Module std::sync::atomic 1.0.0
[−]
[src]
Atomic types
Atomic types provide primitive shared-memory communication between threads, and are the building blocks of other concurrent types.
This module defines atomic versions of a select number of primitive
types, including AtomicBool
, AtomicIsize
, and AtomicUsize
.
Atomic types present operations that, when used correctly, synchronize
updates between threads.
Each method takes an Ordering
which represents the strength of
the memory barrier for that operation. These orderings are the
same as LLVM atomic orderings. For more information see the nomicon.
Atomic variables are safe to share between threads (they implement Sync
)
but they do not themselves provide the mechanism for sharing and follow the
threading model of rust.
The most common way to share an atomic variable is to put it into an Arc
(an
atomically-reference-counted shared pointer).
Most atomic types may be stored in static variables, initialized using
the provided static initializers like ATOMIC_BOOL_INIT
. Atomic statics
are often used for lazy global initialization.
Examples
A simple spinlock:
use std::sync::Arc; use std::sync::atomic::{AtomicUsize, Ordering}; use std::thread; fn main() { let spinlock = Arc::new(AtomicUsize::new(1)); let spinlock_clone = spinlock.clone(); let thread = thread::spawn(move|| { spinlock_clone.store(0, Ordering::SeqCst); }); // Wait for the other thread to release the lock while spinlock.load(Ordering::SeqCst) != 0 {} if let Err(panic) = thread.join() { println!("Thread had an error: {:?}", panic); } }Run
Keep a global count of live threads:
use std::sync::atomic::{AtomicUsize, Ordering, ATOMIC_USIZE_INIT}; static GLOBAL_THREAD_COUNT: AtomicUsize = ATOMIC_USIZE_INIT; let old_thread_count = GLOBAL_THREAD_COUNT.fetch_add(1, Ordering::SeqCst); println!("live threads: {}", old_thread_count + 1);Run
Structs
AtomicBool |
A boolean type which can be safely shared between threads. |
AtomicIsize |
An integer type which can be safely shared between threads. |
AtomicPtr |
A raw pointer type which can be safely shared between threads. |
AtomicUsize |
An integer type which can be safely shared between threads. |
AtomicI8 |
[ Experimental ] An integer type which can be safely shared between threads. |
AtomicI16 |
[ Experimental ] An integer type which can be safely shared between threads. |
AtomicI32 |
[ Experimental ] An integer type which can be safely shared between threads. |
AtomicI64 |
[ Experimental ] An integer type which can be safely shared between threads. |
AtomicU8 |
[ Experimental ] An integer type which can be safely shared between threads. |
AtomicU16 |
[ Experimental ] An integer type which can be safely shared between threads. |
AtomicU32 |
[ Experimental ] An integer type which can be safely shared between threads. |
AtomicU64 |
[ Experimental ] An integer type which can be safely shared between threads. |
Enums
Ordering |
Atomic memory orderings |
Constants
ATOMIC_BOOL_INIT |
An |
ATOMIC_ISIZE_INIT |
An atomic integer initialized to |
ATOMIC_USIZE_INIT |
An atomic integer initialized to |
ATOMIC_I16_INIT |
[ Experimental ] An atomic integer initialized to |
ATOMIC_I32_INIT |
[ Experimental ] An atomic integer initialized to |
ATOMIC_I64_INIT |
[ Experimental ] An atomic integer initialized to |
ATOMIC_I8_INIT |
[ Experimental ] An atomic integer initialized to |
ATOMIC_U16_INIT |
[ Experimental ] An atomic integer initialized to |
ATOMIC_U32_INIT |
[ Experimental ] An atomic integer initialized to |
ATOMIC_U64_INIT |
[ Experimental ] An atomic integer initialized to |
ATOMIC_U8_INIT |
[ Experimental ] An atomic integer initialized to |
Functions
compiler_fence |
A compiler memory fence. |
fence |
An atomic fence. |
spin_loop_hint |
Save power or switch hyperthreads in a busy-wait spin-loop. |