Struct async_lock::RwLockUpgradableReadGuardArc

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

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

Implementations

impl<T> RwLockUpgradableReadGuardArc<T>

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());

impl<T: ?Sized> RwLockUpgradableReadGuardArc<T>

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();

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;

Trait Implementations

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

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

Formats the value using the given formatter.

impl<T: ?Sized> Deref for RwLockUpgradableReadGuardArc<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

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

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

Formats the value using the given formatter.

impl<T: ?Sized> Drop for RwLockUpgradableReadGuardArc<T>

fn drop(&mut self)

Executes the destructor for this type.

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

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