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use std::mem;
use std::sync::atomic::AtomicUsize;
use std::sync::atomic::Ordering::SeqCst;
use crossbeam_utils::atomic::AtomicCell;
#[test]
fn is_lock_free() {
struct UsizeWrap(#[allow(dead_code)] usize);
struct U8Wrap(#[allow(dead_code)] bool);
struct I16Wrap(#[allow(dead_code)] i16);
#[repr(align(8))]
struct U64Align8(#[allow(dead_code)] u64);
assert!(AtomicCell::<usize>::is_lock_free());
assert!(AtomicCell::<isize>::is_lock_free());
assert!(AtomicCell::<UsizeWrap>::is_lock_free());
assert!(AtomicCell::<()>::is_lock_free());
assert!(AtomicCell::<u8>::is_lock_free());
assert!(AtomicCell::<i8>::is_lock_free());
assert!(AtomicCell::<bool>::is_lock_free());
assert!(AtomicCell::<U8Wrap>::is_lock_free());
assert!(AtomicCell::<u16>::is_lock_free());
assert!(AtomicCell::<i16>::is_lock_free());
assert!(AtomicCell::<I16Wrap>::is_lock_free());
assert!(AtomicCell::<u32>::is_lock_free());
assert!(AtomicCell::<i32>::is_lock_free());
// Sizes of both types must be equal, and the alignment of `u64` must be greater or equal than
// that of `AtomicU64`. In i686-unknown-linux-gnu, the alignment of `u64` is `4` and alignment
// of `AtomicU64` is `8`, so `AtomicCell<u64>` is not lock-free.
assert_eq!(
AtomicCell::<u64>::is_lock_free(),
cfg!(target_has_atomic = "64") && std::mem::align_of::<u64>() == 8
);
assert_eq!(mem::size_of::<U64Align8>(), 8);
assert_eq!(mem::align_of::<U64Align8>(), 8);
assert_eq!(
AtomicCell::<U64Align8>::is_lock_free(),
cfg!(target_has_atomic = "64")
);
// AtomicU128 is unstable
assert!(!AtomicCell::<u128>::is_lock_free());
}
#[test]
fn const_is_lock_free() {
const _U: bool = AtomicCell::<usize>::is_lock_free();
const _I: bool = AtomicCell::<isize>::is_lock_free();
}
#[test]
fn drops_unit() {
static CNT: AtomicUsize = AtomicUsize::new(0);
CNT.store(0, SeqCst);
#[derive(Debug, PartialEq, Eq)]
struct Foo();
impl Foo {
fn new() -> Foo {
CNT.fetch_add(1, SeqCst);
Foo()
}
}
impl Drop for Foo {
fn drop(&mut self) {
CNT.fetch_sub(1, SeqCst);
}
}
impl Default for Foo {
fn default() -> Foo {
Foo::new()
}
}
let a = AtomicCell::new(Foo::new());
assert_eq!(a.swap(Foo::new()), Foo::new());
assert_eq!(CNT.load(SeqCst), 1);
a.store(Foo::new());
assert_eq!(CNT.load(SeqCst), 1);
assert_eq!(a.swap(Foo::default()), Foo::new());
assert_eq!(CNT.load(SeqCst), 1);
drop(a);
assert_eq!(CNT.load(SeqCst), 0);
}
#[test]
fn drops_u8() {
static CNT: AtomicUsize = AtomicUsize::new(0);
CNT.store(0, SeqCst);
#[derive(Debug, PartialEq, Eq)]
struct Foo(u8);
impl Foo {
fn new(val: u8) -> Foo {
CNT.fetch_add(1, SeqCst);
Foo(val)
}
}
impl Drop for Foo {
fn drop(&mut self) {
CNT.fetch_sub(1, SeqCst);
}
}
impl Default for Foo {
fn default() -> Foo {
Foo::new(0)
}
}
let a = AtomicCell::new(Foo::new(5));
assert_eq!(a.swap(Foo::new(6)), Foo::new(5));
assert_eq!(a.swap(Foo::new(1)), Foo::new(6));
assert_eq!(CNT.load(SeqCst), 1);
a.store(Foo::new(2));
assert_eq!(CNT.load(SeqCst), 1);
assert_eq!(a.swap(Foo::default()), Foo::new(2));
assert_eq!(CNT.load(SeqCst), 1);
assert_eq!(a.swap(Foo::default()), Foo::new(0));
assert_eq!(CNT.load(SeqCst), 1);
drop(a);
assert_eq!(CNT.load(SeqCst), 0);
}
#[test]
fn drops_usize() {
static CNT: AtomicUsize = AtomicUsize::new(0);
CNT.store(0, SeqCst);
#[derive(Debug, PartialEq, Eq)]
struct Foo(usize);
impl Foo {
fn new(val: usize) -> Foo {
CNT.fetch_add(1, SeqCst);
Foo(val)
}
}
impl Drop for Foo {
fn drop(&mut self) {
CNT.fetch_sub(1, SeqCst);
}
}
impl Default for Foo {
fn default() -> Foo {
Foo::new(0)
}
}
let a = AtomicCell::new(Foo::new(5));
assert_eq!(a.swap(Foo::new(6)), Foo::new(5));
assert_eq!(a.swap(Foo::new(1)), Foo::new(6));
assert_eq!(CNT.load(SeqCst), 1);
a.store(Foo::new(2));
assert_eq!(CNT.load(SeqCst), 1);
assert_eq!(a.swap(Foo::default()), Foo::new(2));
assert_eq!(CNT.load(SeqCst), 1);
assert_eq!(a.swap(Foo::default()), Foo::new(0));
assert_eq!(CNT.load(SeqCst), 1);
drop(a);
assert_eq!(CNT.load(SeqCst), 0);
}
#[test]
fn modular_u8() {
#[derive(Clone, Copy, Eq, Debug, Default)]
struct Foo(u8);
impl PartialEq for Foo {
fn eq(&self, other: &Foo) -> bool {
self.0 % 5 == other.0 % 5
}
}
let a = AtomicCell::new(Foo(1));
assert_eq!(a.load(), Foo(1));
assert_eq!(a.swap(Foo(2)), Foo(11));
assert_eq!(a.load(), Foo(52));
a.store(Foo(0));
assert_eq!(a.compare_exchange(Foo(0), Foo(5)), Ok(Foo(100)));
assert_eq!(a.load().0, 5);
assert_eq!(a.compare_exchange(Foo(10), Foo(15)), Ok(Foo(100)));
assert_eq!(a.load().0, 15);
}
#[test]
fn modular_usize() {
#[derive(Clone, Copy, Eq, Debug, Default)]
struct Foo(usize);
impl PartialEq for Foo {
fn eq(&self, other: &Foo) -> bool {
self.0 % 5 == other.0 % 5
}
}
let a = AtomicCell::new(Foo(1));
assert_eq!(a.load(), Foo(1));
assert_eq!(a.swap(Foo(2)), Foo(11));
assert_eq!(a.load(), Foo(52));
a.store(Foo(0));
assert_eq!(a.compare_exchange(Foo(0), Foo(5)), Ok(Foo(100)));
assert_eq!(a.load().0, 5);
assert_eq!(a.compare_exchange(Foo(10), Foo(15)), Ok(Foo(100)));
assert_eq!(a.load().0, 15);
}
#[test]
fn garbage_padding() {
#[derive(Copy, Clone, Eq, PartialEq)]
struct Object {
a: i64,
b: i32,
}
let cell = AtomicCell::new(Object { a: 0, b: 0 });
let _garbage = [0xfe, 0xfe, 0xfe, 0xfe, 0xfe]; // Needed
let next = Object { a: 0, b: 0 };
let prev = cell.load();
assert!(cell.compare_exchange(prev, next).is_ok());
println!();
}
#[test]
fn const_atomic_cell_new() {
static CELL: AtomicCell<usize> = AtomicCell::new(0);
CELL.store(1);
assert_eq!(CELL.load(), 1);
}
macro_rules! test_arithmetic {
($test_name:ident, $ty:ident) => {
#[test]
fn $test_name() {
let a: AtomicCell<$ty> = AtomicCell::new(7);
assert_eq!(a.fetch_add(3), 7);
assert_eq!(a.load(), 10);
assert_eq!(a.fetch_sub(3), 10);
assert_eq!(a.load(), 7);
assert_eq!(a.fetch_and(3), 7);
assert_eq!(a.load(), 3);
assert_eq!(a.fetch_or(16), 3);
assert_eq!(a.load(), 19);
assert_eq!(a.fetch_xor(2), 19);
assert_eq!(a.load(), 17);
assert_eq!(a.fetch_max(18), 17);
assert_eq!(a.load(), 18);
assert_eq!(a.fetch_min(17), 18);
assert_eq!(a.load(), 17);
assert_eq!(a.fetch_nand(7), 17);
assert_eq!(a.load(), !(17 & 7));
}
};
}
test_arithmetic!(arithmetic_u8, u8);
test_arithmetic!(arithmetic_i8, i8);
test_arithmetic!(arithmetic_u16, u16);
test_arithmetic!(arithmetic_i16, i16);
test_arithmetic!(arithmetic_u32, u32);
test_arithmetic!(arithmetic_i32, i32);
test_arithmetic!(arithmetic_u64, u64);
test_arithmetic!(arithmetic_i64, i64);
test_arithmetic!(arithmetic_u128, u128);
test_arithmetic!(arithmetic_i128, i128);
#[cfg_attr(miri, ignore)] // TODO
#[test]
fn issue_748() {
#[allow(dead_code)]
#[repr(align(8))]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum Test {
Field(u32),
FieldLess,
}
assert_eq!(mem::size_of::<Test>(), 8);
assert_eq!(
AtomicCell::<Test>::is_lock_free(),
cfg!(target_has_atomic = "64")
);
let x = AtomicCell::new(Test::FieldLess);
assert_eq!(x.load(), Test::FieldLess);
}
#[test]
fn issue_833() {
use std::num::NonZeroU128;
use std::sync::atomic::{AtomicBool, Ordering};
use std::thread;
#[cfg(miri)]
const N: usize = 10_000;
#[cfg(not(miri))]
const N: usize = 1_000_000;
#[allow(dead_code)]
enum Enum {
NeverConstructed,
Cell(AtomicCell<NonZeroU128>),
}
static STATIC: Enum = Enum::Cell(AtomicCell::new(match NonZeroU128::new(1) {
Some(nonzero) => nonzero,
None => unreachable!(),
}));
static FINISHED: AtomicBool = AtomicBool::new(false);
let handle = thread::spawn(|| {
let cell = match &STATIC {
Enum::NeverConstructed => unreachable!(),
Enum::Cell(cell) => cell,
};
let x = NonZeroU128::new(0xFFFF_FFFF_FFFF_FFFF_0000_0000_0000_0000).unwrap();
let y = NonZeroU128::new(0x0000_0000_0000_0000_FFFF_FFFF_FFFF_FFFF).unwrap();
while !FINISHED.load(Ordering::Relaxed) {
cell.store(x);
cell.store(y);
}
});
for _ in 0..N {
if let Enum::NeverConstructed = STATIC {
unreachable!(":(");
}
}
FINISHED.store(true, Ordering::Relaxed);
handle.join().unwrap();
}