pub struct Mutex<T: ?Sized> { /* private fields */ }
Expand description
This type provides MUTual EXclusion based on spinning.
Description
The behaviour of these lock is similar to their namesakes in std::sync
. they
differ on the following:
- The lock will not be poisoned in case of failure;
Simple examples
use spin;
let spin_mutex = spin::Mutex::new(0);
// Modify the data
{
let mut data = spin_mutex.lock();
*data = 2;
}
// Read the data
let answer =
{
let data = spin_mutex.lock();
*data
};
assert_eq!(answer, 2);
Thread-safety example
use spin;
use std::sync::{Arc, Barrier};
let numthreads = 1000;
let spin_mutex = Arc::new(spin::Mutex::new(0));
// We use a barrier to ensure the readout happens after all writing
let barrier = Arc::new(Barrier::new(numthreads + 1));
for _ in (0..numthreads)
{
let my_barrier = barrier.clone();
let my_lock = spin_mutex.clone();
std::thread::spawn(move||
{
let mut guard = my_lock.lock();
*guard += 1;
// Release the lock to prevent a deadlock
drop(guard);
my_barrier.wait();
});
}
barrier.wait();
let answer = { *spin_mutex.lock() };
assert_eq!(answer, numthreads);
Implementations
sourceimpl<T> Mutex<T>
impl<T> Mutex<T>
sourcepub const fn new(user_data: T) -> Mutex<T>
pub const fn new(user_data: T) -> Mutex<T>
Creates a new spinlock wrapping the supplied data.
May be used statically:
use spin;
static MUTEX: spin::Mutex<()> = spin::Mutex::new(());
fn demo() {
let lock = MUTEX.lock();
// do something with lock
drop(lock);
}
sourcepub fn into_inner(self) -> T
pub fn into_inner(self) -> T
Consumes this mutex, returning the underlying data.
sourceimpl<T: ?Sized> Mutex<T>
impl<T: ?Sized> Mutex<T>
sourcepub fn lock(&self) -> MutexGuard<'_, T>
pub fn lock(&self) -> MutexGuard<'_, T>
Locks the spinlock and returns a guard.
The returned value may be dereferenced for data access and the lock will be dropped when the guard falls out of scope.
let mylock = spin::Mutex::new(0);
{
let mut data = mylock.lock();
// The lock is now locked and the data can be accessed
*data += 1;
// The lock is implicitly dropped
}
sourcepub unsafe fn force_unlock(&self)
pub unsafe fn force_unlock(&self)
Force unlock the spinlock.
This is extremely unsafe if the lock is not held by the current thread. However, this can be useful in some instances for exposing the lock to FFI that doesn’t know how to deal with RAII.
If the lock isn’t held, this is a no-op.
sourcepub fn try_lock(&self) -> Option<MutexGuard<'_, T>>
pub fn try_lock(&self) -> Option<MutexGuard<'_, T>>
Tries to lock the mutex. If it is already locked, it will return None. Otherwise it returns a guard within Some.