#[repr(C, align(8))]pub struct AtomicU64 { /* private fields */ }Expand description
An integer type which can be safely shared between threads.
This type has the same
size and bit validity
as the underlying integer type, u64.
However, the alignment of this type is always equal to its size, even on targets where u64 has a lesser alignment.
For more about the differences between atomic types and non-atomic types as well as information about the portability of this type, please see the module-level documentation.
Note: This type is only available on platforms that support
atomic loads and stores of u64.
Implementations§
Source§impl AtomicU64
 
impl AtomicU64
1.34.0 (const: 1.34.0) · Sourcepub const fn new(v: u64) -> AtomicU64
 
pub const fn new(v: u64) -> AtomicU64
Creates a new atomic integer.
§Examples
use std::sync::atomic::AtomicU64;
let atomic_forty_two = AtomicU64::new(42);1.75.0 (const: 1.84.0) · Sourcepub const unsafe fn from_ptr<'a>(ptr: *mut u64) -> &'a AtomicU64
 
pub const unsafe fn from_ptr<'a>(ptr: *mut u64) -> &'a AtomicU64
Creates a new reference to an atomic integer from a pointer.
§Examples
use std::sync::atomic::{self, AtomicU64};
// Get a pointer to an allocated value
let ptr: *mut u64 = Box::into_raw(Box::new(0));
assert!(ptr.cast::<AtomicU64>().is_aligned());
{
    // Create an atomic view of the allocated value
    let atomic = unsafe {AtomicU64::from_ptr(ptr) };
    // Use `atomic` for atomic operations, possibly share it with other threads
    atomic.store(1, atomic::Ordering::Relaxed);
}
// It's ok to non-atomically access the value behind `ptr`,
// since the reference to the atomic ended its lifetime in the block above
assert_eq!(unsafe { *ptr }, 1);
// Deallocate the value
unsafe { drop(Box::from_raw(ptr)) }§Safety
- ptrmust be aligned to- align_of::<AtomicU64>()(note that on some platforms this can be bigger than- align_of::<u64>()).
- ptrmust be valid for both reads and writes for the whole lifetime- 'a.
- You must adhere to the Memory model for atomic accesses. In particular, it is not allowed to mix atomic and non-atomic accesses, or atomic accesses of different sizes, without synchronization.
1.34.0 · Sourcepub fn get_mut(&mut self) -> &mut u64
 
pub fn get_mut(&mut self) -> &mut u64
Returns a mutable reference to the underlying integer.
This is safe because the mutable reference guarantees that no other threads are concurrently accessing the atomic data.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let mut some_var = AtomicU64::new(10);
assert_eq!(*some_var.get_mut(), 10);
*some_var.get_mut() = 5;
assert_eq!(some_var.load(Ordering::SeqCst), 5);Sourcepub fn from_mut(v: &mut u64) -> &mut AtomicU64
 🔬This is a nightly-only experimental API. (atomic_from_mut)Available on target_has_atomic_equal_alignment="64" only.
pub fn from_mut(v: &mut u64) -> &mut AtomicU64
atomic_from_mut)target_has_atomic_equal_alignment="64" only.Get atomic access to a &mut u64.
Note: This function is only available on targets where AtomicU64 has the same alignment as u64.
§Examples
#![feature(atomic_from_mut)]
use std::sync::atomic::{AtomicU64, Ordering};
let mut some_int = 123;
let a = AtomicU64::from_mut(&mut some_int);
a.store(100, Ordering::Relaxed);
assert_eq!(some_int, 100);Sourcepub fn get_mut_slice(this: &mut [AtomicU64]) -> &mut [u64]
 🔬This is a nightly-only experimental API. (atomic_from_mut)
pub fn get_mut_slice(this: &mut [AtomicU64]) -> &mut [u64]
atomic_from_mut)Get non-atomic access to a &mut [AtomicU64] slice
This is safe because the mutable reference guarantees that no other threads are concurrently accessing the atomic data.
§Examples
#![feature(atomic_from_mut)]
use std::sync::atomic::{AtomicU64, Ordering};
let mut some_ints = [const { AtomicU64::new(0) }; 10];
let view: &mut [u64] = AtomicU64::get_mut_slice(&mut some_ints);
assert_eq!(view, [0; 10]);
view
    .iter_mut()
    .enumerate()
    .for_each(|(idx, int)| *int = idx as _);
std::thread::scope(|s| {
    some_ints
        .iter()
        .enumerate()
        .for_each(|(idx, int)| {
            s.spawn(move || assert_eq!(int.load(Ordering::Relaxed), idx as _));
        })
});Sourcepub fn from_mut_slice(v: &mut [u64]) -> &mut [AtomicU64]
 🔬This is a nightly-only experimental API. (atomic_from_mut)Available on target_has_atomic_equal_alignment="64" only.
pub fn from_mut_slice(v: &mut [u64]) -> &mut [AtomicU64]
atomic_from_mut)target_has_atomic_equal_alignment="64" only.Get atomic access to a &mut [u64] slice.
§Examples
#![feature(atomic_from_mut)]
use std::sync::atomic::{AtomicU64, Ordering};
let mut some_ints = [0; 10];
let a = &*AtomicU64::from_mut_slice(&mut some_ints);
std::thread::scope(|s| {
    for i in 0..a.len() {
        s.spawn(move || a[i].store(i as _, Ordering::Relaxed));
    }
});
for (i, n) in some_ints.into_iter().enumerate() {
    assert_eq!(i, n as usize);
}1.34.0 (const: 1.79.0) · Sourcepub const fn into_inner(self) -> u64
 
pub const fn into_inner(self) -> u64
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::AtomicU64;
let some_var = AtomicU64::new(5);
assert_eq!(some_var.into_inner(), 5);1.34.0 · Sourcepub fn load(&self, order: Ordering) -> u64
 
pub fn load(&self, order: Ordering) -> u64
Loads a value from the atomic integer.
load takes an Ordering argument which describes the memory ordering of this operation.
Possible values are SeqCst, Acquire and Relaxed.
§Panics
Panics if order is Release or AcqRel.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let some_var = AtomicU64::new(5);
assert_eq!(some_var.load(Ordering::Relaxed), 5);1.34.0 · Sourcepub fn store(&self, val: u64, order: Ordering)
 
pub fn store(&self, val: u64, order: Ordering)
Stores a value into the atomic integer.
store takes an Ordering argument which describes the memory ordering of this operation.
Possible values are SeqCst, Release and Relaxed.
§Panics
Panics if order is Acquire or AcqRel.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let some_var = AtomicU64::new(5);
some_var.store(10, Ordering::Relaxed);
assert_eq!(some_var.load(Ordering::Relaxed), 10);1.34.0 · Sourcepub fn swap(&self, val: u64, order: Ordering) -> u64
 Available on target_has_atomic="64" only.
pub fn swap(&self, val: u64, order: Ordering) -> u64
target_has_atomic="64" only.Stores a value into the atomic integer, returning the previous value.
swap takes an Ordering argument which describes the memory ordering
of this operation. All ordering modes are possible. Note that using
Acquire makes the store part of this operation Relaxed, and
using Release makes the load part Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let some_var = AtomicU64::new(5);
assert_eq!(some_var.swap(10, Ordering::Relaxed), 5);1.34.0 · Sourcepub fn compare_and_swap(&self, current: u64, new: u64, order: Ordering) -> u64
 👎Deprecated since 1.50.0: Use compare_exchange or compare_exchange_weak insteadAvailable on target_has_atomic="64" only.
pub fn compare_and_swap(&self, current: u64, new: u64, order: Ordering) -> u64
compare_exchange or compare_exchange_weak insteadtarget_has_atomic="64" only.Stores a value into the atomic integer 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. Notice that even when using AcqRel, the operation
might fail and hence just perform an Acquire load, but not have Release semantics.
Using Acquire makes the store part of this operation Relaxed if it
happens, and using Release makes the load part Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Migrating to compare_exchange and compare_exchange_weak
compare_and_swap is equivalent to compare_exchange with the following mapping for
memory orderings:
| Original | Success | Failure | 
|---|---|---|
| Relaxed | Relaxed | Relaxed | 
| Acquire | Acquire | Acquire | 
| Release | Release | Relaxed | 
| AcqRel | AcqRel | Acquire | 
| SeqCst | SeqCst | SeqCst | 
compare_and_swap and compare_exchange also differ in their return type. You can use
compare_exchange(...).unwrap_or_else(|x| x) to recover the behavior of compare_and_swap,
but in most cases it is more idiomatic to check whether the return value is Ok or Err
rather than to infer success vs failure based on the value that was read.
During migration, consider whether it makes sense to use compare_exchange_weak instead.
compare_exchange_weak is allowed to fail spuriously even when the comparison succeeds,
which allows the compiler to generate better assembly code when the compare and swap
is used in a loop.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let some_var = AtomicU64::new(5);
assert_eq!(some_var.compare_and_swap(5, 10, Ordering::Relaxed), 5);
assert_eq!(some_var.load(Ordering::Relaxed), 10);
assert_eq!(some_var.compare_and_swap(6, 12, Ordering::Relaxed), 10);
assert_eq!(some_var.load(Ordering::Relaxed), 10);1.34.0 · Sourcepub fn compare_exchange(
    &self,
    current: u64,
    new: u64,
    success: Ordering,
    failure: Ordering,
) -> Result<u64, u64>
 Available on target_has_atomic="64" only.
pub fn compare_exchange( &self, current: u64, new: u64, success: Ordering, failure: Ordering, ) -> Result<u64, u64>
target_has_atomic="64" only.Stores a value into the atomic integer 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. success describes the required ordering for the
read-modify-write operation that takes place if the comparison with current succeeds.
failure describes the required ordering for the load operation that takes place when
the comparison fails. Using Acquire as success ordering makes the store part
of this operation Relaxed, and using Release makes the successful load
Relaxed. The failure ordering can only be SeqCst, Acquire or Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let some_var = AtomicU64::new(5);
assert_eq!(some_var.compare_exchange(5, 10,
                                     Ordering::Acquire,
                                     Ordering::Relaxed),
           Ok(5));
assert_eq!(some_var.load(Ordering::Relaxed), 10);
assert_eq!(some_var.compare_exchange(6, 12,
                                     Ordering::SeqCst,
                                     Ordering::Acquire),
           Err(10));
assert_eq!(some_var.load(Ordering::Relaxed), 10);1.34.0 · Sourcepub fn compare_exchange_weak(
    &self,
    current: u64,
    new: u64,
    success: Ordering,
    failure: Ordering,
) -> Result<u64, u64>
 Available on target_has_atomic="64" only.
pub fn compare_exchange_weak( &self, current: u64, new: u64, success: Ordering, failure: Ordering, ) -> Result<u64, u64>
target_has_atomic="64" only.Stores a value into the atomic integer if the current value is the same as
the current value.
Unlike AtomicU64::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. success describes the required ordering for the
read-modify-write operation that takes place if the comparison with current succeeds.
failure describes the required ordering for the load operation that takes place when
the comparison fails. Using Acquire as success ordering makes the store part
of this operation Relaxed, and using Release makes the successful load
Relaxed. The failure ordering can only be SeqCst, Acquire or Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let val = AtomicU64::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,
    }
}1.34.0 · Sourcepub fn fetch_add(&self, val: u64, order: Ordering) -> u64
 Available on target_has_atomic="64" only.
pub fn fetch_add(&self, val: u64, order: Ordering) -> u64
target_has_atomic="64" only.Adds to the current value, returning the previous value.
This operation wraps around on overflow.
fetch_add takes an Ordering argument which describes the memory ordering
of this operation. All ordering modes are possible. Note that using
Acquire makes the store part of this operation Relaxed, and
using Release makes the load part Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let foo = AtomicU64::new(0);
assert_eq!(foo.fetch_add(10, Ordering::SeqCst), 0);
assert_eq!(foo.load(Ordering::SeqCst), 10);1.34.0 · Sourcepub fn fetch_sub(&self, val: u64, order: Ordering) -> u64
 Available on target_has_atomic="64" only.
pub fn fetch_sub(&self, val: u64, order: Ordering) -> u64
target_has_atomic="64" only.Subtracts from the current value, returning the previous value.
This operation wraps around on overflow.
fetch_sub takes an Ordering argument which describes the memory ordering
of this operation. All ordering modes are possible. Note that using
Acquire makes the store part of this operation Relaxed, and
using Release makes the load part Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let foo = AtomicU64::new(20);
assert_eq!(foo.fetch_sub(10, Ordering::SeqCst), 20);
assert_eq!(foo.load(Ordering::SeqCst), 10);1.34.0 · Sourcepub fn fetch_and(&self, val: u64, order: Ordering) -> u64
 Available on target_has_atomic="64" only.
pub fn fetch_and(&self, val: u64, order: Ordering) -> u64
target_has_atomic="64" only.Bitwise “and” with the current value.
Performs a bitwise “and” operation on the current value and the argument val, and
sets the new value to the result.
Returns the previous value.
fetch_and takes an Ordering argument which describes the memory ordering
of this operation. All ordering modes are possible. Note that using
Acquire makes the store part of this operation Relaxed, and
using Release makes the load part Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let foo = AtomicU64::new(0b101101);
assert_eq!(foo.fetch_and(0b110011, Ordering::SeqCst), 0b101101);
assert_eq!(foo.load(Ordering::SeqCst), 0b100001);1.34.0 · Sourcepub fn fetch_nand(&self, val: u64, order: Ordering) -> u64
 Available on target_has_atomic="64" only.
pub fn fetch_nand(&self, val: u64, order: Ordering) -> u64
target_has_atomic="64" only.Bitwise “nand” with the current value.
Performs a bitwise “nand” operation on the current value and the argument val, and
sets the new value to the result.
Returns the previous value.
fetch_nand takes an Ordering argument which describes the memory ordering
of this operation. All ordering modes are possible. Note that using
Acquire makes the store part of this operation Relaxed, and
using Release makes the load part Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let foo = AtomicU64::new(0x13);
assert_eq!(foo.fetch_nand(0x31, Ordering::SeqCst), 0x13);
assert_eq!(foo.load(Ordering::SeqCst), !(0x13 & 0x31));1.34.0 · Sourcepub fn fetch_or(&self, val: u64, order: Ordering) -> u64
 Available on target_has_atomic="64" only.
pub fn fetch_or(&self, val: u64, order: Ordering) -> u64
target_has_atomic="64" only.Bitwise “or” with the current value.
Performs a bitwise “or” operation on the current value and the argument val, and
sets the new value to the result.
Returns the previous value.
fetch_or takes an Ordering argument which describes the memory ordering
of this operation. All ordering modes are possible. Note that using
Acquire makes the store part of this operation Relaxed, and
using Release makes the load part Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let foo = AtomicU64::new(0b101101);
assert_eq!(foo.fetch_or(0b110011, Ordering::SeqCst), 0b101101);
assert_eq!(foo.load(Ordering::SeqCst), 0b111111);1.34.0 · Sourcepub fn fetch_xor(&self, val: u64, order: Ordering) -> u64
 Available on target_has_atomic="64" only.
pub fn fetch_xor(&self, val: u64, order: Ordering) -> u64
target_has_atomic="64" only.Bitwise “xor” with the current value.
Performs a bitwise “xor” operation on the current value and the argument val, and
sets the new value to the result.
Returns the previous value.
fetch_xor takes an Ordering argument which describes the memory ordering
of this operation. All ordering modes are possible. Note that using
Acquire makes the store part of this operation Relaxed, and
using Release makes the load part Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let foo = AtomicU64::new(0b101101);
assert_eq!(foo.fetch_xor(0b110011, Ordering::SeqCst), 0b101101);
assert_eq!(foo.load(Ordering::SeqCst), 0b011110);1.45.0 · Sourcepub fn fetch_update<F>(
    &self,
    set_order: Ordering,
    fetch_order: Ordering,
    f: F,
) -> Result<u64, u64>
 Available on target_has_atomic="64" only.
pub fn fetch_update<F>( &self, set_order: Ordering, fetch_order: Ordering, f: F, ) -> Result<u64, u64>
target_has_atomic="64" only.Fetches the value, and applies a function to it that returns an optional
new value. Returns a Result of Ok(previous_value) if the function returned Some(_), else
Err(previous_value).
Note: This may call the function multiple times if the value has been changed from other threads in
the meantime, as long as the function returns Some(_), but the function will have been applied
only once to the stored value.
fetch_update takes two Ordering arguments to describe the memory ordering of this operation.
The first describes the required ordering for when the operation finally succeeds while the second
describes the required ordering for loads. These correspond to the success and failure orderings of
AtomicU64::compare_exchange
respectively.
Using Acquire as success ordering makes the store part
of this operation Relaxed, and using Release makes the final successful load
Relaxed. The (failed) load ordering can only be SeqCst, Acquire or Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Considerations
This method is not magic; it is not provided by the hardware.
It is implemented in terms of
AtomicU64::compare_exchange_weak,
and suffers from the same drawbacks.
In particular, this method will not circumvent the ABA Problem.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let x = AtomicU64::new(7);
assert_eq!(x.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |_| None), Err(7));
assert_eq!(x.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |x| Some(x + 1)), Ok(7));
assert_eq!(x.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |x| Some(x + 1)), Ok(8));
assert_eq!(x.load(Ordering::SeqCst), 9);Sourcepub fn try_update(
    &self,
    set_order: Ordering,
    fetch_order: Ordering,
    f: impl FnMut(u64) -> Option<u64>,
) -> Result<u64, u64>
 🔬This is a nightly-only experimental API. (atomic_try_update)Available on target_has_atomic="64" only.
pub fn try_update( &self, set_order: Ordering, fetch_order: Ordering, f: impl FnMut(u64) -> Option<u64>, ) -> Result<u64, u64>
atomic_try_update)target_has_atomic="64" only.Fetches the value, and applies a function to it that returns an optional
new value. Returns a Result of Ok(previous_value) if the function returned Some(_), else
Err(previous_value).
See also: update.
Note: This may call the function multiple times if the value has been changed from other threads in
the meantime, as long as the function returns Some(_), but the function will have been applied
only once to the stored value.
try_update takes two Ordering arguments to describe the memory ordering of this operation.
The first describes the required ordering for when the operation finally succeeds while the second
describes the required ordering for loads. These correspond to the success and failure orderings of
AtomicU64::compare_exchange
respectively.
Using Acquire as success ordering makes the store part
of this operation Relaxed, and using Release makes the final successful load
Relaxed. The (failed) load ordering can only be SeqCst, Acquire or Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Considerations
This method is not magic; it is not provided by the hardware.
It is implemented in terms of
AtomicU64::compare_exchange_weak,
and suffers from the same drawbacks.
In particular, this method will not circumvent the ABA Problem.
§Examples
#![feature(atomic_try_update)]
use std::sync::atomic::{AtomicU64, Ordering};
let x = AtomicU64::new(7);
assert_eq!(x.try_update(Ordering::SeqCst, Ordering::SeqCst, |_| None), Err(7));
assert_eq!(x.try_update(Ordering::SeqCst, Ordering::SeqCst, |x| Some(x + 1)), Ok(7));
assert_eq!(x.try_update(Ordering::SeqCst, Ordering::SeqCst, |x| Some(x + 1)), Ok(8));
assert_eq!(x.load(Ordering::SeqCst), 9);Sourcepub fn update(
    &self,
    set_order: Ordering,
    fetch_order: Ordering,
    f: impl FnMut(u64) -> u64,
) -> u64
 🔬This is a nightly-only experimental API. (atomic_try_update)Available on target_has_atomic="64" only.
pub fn update( &self, set_order: Ordering, fetch_order: Ordering, f: impl FnMut(u64) -> u64, ) -> u64
atomic_try_update)target_has_atomic="64" only.Fetches the value, applies a function to it that it return a new value. The new value is stored and the old value is returned.
See also: try_update.
Note: This may call the function multiple times if the value has been changed from other threads in the meantime, but the function will have been applied only once to the stored value.
update takes two Ordering arguments to describe the memory ordering of this operation.
The first describes the required ordering for when the operation finally succeeds while the second
describes the required ordering for loads. These correspond to the success and failure orderings of
AtomicU64::compare_exchange
respectively.
Using Acquire as success ordering makes the store part
of this operation Relaxed, and using Release makes the final successful load
Relaxed. The (failed) load ordering can only be SeqCst, Acquire or Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Considerations
This method is not magic; it is not provided by the hardware.
It is implemented in terms of
AtomicU64::compare_exchange_weak,
and suffers from the same drawbacks.
In particular, this method will not circumvent the ABA Problem.
§Examples
#![feature(atomic_try_update)]
use std::sync::atomic::{AtomicU64, Ordering};
let x = AtomicU64::new(7);
assert_eq!(x.update(Ordering::SeqCst, Ordering::SeqCst, |x| x + 1), 7);
assert_eq!(x.update(Ordering::SeqCst, Ordering::SeqCst, |x| x + 1), 8);
assert_eq!(x.load(Ordering::SeqCst), 9);1.45.0 · Sourcepub fn fetch_max(&self, val: u64, order: Ordering) -> u64
 Available on target_has_atomic="64" only.
pub fn fetch_max(&self, val: u64, order: Ordering) -> u64
target_has_atomic="64" only.Maximum with the current value.
Finds the maximum of the current value and the argument val, and
sets the new value to the result.
Returns the previous value.
fetch_max takes an Ordering argument which describes the memory ordering
of this operation. All ordering modes are possible. Note that using
Acquire makes the store part of this operation Relaxed, and
using Release makes the load part Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let foo = AtomicU64::new(23);
assert_eq!(foo.fetch_max(42, Ordering::SeqCst), 23);
assert_eq!(foo.load(Ordering::SeqCst), 42);If you want to obtain the maximum value in one step, you can use the following:
use std::sync::atomic::{AtomicU64, Ordering};
let foo = AtomicU64::new(23);
let bar = 42;
let max_foo = foo.fetch_max(bar, Ordering::SeqCst).max(bar);
assert!(max_foo == 42);1.45.0 · Sourcepub fn fetch_min(&self, val: u64, order: Ordering) -> u64
 Available on target_has_atomic="64" only.
pub fn fetch_min(&self, val: u64, order: Ordering) -> u64
target_has_atomic="64" only.Minimum with the current value.
Finds the minimum of the current value and the argument val, and
sets the new value to the result.
Returns the previous value.
fetch_min takes an Ordering argument which describes the memory ordering
of this operation. All ordering modes are possible. Note that using
Acquire makes the store part of this operation Relaxed, and
using Release makes the load part Relaxed.
Note: This method is only available on platforms that support atomic operations on
u64.
§Examples
use std::sync::atomic::{AtomicU64, Ordering};
let foo = AtomicU64::new(23);
assert_eq!(foo.fetch_min(42, Ordering::Relaxed), 23);
assert_eq!(foo.load(Ordering::Relaxed), 23);
assert_eq!(foo.fetch_min(22, Ordering::Relaxed), 23);
assert_eq!(foo.load(Ordering::Relaxed), 22);If you want to obtain the minimum value in one step, you can use the following:
use std::sync::atomic::{AtomicU64, Ordering};
let foo = AtomicU64::new(23);
let bar = 12;
let min_foo = foo.fetch_min(bar, Ordering::SeqCst).min(bar);
assert_eq!(min_foo, 12);1.70.0 (const: 1.70.0) · Sourcepub const fn as_ptr(&self) -> *mut u64
 
pub const fn as_ptr(&self) -> *mut u64
Returns a mutable pointer to the underlying integer.
Doing non-atomic reads and writes on the resulting integer can be a data race.
This method is mostly useful for FFI, where the function signature may use
*mut u64 instead of &AtomicU64.
Returning an *mut pointer from a shared reference to this atomic is safe because the
atomic types work with interior mutability. All modifications of an atomic change the value
through a shared reference, and can do so safely as long as they use atomic operations. Any
use of the returned raw pointer requires an unsafe block and still has to uphold the same
restriction: operations on it must be atomic.
§Examples
use std::sync::atomic::AtomicU64;
extern "C" {
    fn my_atomic_op(arg: *mut u64);
}
let atomic = AtomicU64::new(1);
// SAFETY: Safe as long as `my_atomic_op` is atomic.
unsafe {
    my_atomic_op(atomic.as_ptr());
}Trait Implementations§
§impl BitStore for AtomicU64
 
impl BitStore for AtomicU64
§const ALIGNED_TO_SIZE: [(); 1]
 
const ALIGNED_TO_SIZE: [(); 1]
§const ALIAS_WIDTH: [(); 1]
 
const ALIAS_WIDTH: [(); 1]
Self and Self::Alias be equal
in representation. This is true by fiat for all types except the
unsigned integers. Read more§type Mem = u64
 
type Mem = u64
BitSlice. It
is always one of the unsigned integer fundamentals.§type Access = AtomicU64
 
type Access = AtomicU64
Self::Mem value between the processor and the memory system. Read more§type Alias = AtomicU64
 
type Alias = AtomicU64
BitStore implementor that is known to be alias-safe. It is
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It must have the same underlying memory type, and can only change access
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type Unalias = AtomicU64
::Alias. It is used when a BitSlice removes the
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fn new(value: <AtomicU64 as BitStore>::Mem) -> AtomicU64
BitStore type.§fn load_value(&self) -> <AtomicU64 as BitStore>::Mem
 
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::Access
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fn store_value(&mut self, value: <AtomicU64 as BitStore>::Mem)
::Access
constraints.Source§impl<'de> Deserialize<'de> for AtomicU64
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    deserializer: D,
) -> Result<AtomicU64, <D as Deserializer<'de>>::Error>where
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fn deserialize<D>(
    deserializer: D,
) -> Result<AtomicU64, <D as Deserializer<'de>>::Error>where
    D: Deserializer<'de>,
§impl Radium for AtomicU64
 
impl Radium for AtomicU64
type Item = u64
§fn into_inner(self) -> u64
 
fn into_inner(self) -> u64
§fn swap(&self, value: u64, order: Ordering) -> u64
 
fn swap(&self, value: u64, order: Ordering) -> u64
§fn compare_and_swap(&self, current: u64, new: u64, order: Ordering) -> u64
 
fn compare_and_swap(&self, current: u64, new: u64, order: Ordering) -> u64
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    &self,
    current: u64,
    new: u64,
    success: Ordering,
    failure: Ordering,
) -> Result<u64, u64>
 
fn compare_exchange( &self, current: u64, new: u64, success: Ordering, failure: Ordering, ) -> Result<u64, u64>
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    &self,
    current: u64,
    new: u64,
    success: Ordering,
    failure: Ordering,
) -> Result<u64, u64>
 
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current value. Read more§fn fetch_update<F>(
    &self,
    set_order: Ordering,
    fetch_order: Ordering,
    f: F,
) -> Result<u64, u64>
 
fn fetch_update<F>( &self, set_order: Ordering, fetch_order: Ordering, f: F, ) -> Result<u64, u64>
§fn fetch_and(&self, value: u64, order: Ordering) -> u64
 
fn fetch_and(&self, value: u64, order: Ordering) -> u64
value, and stores the result in self. Read more§fn fetch_nand(&self, value: u64, order: Ordering) -> u64
 
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value, and stores the result in self. Read more§fn fetch_or(&self, value: u64, order: Ordering) -> u64
 
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value, and stores the result in self. Read more§fn fetch_xor(&self, value: u64, order: Ordering) -> u64
 
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value, and stores the result in self. Read moreSource§impl Serialize for AtomicU64
Available on no_target_has_atomic or target_has_atomic="64" only. 
impl Serialize for AtomicU64
no_target_has_atomic or target_has_atomic="64" only.Source§fn serialize<S>(
    &self,
    serializer: S,
) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>where
    S: Serializer,
 
fn serialize<S>(
    &self,
    serializer: S,
) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>where
    S: Serializer,
impl RefUnwindSafe for AtomicU64
target_has_atomic_load_store="64" only.impl Sync for AtomicU64
Auto Trait Implementations§
impl !Freeze for AtomicU64
impl Send for AtomicU64
impl Unpin for AtomicU64
impl UnwindSafe for AtomicU64
Blanket Implementations§
§impl<A> BitAccess for Awhere
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impl<A> BitAccess for Awhere
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    <A as Radium>::Item: BitRegister,
§fn clear_bits(&self, mask: BitMask<Self::Item>) -> Self::Item
 
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1. Read more§fn invert_bits(&self, mask: BitMask<Self::Item>) -> Self::Item
 
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§fn write_bit<O>(&self, index: BitIdx<Self::Item>, value: bool) -> boolwhere
    O: BitOrder,
 
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    O: BitOrder,
§fn get_writers(
    value: bool,
) -> for<'a> fn(_: &'a Self, _: BitMask<Self::Item>) -> Self::Item
 
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    T: BitStore,
 
impl<T> BitView for Twhere
    T: BitStore,
§fn view_bits<O>(&self) -> &BitSlice<T, O> ⓘwhere
    O: BitOrder,
 
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    O: BitOrder,
§fn try_view_bits<O>(&self) -> Result<&BitSlice<T, O>, BitSpanError<T>>where
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    &mut self,
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    &mut self,
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§impl<T> BitViewSized for Twhere
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§fn into_bitarray<O>(self) -> BitArray<Self, O>where
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