Struct sync_2::Mutex

pub struct Mutex<T> { /* fields omitted */ }

An allocation-free Mutex made in pure Rust.

Implementations

impl<T> Mutex<T>

pub fn new(x: T) -> Self

Creates a new mutex in an unlocked state ready for use.

This function it's constant only without debug_assertions due to declare a thread local storage to avoid acquire the lock twice from the same thread.

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

Acquires a mutex, blocking the current thread until it is able to do so.

This function will block the local thread until it is available to acquire the mutex. Upon returning, the thread is the only thread with the lock held. An RAII guard is returned to allow scoped unlock of the lock. When the guard goes out of scope, the mutex will be unlocked.

The exact behavior on locking a mutex in the thread which already holds the lock is left unspecified. However, this function will not return on the second call (it might panic or deadlock, for example).

Errors

If another user of this mutex panicked while holding the mutex, then this call will return an error once the mutex is acquired.

Panics

This function might panic when called if the lock is already held by the current thread only with debug_assertions.

Examples

use std::sync::Arc;
use sync_2::Mutex;
use std::thread;

let mutex = Arc::new(Mutex::new(0));
let c_mutex = mutex.clone();

thread::spawn(move || {
    *c_mutex.lock().unwrap() = 10;
}).join().expect("thread::spawn failed");
assert_eq!(*mutex.lock().unwrap(), 10);

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

Attempts to acquire this lock.

If the lock could not be acquired at this time, then Err is returned. Otherwise, an RAII guard is returned. The lock will be unlocked when the guard is dropped.

This function does not block.

Errors

If another user of this mutex panicked while holding the mutex, then this call will return failure if the mutex would otherwise be acquired.

Examples

use std::sync::Arc;
use sync_2::Mutex;
use std::thread;

let mutex = Arc::new(Mutex::new(0));
let c_mutex = mutex.clone();

thread::spawn(move || {
    let mut lock = c_mutex.try_lock();
    if let Ok(ref mut mutex) = lock {
        **mutex = 10;
    } else {
        println!("try_lock failed");
    }
}).join().expect("thread::spawn failed");
assert_eq!(*mutex.lock().unwrap(), 10);

pub fn is_poisoned(&self) -> bool

Determines whether the mutex is poisoned.

If another thread is active, the mutex can still become poisoned at any time. You should not trust a false value for program correctness without additional synchronization.

Examples

use std::sync::Arc;
use sync_2::Mutex;
use std::thread;

let mutex = Arc::new(Mutex::new(0));
let c_mutex = mutex.clone();

let _ = thread::spawn(move || {
    let _lock = c_mutex.lock().unwrap();
    panic!(); // the mutex gets poisoned
}).join();
assert_eq!(mutex.is_poisoned(), true);

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

Returns a mutable reference to the underlying data.

Since this call borrows the Mutex mutably, no actual locking needs to take place -- the mutable borrow statically guarantees no locks exist.

Errors

If another user of this mutex panicked while holding the mutex, then this call will return an error instead.

Examples

use sync_2::Mutex;

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

pub fn into_inner(self) -> LockResult<T>

Consumes this mutex, returning the underlying data.

Errors

If another user of this mutex panicked while holding the mutex, then this call will return an error instead.

Examples

use sync_2::Mutex;

let mutex = Mutex::new(0);
assert_eq!(mutex.into_inner().unwrap(), 0);

Trait Implementations

impl<T: Send> Send for Mutex<T>

impl<T: Send> Sync for Mutex<T>