diff options
author | Chris Wailes <chriswailes@google.com> | 2023-01-25 20:55:09 +0000 |
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committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | 2023-01-25 20:55:09 +0000 |
commit | 6d21583f4739e5708e505c0eda72d382149b77f3 (patch) | |
tree | 5b03406c5682a43b22a65a82e3251ce28b307456 | |
parent | 7bcf6c4202362c863d314be4a9fa9dce3d62db42 (diff) | |
parent | 110179d64c3d5e7274414b09fc9e8eeaafa0847e (diff) | |
download | atomic-6d21583f4739e5708e505c0eda72d382149b77f3.tar.gz |
Initial checkin of atomic crate version 0.5.1 am: a620c92011 am: ec06baafd6 am: 110179d64c
Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/atomic/+/2399163
Change-Id: Ie623453d443610c09d29c0960b7ab878ec253a4b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
-rw-r--r-- | Android.bp | 34 | ||||
-rw-r--r-- | Cargo.toml | 29 | ||||
-rw-r--r-- | Cargo.toml.orig | 19 | ||||
l--------- | LICENSE | 1 | ||||
-rw-r--r-- | LICENSE-APACHE | 201 | ||||
-rw-r--r-- | LICENSE-MIT | 25 | ||||
-rw-r--r-- | METADATA | 20 | ||||
-rw-r--r-- | MODULE_LICENSE_APACHE2 | 0 | ||||
-rw-r--r-- | OWNERS | 1 | ||||
-rw-r--r-- | README.md | 42 | ||||
-rw-r--r-- | build.rs | 16 | ||||
-rw-r--r-- | cargo2android.json | 10 | ||||
-rw-r--r-- | src/fallback.rs | 196 | ||||
-rw-r--r-- | src/lib.rs | 711 | ||||
-rw-r--r-- | src/ops.rs | 296 |
15 files changed, 1601 insertions, 0 deletions
diff --git a/Android.bp b/Android.bp new file mode 100644 index 0000000..7abf8de --- /dev/null +++ b/Android.bp @@ -0,0 +1,34 @@ +// This file is generated by cargo2android.py --config cargo2android.json. +// Do not modify this file as changes will be overridden on upgrade. + + + +rust_library { + name: "libatomic_rust", + stem: "libatomic", + // has rustc warnings + host_supported: true, + crate_name: "atomic", + cargo_env_compat: true, + cargo_pkg_version: "0.5.1", + srcs: ["src/lib.rs"], + edition: "2018", + features: [ + "fallback", + "std", + ], + cfgs: [ + "has_atomic_i16", + "has_atomic_i32", + "has_atomic_i64", + "has_atomic_i8", + "has_atomic_u16", + "has_atomic_u32", + "has_atomic_u64", + "has_atomic_u8", + ], + apex_available: [ + "//apex_available:platform", + "com.android.virt", + ], +} diff --git a/Cargo.toml b/Cargo.toml new file mode 100644 index 0000000..fedd21b --- /dev/null +++ b/Cargo.toml @@ -0,0 +1,29 @@ +# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO +# +# When uploading crates to the registry Cargo will automatically +# "normalize" Cargo.toml files for maximal compatibility +# with all versions of Cargo and also rewrite `path` dependencies +# to registry (e.g., crates.io) dependencies. +# +# If you are reading this file be aware that the original Cargo.toml +# will likely look very different (and much more reasonable). +# See Cargo.toml.orig for the original contents. + +[package] +edition = "2018" +name = "atomic" +version = "0.5.1" +authors = ["Amanieu d'Antras <amanieu@gmail.com>"] +description = "Generic Atomic<T> wrapper type" +documentation = "https://amanieu.github.io/atomic-rs/atomic/index.html" +readme = "README.md" +keywords = ["atomic", "no_std"] +license = "Apache-2.0/MIT" +repository = "https://github.com/Amanieu/atomic-rs" +[build-dependencies.autocfg] +version = "1" + +[features] +default = ["fallback"] +fallback = [] +std = [] diff --git a/Cargo.toml.orig b/Cargo.toml.orig new file mode 100644 index 0000000..80b613b --- /dev/null +++ b/Cargo.toml.orig @@ -0,0 +1,19 @@ +[package] +name = "atomic" +version = "0.5.1" +edition = "2018" +authors = ["Amanieu d'Antras <amanieu@gmail.com>"] +description = "Generic Atomic<T> wrapper type" +documentation = "https://amanieu.github.io/atomic-rs/atomic/index.html" +license = "Apache-2.0/MIT" +repository = "https://github.com/Amanieu/atomic-rs" +readme = "README.md" +keywords = ["atomic", "no_std"] + +[features] +default = ["fallback"] +std = [] +fallback = [] + +[build-dependencies] +autocfg = "1" @@ -0,0 +1 @@ +LICENSE-APACHE
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IN NO EVENT +SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR +IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +DEALINGS IN THE SOFTWARE. diff --git a/METADATA b/METADATA new file mode 100644 index 0000000..ada5837 --- /dev/null +++ b/METADATA @@ -0,0 +1,20 @@ +name: "atomic" +description: "Generic Atomic<T> wrapper type" +third_party { + url { + type: HOMEPAGE + value: "https://crates.io/crates/atomic" + } + url { + type: ARCHIVE + value: "https://static.crates.io/crates/atomic/atomic-0.5.1.crate" + } + version: "0.5.1" + # Dual-licensed, using the least restrictive per go/thirdpartylicenses#same. + license_type: NOTICE + last_upgrade_date { + year: 2023 + month: 1 + day: 17 + } +} diff --git a/MODULE_LICENSE_APACHE2 b/MODULE_LICENSE_APACHE2 new file mode 100644 index 0000000..e69de29 --- /dev/null +++ b/MODULE_LICENSE_APACHE2 @@ -0,0 +1 @@ +include platform/prebuilts/rust:master:/OWNERS diff --git a/README.md b/README.md new file mode 100644 index 0000000..ea2c0cb --- /dev/null +++ b/README.md @@ -0,0 +1,42 @@ +Generic `Atomic<T>` for Rust +============================ + +[![Build Status](https://travis-ci.org/Amanieu/atomic-rs.svg?branch=master)](https://travis-ci.org/Amanieu/atomic-rs) [![Crates.io](https://img.shields.io/crates/v/atomic.svg)](https://crates.io/crates/atomic) + +A Rust library which provides a generic `Atomic<T>` type for all `T: Copy` types, unlike the standard library which only provides a few fixed atomic types (`AtomicBool`, `AtomicIsize`, `AtomicUsize`, `AtomicPtr`). + +This library will use native atomic instructions if possible, and will otherwise fall back to a lock-based mechanism. You can use the `Atomic::<T>::is_lock_free()` function to check whether native atomic operations are supported for a given type. Note that a type must have a power-of-2 size and alignment in order to be used by native atomic instructions. + +This crate uses `#![no_std]` and only depends on libcore. + +[Documentation](https://amanieu.github.io/atomic-rs/atomic/index.html) + +## Usage + +Add this to your `Cargo.toml`: + +```toml +[dependencies] +atomic = "0.5" +``` + +and this to your crate root: + +```rust +extern crate atomic; +``` + +## License + +Licensed under either of + + * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) + * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) + +at your option. + +### Contribution + +Unless you explicitly state otherwise, any contribution intentionally submitted +for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any +additional terms or conditions. diff --git a/build.rs b/build.rs new file mode 100644 index 0000000..4cf4274 --- /dev/null +++ b/build.rs @@ -0,0 +1,16 @@ +fn main() { + let ac = autocfg::new(); + + for root in &["core", "std"] { + for size in &[8, 16, 32, 64, 128] { + ac.emit_expression_cfg( + &format!("{}::sync::atomic::AtomicU{}::compare_exchange", root, size), + &format!("has_atomic_u{}", size), + ); + ac.emit_expression_cfg( + &format!("{}::sync::atomic::AtomicI{}::compare_exchange", root, size), + &format!("has_atomic_i{}", size), + ); + } + } +} diff --git a/cargo2android.json b/cargo2android.json new file mode 100644 index 0000000..5871db7 --- /dev/null +++ b/cargo2android.json @@ -0,0 +1,10 @@ +{ + "apex-available": [ + "//apex_available:platform", + "com.android.virt" + ], + "dependencies": true, + "device": true, + "features": "fallback,std", + "run": true +} diff --git a/src/fallback.rs b/src/fallback.rs new file mode 100644 index 0000000..8b7e861 --- /dev/null +++ b/src/fallback.rs @@ -0,0 +1,196 @@ +// Copyright 2016 Amanieu d'Antras +// +// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or +// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or +// http://opensource.org/licenses/MIT>, at your option. This file may not be +// copied, modified, or distributed except according to those terms. + +use core::cmp; +use core::mem; +use core::num::Wrapping; +use core::ops; +use core::ptr; +use core::slice; +use core::sync::atomic::{self, AtomicUsize, Ordering}; + +// We use an AtomicUsize instead of an AtomicBool because it performs better +// on architectures that don't have byte-sized atomics. +// +// We give each spinlock its own cache line to avoid false sharing. +#[repr(align(64))] +struct SpinLock(AtomicUsize); + +impl SpinLock { + fn lock(&self) { + while self + .0 + .compare_exchange_weak(0, 1, Ordering::Acquire, Ordering::Relaxed) + .is_err() + { + while self.0.load(Ordering::Relaxed) != 0 { + atomic::spin_loop_hint(); + } + } + } + + fn unlock(&self) { + self.0.store(0, Ordering::Release); + } +} + +// A big array of spinlocks which we use to guard atomic accesses. A spinlock is +// chosen based on a hash of the address of the atomic object, which helps to +// reduce contention compared to a single global lock. +macro_rules! array { + (@accum (0, $($_es:expr),*) -> ($($body:tt)*)) + => {array!(@as_expr [$($body)*])}; + (@accum (1, $($es:expr),*) -> ($($body:tt)*)) + => {array!(@accum (0, $($es),*) -> ($($body)* $($es,)*))}; + (@accum (2, $($es:expr),*) -> ($($body:tt)*)) + => {array!(@accum (0, $($es),*) -> ($($body)* $($es,)* $($es,)*))}; + (@accum (4, $($es:expr),*) -> ($($body:tt)*)) + => {array!(@accum (2, $($es,)* $($es),*) -> ($($body)*))}; + (@accum (8, $($es:expr),*) -> ($($body:tt)*)) + => {array!(@accum (4, $($es,)* $($es),*) -> ($($body)*))}; + (@accum (16, $($es:expr),*) -> ($($body:tt)*)) + => {array!(@accum (8, $($es,)* $($es),*) -> ($($body)*))}; + (@accum (32, $($es:expr),*) -> ($($body:tt)*)) + => {array!(@accum (16, $($es,)* $($es),*) -> ($($body)*))}; + (@accum (64, $($es:expr),*) -> ($($body:tt)*)) + => {array!(@accum (32, $($es,)* $($es),*) -> ($($body)*))}; + + (@as_expr $e:expr) => {$e}; + + [$e:expr; $n:tt] => { array!(@accum ($n, $e) -> ()) }; +} +static SPINLOCKS: [SpinLock; 64] = array![SpinLock(AtomicUsize::new(0)); 64]; + +// Spinlock pointer hashing function from compiler-rt +#[inline] +fn lock_for_addr(addr: usize) -> &'static SpinLock { + // Disregard the lowest 4 bits. We want all values that may be part of the + // same memory operation to hash to the same value and therefore use the same + // lock. + let mut hash = addr >> 4; + // Use the next bits as the basis for the hash + let low = hash & (SPINLOCKS.len() - 1); + // Now use the high(er) set of bits to perturb the hash, so that we don't + // get collisions from atomic fields in a single object + hash >>= 16; + hash ^= low; + // Return a pointer to the lock to use + &SPINLOCKS[hash & (SPINLOCKS.len() - 1)] +} + +#[inline] +fn lock(addr: usize) -> LockGuard { + let lock = lock_for_addr(addr); + lock.lock(); + LockGuard(lock) +} + +struct LockGuard(&'static SpinLock); +impl Drop for LockGuard { + #[inline] + fn drop(&mut self) { + self.0.unlock(); + } +} + +#[inline] +pub unsafe fn atomic_load<T>(dst: *mut T) -> T { + let _l = lock(dst as usize); + ptr::read(dst) +} + +#[inline] +pub unsafe fn atomic_store<T>(dst: *mut T, val: T) { + let _l = lock(dst as usize); + ptr::write(dst, val); +} + +#[inline] +pub unsafe fn atomic_swap<T>(dst: *mut T, val: T) -> T { + let _l = lock(dst as usize); + ptr::replace(dst, val) +} + +#[inline] +pub unsafe fn atomic_compare_exchange<T>(dst: *mut T, current: T, new: T) -> Result<T, T> { + let _l = lock(dst as usize); + let result = ptr::read(dst); + // compare_exchange compares with memcmp instead of Eq + let a = slice::from_raw_parts(&result as *const _ as *const u8, mem::size_of_val(&result)); + let b = slice::from_raw_parts( + ¤t as *const _ as *const u8, + mem::size_of_val(¤t), + ); + if a == b { + ptr::write(dst, new); + Ok(result) + } else { + Err(result) + } +} + +#[inline] +pub unsafe fn atomic_add<T: Copy>(dst: *mut T, val: T) -> T +where + Wrapping<T>: ops::Add<Output = Wrapping<T>>, +{ + let _l = lock(dst as usize); + let result = ptr::read(dst); + ptr::write(dst, (Wrapping(result) + Wrapping(val)).0); + result +} + +#[inline] +pub unsafe fn atomic_sub<T: Copy>(dst: *mut T, val: T) -> T +where + Wrapping<T>: ops::Sub<Output = Wrapping<T>>, +{ + let _l = lock(dst as usize); + let result = ptr::read(dst); + ptr::write(dst, (Wrapping(result) - Wrapping(val)).0); + result +} + +#[inline] +pub unsafe fn atomic_and<T: Copy + ops::BitAnd<Output = T>>(dst: *mut T, val: T) -> T { + let _l = lock(dst as usize); + let result = ptr::read(dst); + ptr::write(dst, result & val); + result +} + +#[inline] +pub unsafe fn atomic_or<T: Copy + ops::BitOr<Output = T>>(dst: *mut T, val: T) -> T { + let _l = lock(dst as usize); + let result = ptr::read(dst); + ptr::write(dst, result | val); + result +} + +#[inline] +pub unsafe fn atomic_xor<T: Copy + ops::BitXor<Output = T>>(dst: *mut T, val: T) -> T { + let _l = lock(dst as usize); + let result = ptr::read(dst); + ptr::write(dst, result ^ val); + result +} + +#[inline] +pub unsafe fn atomic_min<T: Copy + cmp::Ord>(dst: *mut T, val: T) -> T { + let _l = lock(dst as usize); + let result = ptr::read(dst); + ptr::write(dst, cmp::min(result, val)); + result +} + +#[inline] +pub unsafe fn atomic_max<T: Copy + cmp::Ord>(dst: *mut T, val: T) -> T { + let _l = lock(dst as usize); + let result = ptr::read(dst); + ptr::write(dst, cmp::max(result, val)); + result +} diff --git a/src/lib.rs b/src/lib.rs new file mode 100644 index 0000000..09ad879 --- /dev/null +++ b/src/lib.rs @@ -0,0 +1,711 @@ +// Copyright 2016 Amanieu d'Antras +// +// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or +// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or +// http://opensource.org/licenses/MIT>, at your option. This file may not be +// copied, modified, or distributed except according to those terms. + +//! Generic `Atomic<T>` wrapper type +//! +//! Atomic types provide primitive shared-memory communication between +//! threads, and are the building blocks of other concurrent types. +//! +//! This library defines a generic atomic wrapper type `Atomic<T>` for all +//! `T: Copy` types. +//! 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][1]. +//! +//! [1]: http://llvm.org/docs/LangRef.html#memory-model-for-concurrent-operations +//! +//! Atomic variables are safe to share between threads (they implement `Sync`) +//! but they do not themselves provide the mechanism for sharing. 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 `const fn` constructors. Atomic statics are often used for lazy global +//! initialization. + +#![warn(missing_docs)] +#![warn(rust_2018_idioms)] +#![no_std] + +#[cfg(any(test, feature = "std"))] +#[macro_use] +extern crate std; + +// Re-export some useful definitions from libcore +pub use core::sync::atomic::{fence, Ordering}; + +use core::cell::UnsafeCell; +use core::fmt; + +#[cfg(feature = "std")] +use std::panic::RefUnwindSafe; + +#[cfg(feature = "fallback")] +mod fallback; +mod ops; + +/// A generic atomic wrapper type which allows an object to be safely shared +/// between threads. +#[repr(transparent)] +pub struct Atomic<T> { + v: UnsafeCell<T>, +} + +// Atomic<T> is only Sync if T is Send +unsafe impl<T: Copy + Send> Sync for Atomic<T> {} + +// Given that atomicity is guaranteed, Atomic<T> is RefUnwindSafe if T is +// +// This is trivially correct for native lock-free atomic types. For those whose +// atomicity is emulated using a spinlock, it is still correct because the +// `Atomic` API does not allow doing any panic-inducing operation after writing +// to the target object. +#[cfg(feature = "std")] +impl<T: Copy + RefUnwindSafe> RefUnwindSafe for Atomic<T> {} + +impl<T: Copy + Default> Default for Atomic<T> { + #[inline] + fn default() -> Self { + Self::new(Default::default()) + } +} + +impl<T: Copy + fmt::Debug> fmt::Debug for Atomic<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("Atomic") + .field(&self.load(Ordering::SeqCst)) + .finish() + } +} + +impl<T> Atomic<T> { + /// Creates a new `Atomic`. + #[inline] + pub const fn new(v: T) -> Atomic<T> { + Atomic { + v: UnsafeCell::new(v), + } + } + + /// Checks if `Atomic` objects of this type are lock-free. + /// + /// If an `Atomic` is not lock-free then it may be implemented using locks + /// internally, which makes it unsuitable for some situations (such as + /// communicating with a signal handler). + #[inline] + pub const fn is_lock_free() -> bool { + ops::atomic_is_lock_free::<T>() + } +} + +impl<T: Copy> Atomic<T> { + /// Returns a mutable reference to the underlying type. + /// + /// This is safe because the mutable reference guarantees that no other threads are + /// concurrently accessing the atomic data. + #[inline] + pub fn get_mut(&mut self) -> &mut T { + unsafe { &mut *self.v.get() } + } + + /// 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. + #[inline] + pub fn into_inner(self) -> T { + self.v.into_inner() + } + + /// Loads a value from the `Atomic`. + /// + /// `load` takes an `Ordering` argument which describes the memory ordering + /// of this operation. + /// + /// # Panics + /// + /// Panics if `order` is `Release` or `AcqRel`. + #[inline] + pub fn load(&self, order: Ordering) -> T { + unsafe { ops::atomic_load(self.v.get(), order) } + } + + /// Stores a value into the `Atomic`. + /// + /// `store` takes an `Ordering` argument which describes the memory ordering + /// of this operation. + /// + /// # Panics + /// + /// Panics if `order` is `Acquire` or `AcqRel`. + #[inline] + pub fn store(&self, val: T, order: Ordering) { + unsafe { + ops::atomic_store(self.v.get(), val, order); + } + } + + /// Stores a value into the `Atomic`, returning the old value. + /// + /// `swap` takes an `Ordering` argument which describes the memory ordering + /// of this operation. + #[inline] + pub fn swap(&self, val: T, order: Ordering) -> T { + unsafe { ops::atomic_swap(self.v.get(), val, order) } + } + + /// Stores a value into the `Atomic` 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. + #[inline] + pub fn compare_exchange( + &self, + current: T, + new: T, + success: Ordering, + failure: Ordering, + ) -> Result<T, T> { + unsafe { ops::atomic_compare_exchange(self.v.get(), current, new, success, failure) } + } + + /// Stores a value into the `Atomic` 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` 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. + /// success ordering. + #[inline] + pub fn compare_exchange_weak( + &self, + current: T, + new: T, + success: Ordering, + failure: Ordering, + ) -> Result<T, T> { + unsafe { ops::atomic_compare_exchange_weak(self.v.get(), current, new, success, failure) } + } + + /// 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 + /// [`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`] + /// and must be equivalent to or weaker than the success ordering. + /// + /// [`compare_exchange`]: #method.compare_exchange + /// [`Ordering`]: enum.Ordering.html + /// [`Relaxed`]: enum.Ordering.html#variant.Relaxed + /// [`Release`]: enum.Ordering.html#variant.Release + /// [`Acquire`]: enum.Ordering.html#variant.Acquire + /// [`SeqCst`]: enum.Ordering.html#variant.SeqCst + /// + /// # Examples + /// + /// ```rust + /// use atomic::{Atomic, Ordering}; + /// + /// let x = Atomic::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); + /// ``` + #[inline] + pub fn fetch_update<F>( + &self, + set_order: Ordering, + fetch_order: Ordering, + mut f: F, + ) -> Result<T, T> + where + F: FnMut(T) -> Option<T>, + { + let mut prev = self.load(fetch_order); + while let Some(next) = f(prev) { + match self.compare_exchange_weak(prev, next, set_order, fetch_order) { + x @ Ok(_) => return x, + Err(next_prev) => prev = next_prev, + } + } + Err(prev) + } +} + +impl Atomic<bool> { + /// Logical "and" with a boolean value. + /// + /// Performs a logical "and" operation on the current value and the argument + /// `val`, and sets the new value to the result. + /// + /// Returns the previous value. + #[inline] + pub fn fetch_and(&self, val: bool, order: Ordering) -> bool { + unsafe { ops::atomic_and(self.v.get(), val, order) } + } + + /// Logical "or" with a boolean value. + /// + /// Performs a logical "or" operation on the current value and the argument + /// `val`, and sets the new value to the result. + /// + /// Returns the previous value. + #[inline] + pub fn fetch_or(&self, val: bool, order: Ordering) -> bool { + unsafe { ops::atomic_or(self.v.get(), val, order) } + } + + /// Logical "xor" with a boolean value. + /// + /// Performs a logical "xor" operation on the current value and the argument + /// `val`, and sets the new value to the result. + /// + /// Returns the previous value. + #[inline] + pub fn fetch_xor(&self, val: bool, order: Ordering) -> bool { + unsafe { ops::atomic_xor(self.v.get(), val, order) } + } +} + +macro_rules! atomic_ops_common { + ($($t:ty)*) => ($( + impl Atomic<$t> { + /// Add to the current value, returning the previous value. + #[inline] + pub fn fetch_add(&self, val: $t, order: Ordering) -> $t { + unsafe { ops::atomic_add(self.v.get(), val, order) } + } + + /// Subtract from the current value, returning the previous value. + #[inline] + pub fn fetch_sub(&self, val: $t, order: Ordering) -> $t { + unsafe { ops::atomic_sub(self.v.get(), val, order) } + } + + /// Bitwise and with the current value, returning the previous value. + #[inline] + pub fn fetch_and(&self, val: $t, order: Ordering) -> $t { + unsafe { ops::atomic_and(self.v.get(), val, order) } + } + + /// Bitwise or with the current value, returning the previous value. + #[inline] + pub fn fetch_or(&self, val: $t, order: Ordering) -> $t { + unsafe { ops::atomic_or(self.v.get(), val, order) } + } + + /// Bitwise xor with the current value, returning the previous value. + #[inline] + pub fn fetch_xor(&self, val: $t, order: Ordering) -> $t { + unsafe { ops::atomic_xor(self.v.get(), val, order) } + } + } + )*); +} +macro_rules! atomic_ops_signed { + ($($t:ty)*) => ( + atomic_ops_common!{ $($t)* } + $( + impl Atomic<$t> { + /// Minimum with the current value. + #[inline] + pub fn fetch_min(&self, val: $t, order: Ordering) -> $t { + unsafe { ops::atomic_min(self.v.get(), val, order) } + } + + /// Maximum with the current value. + #[inline] + pub fn fetch_max(&self, val: $t, order: Ordering) -> $t { + unsafe { ops::atomic_max(self.v.get(), val, order) } + } + } + )* + ); +} +macro_rules! atomic_ops_unsigned { + ($($t:ty)*) => ( + atomic_ops_common!{ $($t)* } + $( + impl Atomic<$t> { + /// Minimum with the current value. + #[inline] + pub fn fetch_min(&self, val: $t, order: Ordering) -> $t { + unsafe { ops::atomic_umin(self.v.get(), val, order) } + } + + /// Maximum with the current value. + #[inline] + pub fn fetch_max(&self, val: $t, order: Ordering) -> $t { + unsafe { ops::atomic_umax(self.v.get(), val, order) } + } + } + )* + ); +} +atomic_ops_signed! { i8 i16 i32 i64 isize i128 } +atomic_ops_unsigned! { u8 u16 u32 u64 usize u128 } + +#[cfg(test)] +mod tests { + use super::{Atomic, Ordering::*}; + use core::mem; + + #[derive(Copy, Clone, Eq, PartialEq, Debug, Default)] + struct Foo(u8, u8); + #[derive(Copy, Clone, Eq, PartialEq, Debug, Default)] + struct Bar(u64, u64); + #[derive(Copy, Clone, Eq, PartialEq, Debug, Default)] + struct Quux(u32); + + #[test] + fn atomic_bool() { + let a = Atomic::new(false); + assert_eq!(Atomic::<bool>::is_lock_free(), cfg!(has_atomic_u8),); + assert_eq!(format!("{:?}", a), "Atomic(false)"); + assert_eq!(a.load(SeqCst), false); + a.store(true, SeqCst); + assert_eq!(a.swap(false, SeqCst), true); + assert_eq!(a.compare_exchange(true, false, SeqCst, SeqCst), Err(false)); + assert_eq!(a.compare_exchange(false, true, SeqCst, SeqCst), Ok(false)); + assert_eq!(a.fetch_and(false, SeqCst), true); + assert_eq!(a.fetch_or(true, SeqCst), false); + assert_eq!(a.fetch_xor(false, SeqCst), true); + assert_eq!(a.load(SeqCst), true); + } + + #[test] + fn atomic_i8() { + let a = Atomic::new(0i8); + assert_eq!(Atomic::<i8>::is_lock_free(), cfg!(has_atomic_u8)); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + // Make sure overflows are handled correctly + assert_eq!(a.fetch_sub(-56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), -74); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(-25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_i16() { + let a = Atomic::new(0i16); + assert_eq!(Atomic::<i16>::is_lock_free(), cfg!(has_atomic_u16)); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(-56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 182); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(-25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_i32() { + let a = Atomic::new(0i32); + assert_eq!(Atomic::<i32>::is_lock_free(), cfg!(has_atomic_u32)); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(-56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 182); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(-25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_i64() { + let a = Atomic::new(0i64); + assert_eq!( + Atomic::<i64>::is_lock_free(), + cfg!(has_atomic_u64) && mem::align_of::<i64>() == 8 + ); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(-56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 182); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(-25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_i128() { + let a = Atomic::new(0i128); + assert_eq!(Atomic::<i128>::is_lock_free(), cfg!(has_atomic_u128)); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(-56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 182); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(-25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_isize() { + let a = Atomic::new(0isize); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(-56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 182); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(-25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_u8() { + let a = Atomic::new(0u8); + assert_eq!(Atomic::<u8>::is_lock_free(), cfg!(has_atomic_u8)); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 70); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_u16() { + let a = Atomic::new(0u16); + assert_eq!(Atomic::<u16>::is_lock_free(), cfg!(has_atomic_u16)); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 70); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_u32() { + let a = Atomic::new(0u32); + assert_eq!(Atomic::<u32>::is_lock_free(), cfg!(has_atomic_u32)); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 70); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_u64() { + let a = Atomic::new(0u64); + assert_eq!( + Atomic::<u64>::is_lock_free(), + cfg!(has_atomic_u64) && mem::align_of::<u64>() == 8 + ); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 70); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_u128() { + let a = Atomic::new(0u128); + assert_eq!(Atomic::<u128>::is_lock_free(), cfg!(has_atomic_u128)); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 70); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_usize() { + let a = Atomic::new(0usize); + assert_eq!(format!("{:?}", a), "Atomic(0)"); + assert_eq!(a.load(SeqCst), 0); + a.store(1, SeqCst); + assert_eq!(a.swap(2, SeqCst), 1); + assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2)); + assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2)); + assert_eq!(a.fetch_add(123, SeqCst), 3); + assert_eq!(a.fetch_sub(56, SeqCst), 126); + assert_eq!(a.fetch_and(7, SeqCst), 70); + assert_eq!(a.fetch_or(64, SeqCst), 6); + assert_eq!(a.fetch_xor(1, SeqCst), 70); + assert_eq!(a.fetch_min(30, SeqCst), 71); + assert_eq!(a.fetch_max(25, SeqCst), 30); + assert_eq!(a.load(SeqCst), 30); + } + + #[test] + fn atomic_foo() { + let a = Atomic::default(); + assert_eq!(Atomic::<Foo>::is_lock_free(), false); + assert_eq!(format!("{:?}", a), "Atomic(Foo(0, 0))"); + assert_eq!(a.load(SeqCst), Foo(0, 0)); + a.store(Foo(1, 1), SeqCst); + assert_eq!(a.swap(Foo(2, 2), SeqCst), Foo(1, 1)); + assert_eq!( + a.compare_exchange(Foo(5, 5), Foo(45, 45), SeqCst, SeqCst), + Err(Foo(2, 2)) + ); + assert_eq!( + a.compare_exchange(Foo(2, 2), Foo(3, 3), SeqCst, SeqCst), + Ok(Foo(2, 2)) + ); + assert_eq!(a.load(SeqCst), Foo(3, 3)); + } + + #[test] + fn atomic_bar() { + let a = Atomic::default(); + assert_eq!(Atomic::<Bar>::is_lock_free(), false); + assert_eq!(format!("{:?}", a), "Atomic(Bar(0, 0))"); + assert_eq!(a.load(SeqCst), Bar(0, 0)); + a.store(Bar(1, 1), SeqCst); + assert_eq!(a.swap(Bar(2, 2), SeqCst), Bar(1, 1)); + assert_eq!( + a.compare_exchange(Bar(5, 5), Bar(45, 45), SeqCst, SeqCst), + Err(Bar(2, 2)) + ); + assert_eq!( + a.compare_exchange(Bar(2, 2), Bar(3, 3), SeqCst, SeqCst), + Ok(Bar(2, 2)) + ); + assert_eq!(a.load(SeqCst), Bar(3, 3)); + } + + #[test] + fn atomic_quxx() { + let a = Atomic::default(); + assert_eq!(Atomic::<Quux>::is_lock_free(), cfg!(has_atomic_u32)); + assert_eq!(format!("{:?}", a), "Atomic(Quux(0))"); + assert_eq!(a.load(SeqCst), Quux(0)); + a.store(Quux(1), SeqCst); + assert_eq!(a.swap(Quux(2), SeqCst), Quux(1)); + assert_eq!( + a.compare_exchange(Quux(5), Quux(45), SeqCst, SeqCst), + Err(Quux(2)) + ); + assert_eq!( + a.compare_exchange(Quux(2), Quux(3), SeqCst, SeqCst), + Ok(Quux(2)) + ); + assert_eq!(a.load(SeqCst), Quux(3)); + } +} diff --git a/src/ops.rs b/src/ops.rs new file mode 100644 index 0000000..808335c --- /dev/null +++ b/src/ops.rs @@ -0,0 +1,296 @@ +// Copyright 2016 Amanieu d'Antras +// +// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or +// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or +// http://opensource.org/licenses/MIT>, at your option. This file may not be +// copied, modified, or distributed except according to those terms. + +#[cfg(feature = "fallback")] +use crate::fallback; +use core::cmp; +use core::mem; +use core::num::Wrapping; +use core::ops; +use core::sync::atomic::Ordering; + +macro_rules! match_atomic { + ($type:ident, $atomic:ident, $impl:expr, $fallback_impl:expr) => { + match mem::size_of::<$type>() { + #[cfg(has_atomic_u8)] + 1 if mem::align_of::<$type>() >= 1 => { + type $atomic = core::sync::atomic::AtomicU8; + + $impl + } + #[cfg(has_atomic_u16)] + 2 if mem::align_of::<$type>() >= 2 => { + type $atomic = core::sync::atomic::AtomicU16; + + $impl + } + #[cfg(has_atomic_u32)] + 4 if mem::align_of::<$type>() >= 4 => { + type $atomic = core::sync::atomic::AtomicU32; + + $impl + } + #[cfg(has_atomic_u64)] + 8 if mem::align_of::<$type>() >= 8 => { + type $atomic = core::sync::atomic::AtomicU64; + + $impl + } + #[cfg(has_atomic_u128)] + 16 if mem::align_of::<$type>() >= 16 => { + type $atomic = core::sync::atomic::AtomicU128; + + $impl + } + #[cfg(feature = "fallback")] + _ => $fallback_impl, + #[cfg(not(feature = "fallback"))] + _ => panic!("Atomic operations for type `{}` are not available as the `fallback` feature of the `atomic` crate is disabled.", core::any::type_name::<$type>()), + } + }; +} + +macro_rules! match_signed_atomic { + ($type:ident, $atomic:ident, $impl:expr, $fallback_impl:expr) => { + match mem::size_of::<$type>() { + #[cfg(has_atomic_i8)] + 1 if mem::align_of::<$type>() >= 1 => { + type $atomic = core::sync::atomic::AtomicI8; + + $impl + } + #[cfg(has_atomic_i16)] + 2 if mem::align_of::<$type>() >= 2 => { + type $atomic = core::sync::atomic::AtomicI16; + + $impl + } + #[cfg(has_atomic_i32)] + 4 if mem::align_of::<$type>() >= 4 => { + type $atomic = core::sync::atomic::AtomicI32; + + $impl + } + #[cfg(has_atomic_i64)] + 8 if mem::align_of::<$type>() >= 8 => { + type $atomic = core::sync::atomic::AtomicI64; + + $impl + } + #[cfg(has_atomic_u128)] + 16 if mem::align_of::<$type>() >= 16 => { + type $atomic = core::sync::atomic::AtomicI128; + + $impl + } + #[cfg(feature = "fallback")] + _ => $fallback_impl, + #[cfg(not(feature = "fallback"))] + _ => panic!("Atomic operations for type `{}` are not available as the `fallback` feature of the `atomic` crate is disabled.", core::any::type_name::<$type>()), + } + }; +} + +#[inline] +pub const fn atomic_is_lock_free<T>() -> bool { + let size = mem::size_of::<T>(); + let align = mem::align_of::<T>(); + + (cfg!(has_atomic_u8) & (size == 1) & (align >= 1)) + | (cfg!(has_atomic_u16) & (size == 2) & (align >= 2)) + | (cfg!(has_atomic_u32) & (size == 4) & (align >= 4)) + | (cfg!(has_atomic_u64) & (size == 8) & (align >= 8)) + | (cfg!(has_atomic_u128) & (size == 16) & (align >= 16)) +} + +#[inline] +pub unsafe fn atomic_load<T>(dst: *mut T, order: Ordering) -> T { + match_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).load(order)), + fallback::atomic_load(dst) + ) +} + +#[inline] +pub unsafe fn atomic_store<T>(dst: *mut T, val: T, order: Ordering) { + match_atomic!( + T, + A, + (*(dst as *const A)).store(mem::transmute_copy(&val), order), + fallback::atomic_store(dst, val) + ) +} + +#[inline] +pub unsafe fn atomic_swap<T>(dst: *mut T, val: T, order: Ordering) -> T { + match_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).swap(mem::transmute_copy(&val), order)), + fallback::atomic_swap(dst, val) + ) +} + +#[inline] +unsafe fn map_result<T, U>(r: Result<T, T>) -> Result<U, U> { + match r { + Ok(x) => Ok(mem::transmute_copy(&x)), + Err(x) => Err(mem::transmute_copy(&x)), + } +} + +#[inline] +pub unsafe fn atomic_compare_exchange<T>( + dst: *mut T, + current: T, + new: T, + success: Ordering, + failure: Ordering, +) -> Result<T, T> { + match_atomic!( + T, + A, + map_result((*(dst as *const A)).compare_exchange( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )), + fallback::atomic_compare_exchange(dst, current, new) + ) +} + +#[inline] +pub unsafe fn atomic_compare_exchange_weak<T>( + dst: *mut T, + current: T, + new: T, + success: Ordering, + failure: Ordering, +) -> Result<T, T> { + match_atomic!( + T, + A, + map_result((*(dst as *const A)).compare_exchange_weak( + mem::transmute_copy(¤t), + mem::transmute_copy(&new), + success, + failure, + )), + fallback::atomic_compare_exchange(dst, current, new) + ) +} + +#[inline] +pub unsafe fn atomic_add<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T +where + Wrapping<T>: ops::Add<Output = Wrapping<T>>, +{ + match_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).fetch_add(mem::transmute_copy(&val), order),), + fallback::atomic_add(dst, val) + ) +} + +#[inline] +pub unsafe fn atomic_sub<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T +where + Wrapping<T>: ops::Sub<Output = Wrapping<T>>, +{ + match_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).fetch_sub(mem::transmute_copy(&val), order),), + fallback::atomic_sub(dst, val) + ) +} + +#[inline] +pub unsafe fn atomic_and<T: Copy + ops::BitAnd<Output = T>>( + dst: *mut T, + val: T, + order: Ordering, +) -> T { + match_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).fetch_and(mem::transmute_copy(&val), order),), + fallback::atomic_and(dst, val) + ) +} + +#[inline] +pub unsafe fn atomic_or<T: Copy + ops::BitOr<Output = T>>( + dst: *mut T, + val: T, + order: Ordering, +) -> T { + match_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).fetch_or(mem::transmute_copy(&val), order),), + fallback::atomic_or(dst, val) + ) +} + +#[inline] +pub unsafe fn atomic_xor<T: Copy + ops::BitXor<Output = T>>( + dst: *mut T, + val: T, + order: Ordering, +) -> T { + match_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).fetch_xor(mem::transmute_copy(&val), order),), + fallback::atomic_xor(dst, val) + ) +} + +#[inline] +pub unsafe fn atomic_min<T: Copy + cmp::Ord>(dst: *mut T, val: T, order: Ordering) -> T { + match_signed_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).fetch_min(mem::transmute_copy(&val), order),), + fallback::atomic_min(dst, val) + ) +} + +#[inline] +pub unsafe fn atomic_max<T: Copy + cmp::Ord>(dst: *mut T, val: T, order: Ordering) -> T { + match_signed_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).fetch_max(mem::transmute_copy(&val), order),), + fallback::atomic_max(dst, val) + ) +} + +#[inline] +pub unsafe fn atomic_umin<T: Copy + cmp::Ord>(dst: *mut T, val: T, order: Ordering) -> T { + match_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).fetch_min(mem::transmute_copy(&val), order),), + fallback::atomic_min(dst, val) + ) +} + +#[inline] +pub unsafe fn atomic_umax<T: Copy + cmp::Ord>(dst: *mut T, val: T, order: Ordering) -> T { + match_atomic!( + T, + A, + mem::transmute_copy(&(*(dst as *const A)).fetch_max(mem::transmute_copy(&val), order),), + fallback::atomic_max(dst, val) + ) +} |