Struct core::sync::atomic::AtomicUsize
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[src]
pub struct AtomicUsize { // some fields omitted }1.0.0
An unsigned integer type which can be safely shared between threads.
Methods
impl AtomicUsize
const fn new(v: usize) -> AtomicUsize
Creates a new AtomicUsize
.
Examples
fn main() { use std::sync::atomic::AtomicUsize; let atomic_forty_two = AtomicUsize::new(42); }use std::sync::atomic::AtomicUsize; let atomic_forty_two = AtomicUsize::new(42);
fn load(&self, order: Ordering) -> usize
Loads a value from the usize.
load
takes an Ordering
argument which describes the memory ordering of this operation.
Panics
Panics if order
is Release
or AcqRel
.
Examples
fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let some_usize = AtomicUsize::new(5); assert_eq!(some_usize.load(Ordering::Relaxed), 5); }use std::sync::atomic::{AtomicUsize, Ordering}; let some_usize = AtomicUsize::new(5); assert_eq!(some_usize.load(Ordering::Relaxed), 5);
fn store(&self, val: usize, order: Ordering)
Stores a value into the usize.
store
takes an Ordering
argument which describes the memory ordering of this operation.
Examples
fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let some_usize = AtomicUsize::new(5); some_usize.store(10, Ordering::Relaxed); assert_eq!(some_usize.load(Ordering::Relaxed), 10); }use std::sync::atomic::{AtomicUsize, Ordering}; let some_usize = AtomicUsize::new(5); some_usize.store(10, Ordering::Relaxed); assert_eq!(some_usize.load(Ordering::Relaxed), 10);
Panics
Panics if order
is Acquire
or AcqRel
.
fn swap(&self, val: usize, order: Ordering) -> usize
Stores a value into the usize, returning the old value.
swap
takes an Ordering
argument which describes the memory ordering of this operation.
Examples
fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let some_usize = AtomicUsize::new(5); assert_eq!(some_usize.swap(10, Ordering::Relaxed), 5); assert_eq!(some_usize.load(Ordering::Relaxed), 10); }use std::sync::atomic::{AtomicUsize, Ordering}; let some_usize = AtomicUsize::new(5); assert_eq!(some_usize.swap(10, Ordering::Relaxed), 5); assert_eq!(some_usize.load(Ordering::Relaxed), 10);
fn compare_and_swap(&self, current: usize, new: usize, order: Ordering) -> usize
Stores a value into the usize
if the current value is the same as the current
value.
The return value is always the previous value. If it is equal to current
, then the value
was updated.
compare_and_swap
also takes an Ordering
argument which describes the memory ordering of
this operation.
Examples
fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let some_usize = AtomicUsize::new(5); assert_eq!(some_usize.compare_and_swap(5, 10, Ordering::Relaxed), 5); assert_eq!(some_usize.load(Ordering::Relaxed), 10); assert_eq!(some_usize.compare_and_swap(6, 12, Ordering::Relaxed), 10); assert_eq!(some_usize.load(Ordering::Relaxed), 10); }use std::sync::atomic::{AtomicUsize, Ordering}; let some_usize = AtomicUsize::new(5); assert_eq!(some_usize.compare_and_swap(5, 10, Ordering::Relaxed), 5); assert_eq!(some_usize.load(Ordering::Relaxed), 10); assert_eq!(some_usize.compare_and_swap(6, 12, Ordering::Relaxed), 10); assert_eq!(some_usize.load(Ordering::Relaxed), 10);
fn compare_exchange(&self, current: usize, new: usize, success: Ordering, failure: Ordering) -> Result<usize, usize>
Stores a value into the usize
if the current value is the same as the current
value.
The return value is a result indicating whether the new value was written and containing
the previous value. On success this value is guaranteed to be equal to new
.
compare_exchange
takes two Ordering
arguments to describe the memory ordering of this
operation. The first describes the required ordering if the operation succeeds while the
second describes the required ordering when the operation fails. The failure ordering can't
be Release
or AcqRel
and must be equivalent or weaker than the success ordering.
Examples
#![feature(extended_compare_and_swap)] fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let some_isize = AtomicUsize::new(5); assert_eq!(some_isize.compare_exchange(5, 10, Ordering::Acquire, Ordering::Relaxed), Ok(5)); assert_eq!(some_isize.load(Ordering::Relaxed), 10); assert_eq!(some_isize.compare_exchange(6, 12, Ordering::SeqCst, Ordering::Acquire), Err(10)); assert_eq!(some_isize.load(Ordering::Relaxed), 10); }use std::sync::atomic::{AtomicUsize, Ordering}; let some_isize = AtomicUsize::new(5); assert_eq!(some_isize.compare_exchange(5, 10, Ordering::Acquire, Ordering::Relaxed), Ok(5)); assert_eq!(some_isize.load(Ordering::Relaxed), 10); assert_eq!(some_isize.compare_exchange(6, 12, Ordering::SeqCst, Ordering::Acquire), Err(10)); assert_eq!(some_isize.load(Ordering::Relaxed), 10);
fn compare_exchange_weak(&self, current: usize, new: usize, success: Ordering, failure: Ordering) -> Result<usize, usize>
Stores a value into the usize
if the current value is the same as the current
value.
Unlike compare_exchange
, this function is allowed to spuriously fail even when the
comparison succeeds, which can result in more efficient code on some platforms. The
return value is a result indicating whether the new value was written and containing the
previous value.
compare_exchange_weak
takes two Ordering
arguments to describe the memory
ordering of this operation. The first describes the required ordering if the operation
succeeds while the second describes the required ordering when the operation fails. The
failure ordering can't be Release
or AcqRel
and must be equivalent or weaker than the
success ordering.
Examples
#![feature(extended_compare_and_swap)] fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let val = AtomicUsize::new(4); let mut old = val.load(Ordering::Relaxed); loop { let new = old * 2; match val.compare_exchange_weak(old, new, Ordering::SeqCst, Ordering::Relaxed) { Ok(_) => break, Err(x) => old = x, } } }use std::sync::atomic::{AtomicUsize, Ordering}; let val = AtomicUsize::new(4); let mut old = val.load(Ordering::Relaxed); loop { let new = old * 2; match val.compare_exchange_weak(old, new, Ordering::SeqCst, Ordering::Relaxed) { Ok(_) => break, Err(x) => old = x, } }
fn fetch_add(&self, val: usize, order: Ordering) -> usize
Add to the current usize, returning the previous value.
Examples
fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let foo = AtomicUsize::new(0); assert_eq!(foo.fetch_add(10, Ordering::SeqCst), 0); assert_eq!(foo.load(Ordering::SeqCst), 10); }use std::sync::atomic::{AtomicUsize, Ordering}; let foo = AtomicUsize::new(0); assert_eq!(foo.fetch_add(10, Ordering::SeqCst), 0); assert_eq!(foo.load(Ordering::SeqCst), 10);
fn fetch_sub(&self, val: usize, order: Ordering) -> usize
Subtract from the current usize, returning the previous value.
Examples
fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let foo = AtomicUsize::new(10); assert_eq!(foo.fetch_sub(10, Ordering::SeqCst), 10); assert_eq!(foo.load(Ordering::SeqCst), 0); }use std::sync::atomic::{AtomicUsize, Ordering}; let foo = AtomicUsize::new(10); assert_eq!(foo.fetch_sub(10, Ordering::SeqCst), 10); assert_eq!(foo.load(Ordering::SeqCst), 0);
fn fetch_and(&self, val: usize, order: Ordering) -> usize
Bitwise and with the current usize, returning the previous value.
Examples
fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let foo = AtomicUsize::new(0b101101); assert_eq!(foo.fetch_and(0b110011, Ordering::SeqCst), 0b101101); assert_eq!(foo.load(Ordering::SeqCst), 0b100001); }use std::sync::atomic::{AtomicUsize, Ordering}; let foo = AtomicUsize::new(0b101101); assert_eq!(foo.fetch_and(0b110011, Ordering::SeqCst), 0b101101); assert_eq!(foo.load(Ordering::SeqCst), 0b100001);
fn fetch_or(&self, val: usize, order: Ordering) -> usize
Bitwise or with the current usize, returning the previous value.
Examples
fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let foo = AtomicUsize::new(0b101101); assert_eq!(foo.fetch_or(0b110011, Ordering::SeqCst), 0b101101); assert_eq!(foo.load(Ordering::SeqCst), 0b111111); }use std::sync::atomic::{AtomicUsize, Ordering}; let foo = AtomicUsize::new(0b101101); assert_eq!(foo.fetch_or(0b110011, Ordering::SeqCst), 0b101101); assert_eq!(foo.load(Ordering::SeqCst), 0b111111);
fn fetch_xor(&self, val: usize, order: Ordering) -> usize
Bitwise xor with the current usize, returning the previous value.
Examples
fn main() { use std::sync::atomic::{AtomicUsize, Ordering}; let foo = AtomicUsize::new(0b101101); assert_eq!(foo.fetch_xor(0b110011, Ordering::SeqCst), 0b101101); assert_eq!(foo.load(Ordering::SeqCst), 0b011110); }use std::sync::atomic::{AtomicUsize, Ordering}; let foo = AtomicUsize::new(0b101101); assert_eq!(foo.fetch_xor(0b110011, Ordering::SeqCst), 0b101101); assert_eq!(foo.load(Ordering::SeqCst), 0b011110);