Struct std::sync::atomic::AtomicPtr

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

A raw pointer type which can be safely shared between threads.

This type has the same in-memory representation as a *mut T.

Methods

impl<T> AtomicPtr<T>

const fn new(p: *mut T) -> AtomicPtr<T>

Creates a new AtomicPtr.

Examples

use std::sync::atomic::AtomicPtr;

let ptr = &mut 5;
let atomic_ptr  = AtomicPtr::new(ptr);

fn get_mut(&mut self) -> &mut *mut T

Returns a mutable reference to the underlying pointer.

This is safe because the mutable reference guarantees that no other threads are concurrently accessing the atomic data.

Examples

use std::sync::atomic::{AtomicPtr, Ordering};

let mut atomic_ptr = AtomicPtr::new(&mut 10);
*atomic_ptr.get_mut() = &mut 5;
assert_eq!(unsafe { *atomic_ptr.load(Ordering::SeqCst) }, 5);

fn into_inner(self) -> *mut T

Consumes the atomic and returns the contained value.

This is safe because passing self by value guarantees that no other threads are concurrently accessing the atomic data.

Examples

use std::sync::atomic::AtomicPtr;

let atomic_ptr = AtomicPtr::new(&mut 5);
assert_eq!(unsafe { *atomic_ptr.into_inner() }, 5);

fn load(&self, order: Ordering) -> *mut T

Loads a value from the pointer.

load takes an Ordering argument which describes the memory ordering of this operation.

Panics

Panics if order is Release or AcqRel.

Examples

use std::sync::atomic::{AtomicPtr, Ordering};

let ptr = &mut 5;
let some_ptr  = AtomicPtr::new(ptr);

let value = some_ptr.load(Ordering::Relaxed);

fn store(&self, ptr: *mut T, order: Ordering)

Stores a value into the pointer.

store takes an Ordering argument which describes the memory ordering of this operation.

Examples

use std::sync::atomic::{AtomicPtr, Ordering};

let ptr = &mut 5;
let some_ptr  = AtomicPtr::new(ptr);

let other_ptr = &mut 10;

some_ptr.store(other_ptr, Ordering::Relaxed);

Panics

Panics if order is Acquire or AcqRel.

fn swap(&self, ptr: *mut T, order: Ordering) -> *mut T

Stores a value into the pointer, returning the old value.

swap takes an Ordering argument which describes the memory ordering of this operation.

Examples

use std::sync::atomic::{AtomicPtr, Ordering};

let ptr = &mut 5;
let some_ptr  = AtomicPtr::new(ptr);

let other_ptr = &mut 10;

let value = some_ptr.swap(other_ptr, Ordering::Relaxed);

fn compare_and_swap(&self,
                    current: *mut T,
                    new: *mut T,
                    order: Ordering)
                    -> *mut T

Stores a value into the pointer 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

use std::sync::atomic::{AtomicPtr, Ordering};

let ptr = &mut 5;
let some_ptr  = AtomicPtr::new(ptr);

let other_ptr   = &mut 10;
let another_ptr = &mut 10;

let value = some_ptr.compare_and_swap(other_ptr, another_ptr, Ordering::Relaxed);

fn compare_exchange(&self,
                    current: *mut T,
                    new: *mut T,
                    success: Ordering,
                    failure: Ordering)
                    -> Result<*mut T, *mut T>

Stores a value into the pointer 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 current.

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

use std::sync::atomic::{AtomicPtr, Ordering};

let ptr = &mut 5;
let some_ptr  = AtomicPtr::new(ptr);

let other_ptr   = &mut 10;
let another_ptr = &mut 10;

let value = some_ptr.compare_exchange(other_ptr, another_ptr,
                                      Ordering::SeqCst, Ordering::Relaxed);

fn compare_exchange_weak(&self,
                         current: *mut T,
                         new: *mut T,
                         success: Ordering,
                         failure: Ordering)
                         -> Result<*mut T, *mut T>

Stores a value into the pointer 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

use std::sync::atomic::{AtomicPtr, Ordering};

let some_ptr = AtomicPtr::new(&mut 5);

let new = &mut 10;
let mut old = some_ptr.load(Ordering::Relaxed);
loop {
    match some_ptr.compare_exchange_weak(old, new, Ordering::SeqCst, Ordering::Relaxed) {
        Ok(_) => break,
        Err(x) => old = x,
    }
}

Trait Implementations

impl<T> Sync for AtomicPtr<T>

impl<T> Send for AtomicPtr<T>

impl<T> Default for AtomicPtr<T>

fn default() -> AtomicPtr<T>

Creates a null AtomicPtr<T>.

impl<T> Debug for AtomicPtr<T>

fn fmt(&self, f: &mut Formatter) -> Result<(), Error>

Formats the value using the given formatter.