Struct Mutex

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

A mutual exclusion primitive for protecting shared data.

This type is an async version of std::sync::Mutex.

Examples

use async_std::sync::{Arc, Mutex};
use async_std::task;

let m = Arc::new(Mutex::new(0));
let mut tasks = vec![];

for _ in 0..10 {
    let m = m.clone();
    tasks.push(task::spawn(async move {
        *m.lock().await += 1;
    }));
}

for t in tasks {
    t.await.unwrap();
}
assert_eq!(*m.lock().await, 10);

Implementations

impl<T> Mutex<T>

pub fn new(t: T) -> Mutex<T>

Creates a new mutex.

Examples

use async_std::sync::Mutex;

let mutex = Mutex::new(0);

impl<T: ?Sized> Mutex<T>

pub async fn lock(&self) -> MutexGuard<'_, T>

Acquires the lock.

Returns a guard that releases the lock when dropped.

Examples

use async_std::sync::{Arc, Mutex};
use async_std::task;

let m1 = Arc::new(Mutex::new(10));
let m2 = m1.clone();

task::spawn(async move {
    *m1.lock().await = 20;
})
.await.unwrap();

assert_eq!(*m2.lock().await, 20);

pub fn try_lock(&self) -> Option<MutexGuard<'_, T>>

Attempts to acquire the lock.

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

Examples

use async_std::sync::{Arc, Mutex};
use async_std::task;

let m1 = Arc::new(Mutex::new(10));
let m2 = m1.clone();

task::spawn(async move {
    if let Some(mut guard) = m1.try_lock() {
        *guard = 20;
    } else {
        println!("try_lock failed");
    }
})
.await.unwrap();

assert_eq!(*m2.lock().await, 20);

pub fn into_inner(self) -> T

where T: Sized,

Consumes the mutex, returning the underlying data.

Examples

use async_std::sync::Mutex;

let mutex = Mutex::new(10);
assert_eq!(mutex.into_inner(), 10);

pub fn get_mut(&mut self) -> &mut T

Returns a mutable reference to the underlying data.

Since this call borrows the mutex mutably, no actual locking takes place – the mutable borrow statically guarantees no locks exist.

Examples

use async_std::sync::Mutex;

let mut mutex = Mutex::new(0);
*mutex.get_mut() = 10;
assert_eq!(*mutex.lock().await, 10);

Trait Implementations

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

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

Formats the value using the given formatter.

impl<T: ?Sized + Default> Default for Mutex<T>

fn default() -> Mutex<T>

Returns the “default value” for a type.

impl<T> From<T> for Mutex<T>

fn from(val: T) -> Mutex<T>

Converts to this type from the input type.

impl<T: ?Sized + Send> Send for Mutex<T>

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