpgradableReadGuard<'a, T>

impl<'a, T> !UnwindSafe for RwLockUpgradableReadGuard<'a, T>

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
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impl<T> Borrow<T> for T where
    T: ?Sized
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impl<T> BorrowMut<T> for T where
    T: ?Sized
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impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> ToString for T where
    T: Display + ?Sized
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impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

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

The type returned in the event of a conversion error.