pub struct G_VARS { /* private fields */ }
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).
If another user of this mutex panicked while holding the mutex, then
this call will return an error once the mutex is acquired.
This function might panic when called if the lock is already held by
the current thread.
use std::sync::{Arc, Mutex};
use std::thread;
let mutex = Arc::new(Mutex::new(0));
let c_mutex = Arc::clone(&mutex);
thread::spawn(move || {
*c_mutex.lock().unwrap() = 10;
}).join().expect("thread::spawn failed");
assert_eq!(*mutex.lock().unwrap(), 10);
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.
If another user of this mutex panicked while holding the mutex, then
this call will return the Poisoned
error if the mutex would
otherwise be acquired.
If the mutex could not be acquired because it is already locked, then
this call will return the WouldBlock
error.
use std::sync::{Arc, Mutex};
use std::thread;
let mutex = Arc::new(Mutex::new(0));
let c_mutex = Arc::clone(&mutex);
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);
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.
use std::sync::{Arc, Mutex};
use std::thread;
let mutex = Arc::new(Mutex::new(0));
let c_mutex = Arc::clone(&mutex);
let _ = thread::spawn(move || {
let _lock = c_mutex.lock().unwrap();
panic!(); }).join();
assert_eq!(mutex.is_poisoned(), true);
🔬This is a nightly-only experimental API. (mutex_unpoison
)
Clear the poisoned state from a mutex
If the mutex is poisoned, it will remain poisoned until this function is called. This
allows recovering from a poisoned state and marking that it has recovered. For example, if
the value is overwritten by a known-good value, then the mutex can be marked as
un-poisoned. Or possibly, the value could be inspected to determine if it is in a
consistent state, and if so the poison is removed.
#![feature(mutex_unpoison)]
use std::sync::{Arc, Mutex};
use std::thread;
let mutex = Arc::new(Mutex::new(0));
let c_mutex = Arc::clone(&mutex);
let _ = thread::spawn(move || {
let _lock = c_mutex.lock().unwrap();
panic!(); }).join();
assert_eq!(mutex.is_poisoned(), true);
let x = mutex.lock().unwrap_or_else(|mut e| {
**e.get_mut() = 1;
mutex.clear_poison();
e.into_inner()
});
assert_eq!(mutex.is_poisoned(), false);
assert_eq!(*x, 1);
The resulting type after dereferencing.
Dereferences the value.
Immutably borrows from an owned value.
Read more
Mutably borrows from an owned value.
Read more
Returns the argument unchanged.
Instruments this type with the provided
Span
, returning an
Instrumented
wrapper.
Read more
Instruments this type with the provided
Span
, returning an
Instrumented
wrapper.
Read more
Instruments this type with the
current Span
, returning an
Instrumented
wrapper.
Read more
Calls U::from(self)
.
That is, this conversion is whatever the implementation of
From<T> for U
chooses to do.
The alignment of pointer.
The type for initializers.
Initializes a with the given initializer.
Read more
Mutably dereferences the given pointer.
Read more
Drops the object pointed to by the given pointer.
Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.