[ { "path": ".github/workflows/release-plz.yml", "content": "name: Release-plz\n\non:\n push:\n branches:\n - master\n\njobs:\n release-plz-release:\n name: Release-plz release\n runs-on: ubuntu-latest\n if: ${{ github.repository_owner == 'Amanieu' }}\n permissions:\n contents: write\n steps:\n - name: Checkout repository\n uses: actions/checkout@v4\n with:\n fetch-depth: 0\n - name: Install Rust toolchain\n uses: dtolnay/rust-toolchain@stable\n - name: Run release-plz\n uses: release-plz/action@v0.5\n with:\n command: release\n env:\n GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}\n CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}\n\n release-plz-pr:\n name: Release-plz PR\n runs-on: ubuntu-latest\n if: ${{ github.repository_owner == 'Amanieu' }}\n permissions:\n pull-requests: write\n contents: write\n concurrency:\n group: release-plz-${{ github.ref }}\n cancel-in-progress: false\n steps:\n - name: Checkout repository\n uses: actions/checkout@v4\n with:\n fetch-depth: 0\n - name: Install Rust toolchain\n uses: dtolnay/rust-toolchain@stable\n - name: Run release-plz\n uses: release-plz/action@v0.5\n with:\n command: release-pr\n env:\n GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}\n CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}\n" }, { "path": ".gitignore", "content": "target\nCargo.lock\n" }, { "path": ".travis.yml", "content": "language: rust\nsudo: false\n\nrust:\n- nightly\n- beta\n- stable\n- 1.45.0\n\nscript:\n- cargo build\n- cargo test\n- cargo doc\n- if [ $TRAVIS_RUST_VERSION = nightly ]; then rustup target add aarch64-unknown-none; fi\n- if [ $TRAVIS_RUST_VERSION = nightly ]; then RUSTFLAGS=\"-Zcrate-attr=feature(integer_atomics)\" cargo check --target=aarch64-unknown-none; fi\n\nnotifications:\n email: false\n" }, { "path": "CHANGELOG.md", "content": "# Changelog\n\nAll notable changes to this project will be documented in this file.\n\nThe format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),\nand this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).\n\n## [Unreleased]\n\n## [0.6.1](https://github.com/Amanieu/atomic-rs/compare/v0.6.0...v0.6.1) - 2025-06-19\n\n### Other\n\n- Implement (de)serialization with `serde`.\n" }, { "path": "Cargo.toml", "content": "[package]\nname = \"atomic\"\nversion = \"0.6.1\"\nedition = \"2018\"\nauthors = [\"Amanieu d'Antras \"]\ndescription = \"Generic Atomic wrapper type\"\nlicense = \"Apache-2.0/MIT\"\nrepository = \"https://github.com/Amanieu/atomic-rs\"\nreadme = \"README.md\"\nkeywords = [\"atomic\", \"no_std\"]\n\n[features]\ndefault = [\"fallback\"]\nstd = []\nfallback = []\nnightly = []\nserde = [\"dep:serde\"]\n\n[dependencies]\nbytemuck = \"1.13.1\"\nserde = { version = \"1.0.219\", default-features = false, optional = true }\n\n[dev-dependencies]\nbytemuck = { version = \"1.13.1\", features = [\"derive\"] }\nserde = { version = \"1.0.219\", default-features = false, features = [\"derive\"] }\nserde_json = { version = \"1.0.140\" }\n" }, { "path": "LICENSE-APACHE", "content": " Apache License\n Version 2.0, January 2004\n http://www.apache.org/licenses/\n\nTERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION\n\n1. 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We also recommend that a\n file or class name and description of purpose be included on the\n same \"printed page\" as the copyright notice for easier\n identification within third-party archives.\n\nCopyright [yyyy] [name of copyright owner]\n\nLicensed under the Apache License, Version 2.0 (the \"License\");\nyou may not use this file except in compliance with the License.\nYou may obtain a copy of the License at\n\n\thttp://www.apache.org/licenses/LICENSE-2.0\n\nUnless required by applicable law or agreed to in writing, software\ndistributed under the License is distributed on an \"AS IS\" BASIS,\nWITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\nSee the License for the specific language governing permissions and\nlimitations under the License.\n" }, { "path": "LICENSE-MIT", "content": "Copyright (c) 2016 The Rust Project Developers\n\nPermission is hereby granted, free of charge, to any\nperson obtaining a copy of this software and associated\ndocumentation files (the \"Software\"), to deal in the\nSoftware without restriction, including without\nlimitation the rights to use, copy, modify, merge,\npublish, distribute, sublicense, and/or sell copies of\nthe Software, and to permit persons to whom the Software\nis furnished to do so, subject to the following\nconditions:\n\nThe above copyright notice and this permission notice\nshall be included in all copies or substantial portions\nof the Software.\n\nTHE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF\nANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED\nTO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A\nPARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT\nSHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY\nCLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION\nOF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR\nIN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER\nDEALINGS IN THE SOFTWARE.\n" }, { "path": "README.md", "content": "Generic `Atomic` for Rust\n============================\n\n[![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)\n\nA Rust library which provides a generic `Atomic` type for all `T: NoUninit` types, unlike the standard library which only provides a few fixed atomic types (`AtomicBool`, `AtomicIsize`, `AtomicUsize`, `AtomicPtr`). The `NoUninit` bound is from the [bytemuck] crate, and indicates that a type has no internal padding bytes. You will need to derive or implement this trait for all types used with `Atomic`.\n\nThis library will use native atomic instructions if possible, and will otherwise fall back to a lock-based mechanism. You can use the `Atomic::::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.\n\nThis crate uses `#![no_std]` and only depends on libcore.\n\n[bytemuck]: https://docs.rs/bytemuck\n\n[Documentation](https://docs.rs/atomic)\n\n## Features\n\nThis crate has the following [Cargo\nfeatures](https://doc.rust-lang.org/cargo/reference/features.html):\n\n* `fallback`: Fall back to locks when atomic instructions cannot be\n used. (Enabled by default.)\n* `serde`: Enables serialization and serialization of `Atomic` with\n [serde](https://docs.rs/serde/latest/serde/).\n\n## Usage\n\nAdd this to your `Cargo.toml`:\n\n```toml\n[dependencies]\natomic = \"0.6\"\n```\n\nand this to your crate root:\n\n```rust\nextern crate atomic;\n```\n\n## License\n\nLicensed under either of\n\n * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)\n * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)\n\nat your option.\n\n### Contribution\n\nUnless you explicitly state otherwise, any contribution intentionally submitted\nfor inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any\nadditional terms or conditions.\n" }, { "path": "src/fallback.rs", "content": "// Copyright 2016 Amanieu d'Antras\n//\n// Licensed under the Apache License, Version 2.0, or the MIT license , at your option. This file may not be\n// copied, modified, or distributed except according to those terms.\n\nuse core::cmp;\nuse core::hint;\nuse core::num::Wrapping;\nuse core::ops;\nuse core::ptr;\nuse core::sync::atomic::{AtomicUsize, Ordering};\n\nuse bytemuck::NoUninit;\n\n// We use an AtomicUsize instead of an AtomicBool because it performs better\n// on architectures that don't have byte-sized atomics.\n//\n// We give each spinlock its own cache line to avoid false sharing.\n#[repr(align(64))]\nstruct SpinLock(AtomicUsize);\n\nimpl SpinLock {\n fn lock(&self) {\n while self\n .0\n .compare_exchange_weak(0, 1, Ordering::Acquire, Ordering::Relaxed)\n .is_err()\n {\n while self.0.load(Ordering::Relaxed) != 0 {\n hint::spin_loop();\n }\n }\n }\n\n fn unlock(&self) {\n self.0.store(0, Ordering::Release);\n }\n}\n\n// A big array of spinlocks which we use to guard atomic accesses. A spinlock is\n// chosen based on a hash of the address of the atomic object, which helps to\n// reduce contention compared to a single global lock.\nmacro_rules! array {\n (@accum (0, $($_es:expr),*) -> ($($body:tt)*))\n => {array!(@as_expr [$($body)*])};\n (@accum (1, $($es:expr),*) -> ($($body:tt)*))\n => {array!(@accum (0, $($es),*) -> ($($body)* $($es,)*))};\n (@accum (2, $($es:expr),*) -> ($($body:tt)*))\n => {array!(@accum (0, $($es),*) -> ($($body)* $($es,)* $($es,)*))};\n (@accum (4, $($es:expr),*) -> ($($body:tt)*))\n => {array!(@accum (2, $($es,)* $($es),*) -> ($($body)*))};\n (@accum (8, $($es:expr),*) -> ($($body:tt)*))\n => {array!(@accum (4, $($es,)* $($es),*) -> ($($body)*))};\n (@accum (16, $($es:expr),*) -> ($($body:tt)*))\n => {array!(@accum (8, $($es,)* $($es),*) -> ($($body)*))};\n (@accum (32, $($es:expr),*) -> ($($body:tt)*))\n => {array!(@accum (16, $($es,)* $($es),*) -> ($($body)*))};\n (@accum (64, $($es:expr),*) -> ($($body:tt)*))\n => {array!(@accum (32, $($es,)* $($es),*) -> ($($body)*))};\n\n (@as_expr $e:expr) => {$e};\n\n [$e:expr; $n:tt] => { array!(@accum ($n, $e) -> ()) };\n}\nstatic SPINLOCKS: [SpinLock; 64] = array![SpinLock(AtomicUsize::new(0)); 64];\n\n// Spinlock pointer hashing function from compiler-rt\n#[inline]\nfn lock_for_addr(addr: usize) -> &'static SpinLock {\n // Disregard the lowest 4 bits. We want all values that may be part of the\n // same memory operation to hash to the same value and therefore use the same\n // lock.\n let mut hash = addr >> 4;\n // Use the next bits as the basis for the hash\n let low = hash & (SPINLOCKS.len() - 1);\n // Now use the high(er) set of bits to perturb the hash, so that we don't\n // get collisions from atomic fields in a single object\n hash >>= 16;\n hash ^= low;\n // Return a pointer to the lock to use\n &SPINLOCKS[hash & (SPINLOCKS.len() - 1)]\n}\n\n#[inline]\nfn lock(addr: usize) -> LockGuard {\n let lock = lock_for_addr(addr);\n lock.lock();\n LockGuard(lock)\n}\n\nstruct LockGuard(&'static SpinLock);\nimpl Drop for LockGuard {\n #[inline]\n fn drop(&mut self) {\n self.0.unlock();\n }\n}\n\n#[inline]\npub unsafe fn atomic_load(dst: *mut T) -> T {\n let _l = lock(dst as usize);\n ptr::read(dst)\n}\n\n#[inline]\npub unsafe fn atomic_store(dst: *mut T, val: T) {\n let _l = lock(dst as usize);\n ptr::write(dst, val);\n}\n\n#[inline]\npub unsafe fn atomic_swap(dst: *mut T, val: T) -> T {\n let _l = lock(dst as usize);\n ptr::replace(dst, val)\n}\n\n#[inline]\npub unsafe fn atomic_compare_exchange(\n dst: *mut T,\n current: T,\n new: T,\n) -> Result {\n let _l = lock(dst as usize);\n let result = ptr::read(dst);\n // compare_exchange compares with memcmp instead of Eq\n let a = bytemuck::bytes_of(&result);\n let b = bytemuck::bytes_of(¤t);\n if a == b {\n ptr::write(dst, new);\n Ok(result)\n } else {\n Err(result)\n }\n}\n\n#[inline]\npub unsafe fn atomic_add(dst: *mut T, val: T) -> T\nwhere\n Wrapping: ops::Add>,\n{\n let _l = lock(dst as usize);\n let result = ptr::read(dst);\n ptr::write(dst, (Wrapping(result) + Wrapping(val)).0);\n result\n}\n\n#[inline]\npub unsafe fn atomic_sub(dst: *mut T, val: T) -> T\nwhere\n Wrapping: ops::Sub>,\n{\n let _l = lock(dst as usize);\n let result = ptr::read(dst);\n ptr::write(dst, (Wrapping(result) - Wrapping(val)).0);\n result\n}\n\n#[inline]\npub unsafe fn atomic_and>(dst: *mut T, val: T) -> T {\n let _l = lock(dst as usize);\n let result = ptr::read(dst);\n ptr::write(dst, result & val);\n result\n}\n\n#[inline]\npub unsafe fn atomic_or>(dst: *mut T, val: T) -> T {\n let _l = lock(dst as usize);\n let result = ptr::read(dst);\n ptr::write(dst, result | val);\n result\n}\n\n#[inline]\npub unsafe fn atomic_xor>(dst: *mut T, val: T) -> T {\n let _l = lock(dst as usize);\n let result = ptr::read(dst);\n ptr::write(dst, result ^ val);\n result\n}\n\n#[inline]\npub unsafe fn atomic_min(dst: *mut T, val: T) -> T {\n let _l = lock(dst as usize);\n let result = ptr::read(dst);\n ptr::write(dst, cmp::min(result, val));\n result\n}\n\n#[inline]\npub unsafe fn atomic_max(dst: *mut T, val: T) -> T {\n let _l = lock(dst as usize);\n let result = ptr::read(dst);\n ptr::write(dst, cmp::max(result, val));\n result\n}\n" }, { "path": "src/lib.rs", "content": "// Copyright 2016 Amanieu d'Antras\n//\n// Licensed under the Apache License, Version 2.0, or the MIT license , at your option. This file may not be\n// copied, modified, or distributed except according to those terms.\n\n//! Generic `Atomic` wrapper type\n//!\n//! Atomic types provide primitive shared-memory communication between\n//! threads, and are the building blocks of other concurrent types.\n//!\n//! This library defines a generic atomic wrapper type `Atomic` for all\n//! `T: NoUninit` types.\n//! Atomic types present operations that, when used correctly, synchronize\n//! updates between threads.\n//!\n//! The `NoUninit` bound is from the [bytemuck] crate, and indicates that a\n//! type has no internal padding bytes. You will need to derive or implement\n//! this trait for all types used with `Atomic`.\n//!\n//! Each method takes an `Ordering` which represents the strength of\n//! the memory barrier for that operation. These orderings are the\n//! same as [LLVM atomic orderings][1].\n//!\n//! [1]: http://llvm.org/docs/LangRef.html#memory-model-for-concurrent-operations\n//!\n//! Atomic variables are safe to share between threads (they implement `Sync`)\n//! but they do not themselves provide the mechanism for sharing. The most\n//! common way to share an atomic variable is to put it into an `Arc` (an\n//! atomically-reference-counted shared pointer).\n//!\n//! Most atomic types may be stored in static variables, initialized using\n//! the `const fn` constructors. Atomic statics are often used for lazy global\n//! initialization.\n//!\n//! [bytemuck]: https://docs.rs/bytemuck\n\n#![warn(missing_docs)]\n#![warn(rust_2018_idioms)]\n#![no_std]\n#![cfg_attr(feature = \"nightly\", feature(integer_atomics))]\n\n#[cfg(any(test, feature = \"std\"))]\n#[macro_use]\nextern crate std;\n\nuse core::mem::MaybeUninit;\n// Re-export some useful definitions from libcore\npub use core::sync::atomic::{fence, Ordering};\n\nuse core::cell::UnsafeCell;\nuse core::fmt;\n\n#[cfg(feature = \"std\")]\nuse std::panic::RefUnwindSafe;\n\nuse bytemuck::NoUninit;\n\n#[cfg(feature = \"fallback\")]\nmod fallback;\nmod ops;\n\n/// A generic atomic wrapper type which allows an object to be safely shared\n/// between threads.\n#[repr(transparent)]\npub struct Atomic {\n // The MaybeUninit is here to work around rust-lang/rust#87341.\n v: UnsafeCell>,\n}\n\n// Atomic is only Sync if T is Send\nunsafe impl Sync for Atomic {}\n\n// Given that atomicity is guaranteed, Atomic is RefUnwindSafe if T is\n//\n// This is trivially correct for native lock-free atomic types. For those whose\n// atomicity is emulated using a spinlock, it is still correct because the\n// `Atomic` API does not allow doing any panic-inducing operation after writing\n// to the target object.\n#[cfg(feature = \"std\")]\nimpl RefUnwindSafe for Atomic {}\n\nimpl Default for Atomic {\n #[inline]\n fn default() -> Self {\n Self::new(Default::default())\n }\n}\n\nimpl fmt::Debug for Atomic {\n fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {\n f.debug_tuple(\"Atomic\")\n .field(&self.load(Ordering::Relaxed))\n .finish()\n }\n}\n\nimpl Atomic {\n /// Creates a new `Atomic`.\n #[inline]\n pub const fn new(v: T) -> Atomic {\n Atomic {\n v: UnsafeCell::new(MaybeUninit::new(v)),\n }\n }\n\n /// Checks if `Atomic` objects of this type are lock-free.\n ///\n /// If an `Atomic` is not lock-free then it may be implemented using locks\n /// internally, which makes it unsuitable for some situations (such as\n /// communicating with a signal handler).\n #[inline]\n pub const fn is_lock_free() -> bool {\n ops::atomic_is_lock_free::()\n }\n}\n\nimpl Atomic {\n #[inline]\n fn inner_ptr(&self) -> *mut T {\n self.v.get() as *mut T\n }\n\n /// Returns a mutable reference to the underlying type.\n ///\n /// This is safe because the mutable reference guarantees that no other threads are\n /// concurrently accessing the atomic data.\n #[inline]\n pub fn get_mut(&mut self) -> &mut T {\n unsafe { &mut *self.inner_ptr() }\n }\n\n /// Consumes the atomic and returns the contained value.\n ///\n /// This is safe because passing `self` by value guarantees that no other threads are\n /// concurrently accessing the atomic data.\n #[inline]\n pub fn into_inner(self) -> T {\n unsafe { self.v.into_inner().assume_init() }\n }\n\n /// Loads a value from the `Atomic`.\n ///\n /// `load` takes an `Ordering` argument which describes the memory ordering\n /// of this operation.\n ///\n /// # Panics\n ///\n /// Panics if `order` is `Release` or `AcqRel`.\n #[inline]\n pub fn load(&self, order: Ordering) -> T {\n unsafe { ops::atomic_load(self.inner_ptr(), order) }\n }\n\n /// Stores a value into the `Atomic`.\n ///\n /// `store` takes an `Ordering` argument which describes the memory ordering\n /// of this operation.\n ///\n /// # Panics\n ///\n /// Panics if `order` is `Acquire` or `AcqRel`.\n #[inline]\n pub fn store(&self, val: T, order: Ordering) {\n unsafe {\n ops::atomic_store(self.inner_ptr(), val, order);\n }\n }\n\n /// Stores a value into the `Atomic`, returning the old value.\n ///\n /// `swap` takes an `Ordering` argument which describes the memory ordering\n /// of this operation.\n #[inline]\n pub fn swap(&self, val: T, order: Ordering) -> T {\n unsafe { ops::atomic_swap(self.inner_ptr(), val, order) }\n }\n\n /// Stores a value into the `Atomic` if the current value is the same as the\n /// `current` value.\n ///\n /// The return value is a result indicating whether the new value was\n /// written and containing the previous value. On success this value is\n /// guaranteed to be equal to `new`.\n ///\n /// `compare_exchange` takes two `Ordering` arguments to describe the memory\n /// ordering of this operation. The first describes the required ordering if\n /// the operation succeeds while the second describes the required ordering\n /// when the operation fails. The failure ordering can't be `Release` or\n /// `AcqRel` and must be equivalent or weaker than the success ordering.\n #[inline]\n pub fn compare_exchange(\n &self,\n current: T,\n new: T,\n success: Ordering,\n failure: Ordering,\n ) -> Result {\n unsafe { ops::atomic_compare_exchange(self.inner_ptr(), current, new, success, failure) }\n }\n\n /// Stores a value into the `Atomic` if the current value is the same as the\n /// `current` value.\n ///\n /// Unlike `compare_exchange`, this function is allowed to spuriously fail\n /// even when the comparison succeeds, which can result in more efficient\n /// code on some platforms. The return value is a result indicating whether\n /// the new value was written and containing the previous value.\n ///\n /// `compare_exchange` takes two `Ordering` arguments to describe the memory\n /// ordering of this operation. The first describes the required ordering if\n /// the operation succeeds while the second describes the required ordering\n /// when the operation fails. The failure ordering can't be `Release` or\n /// `AcqRel` and must be equivalent or weaker than the success ordering.\n /// success ordering.\n #[inline]\n pub fn compare_exchange_weak(\n &self,\n current: T,\n new: T,\n success: Ordering,\n failure: Ordering,\n ) -> Result {\n unsafe {\n ops::atomic_compare_exchange_weak(self.inner_ptr(), current, new, success, failure)\n }\n }\n\n /// Fetches the value, and applies a function to it that returns an optional\n /// new value. Returns a `Result` of `Ok(previous_value)` if the function returned `Some(_)`, else\n /// `Err(previous_value)`.\n ///\n /// Note: This may call the function multiple times if the value has been changed from other threads in\n /// the meantime, as long as the function returns `Some(_)`, but the function will have been applied\n /// only once to the stored value.\n ///\n /// `fetch_update` takes two [`Ordering`] arguments to describe the memory ordering of this operation.\n /// The first describes the required ordering for when the operation finally succeeds while the second\n /// describes the required ordering for loads. These correspond to the success and failure orderings of\n /// [`compare_exchange`] respectively.\n ///\n /// Using [`Acquire`] as success ordering makes the store part\n /// of this operation [`Relaxed`], and using [`Release`] makes the final successful load\n /// [`Relaxed`]. The (failed) load ordering can only be [`SeqCst`], [`Acquire`] or [`Relaxed`]\n /// and must be equivalent to or weaker than the success ordering.\n ///\n /// [`compare_exchange`]: #method.compare_exchange\n /// [`Ordering`]: enum.Ordering.html\n /// [`Relaxed`]: enum.Ordering.html#variant.Relaxed\n /// [`Release`]: enum.Ordering.html#variant.Release\n /// [`Acquire`]: enum.Ordering.html#variant.Acquire\n /// [`SeqCst`]: enum.Ordering.html#variant.SeqCst\n ///\n /// # Examples\n ///\n /// ```rust\n /// use atomic::{Atomic, Ordering};\n ///\n /// let x = Atomic::new(7);\n /// assert_eq!(x.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |_| None), Err(7));\n /// assert_eq!(x.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |x| Some(x + 1)), Ok(7));\n /// assert_eq!(x.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |x| Some(x + 1)), Ok(8));\n /// assert_eq!(x.load(Ordering::SeqCst), 9);\n /// ```\n #[inline]\n pub fn fetch_update(\n &self,\n set_order: Ordering,\n fetch_order: Ordering,\n mut f: F,\n ) -> Result\n where\n F: FnMut(T) -> Option,\n {\n let mut prev = self.load(fetch_order);\n while let Some(next) = f(prev) {\n match self.compare_exchange_weak(prev, next, set_order, fetch_order) {\n x @ Ok(_) => return x,\n Err(next_prev) => prev = next_prev,\n }\n }\n Err(prev)\n }\n}\n\nimpl Atomic {\n /// Logical \"and\" with a boolean value.\n ///\n /// Performs a logical \"and\" operation on the current value and the argument\n /// `val`, and sets the new value to the result.\n ///\n /// Returns the previous value.\n #[inline]\n pub fn fetch_and(&self, val: bool, order: Ordering) -> bool {\n unsafe { ops::atomic_and(self.inner_ptr(), val, order) }\n }\n\n /// Logical \"or\" with a boolean value.\n ///\n /// Performs a logical \"or\" operation on the current value and the argument\n /// `val`, and sets the new value to the result.\n ///\n /// Returns the previous value.\n #[inline]\n pub fn fetch_or(&self, val: bool, order: Ordering) -> bool {\n unsafe { ops::atomic_or(self.inner_ptr(), val, order) }\n }\n\n /// Logical \"xor\" with a boolean value.\n ///\n /// Performs a logical \"xor\" operation on the current value and the argument\n /// `val`, and sets the new value to the result.\n ///\n /// Returns the previous value.\n #[inline]\n pub fn fetch_xor(&self, val: bool, order: Ordering) -> bool {\n unsafe { ops::atomic_xor(self.inner_ptr(), val, order) }\n }\n}\n\nmacro_rules! atomic_ops_common {\n ($($t:ty)*) => ($(\n impl Atomic<$t> {\n /// Add to the current value, returning the previous value.\n #[inline]\n pub fn fetch_add(&self, val: $t, order: Ordering) -> $t {\n unsafe { ops::atomic_add(self.inner_ptr(), val, order) }\n }\n\n /// Subtract from the current value, returning the previous value.\n #[inline]\n pub fn fetch_sub(&self, val: $t, order: Ordering) -> $t {\n unsafe { ops::atomic_sub(self.inner_ptr(), val, order) }\n }\n\n /// Bitwise and with the current value, returning the previous value.\n #[inline]\n pub fn fetch_and(&self, val: $t, order: Ordering) -> $t {\n unsafe { ops::atomic_and(self.inner_ptr(), val, order) }\n }\n\n /// Bitwise or with the current value, returning the previous value.\n #[inline]\n pub fn fetch_or(&self, val: $t, order: Ordering) -> $t {\n unsafe { ops::atomic_or(self.inner_ptr(), val, order) }\n }\n\n /// Bitwise xor with the current value, returning the previous value.\n #[inline]\n pub fn fetch_xor(&self, val: $t, order: Ordering) -> $t {\n unsafe { ops::atomic_xor(self.inner_ptr(), val, order) }\n }\n }\n )*);\n}\nmacro_rules! atomic_ops_signed {\n ($($t:ty)*) => (\n atomic_ops_common!{ $($t)* }\n $(\n impl Atomic<$t> {\n /// Minimum with the current value.\n #[inline]\n pub fn fetch_min(&self, val: $t, order: Ordering) -> $t {\n unsafe { ops::atomic_min(self.inner_ptr(), val, order) }\n }\n\n /// Maximum with the current value.\n #[inline]\n pub fn fetch_max(&self, val: $t, order: Ordering) -> $t {\n unsafe { ops::atomic_max(self.inner_ptr(), val, order) }\n }\n }\n )*\n );\n}\nmacro_rules! atomic_ops_unsigned {\n ($($t:ty)*) => (\n atomic_ops_common!{ $($t)* }\n $(\n impl Atomic<$t> {\n /// Minimum with the current value.\n #[inline]\n pub fn fetch_min(&self, val: $t, order: Ordering) -> $t {\n unsafe { ops::atomic_umin(self.inner_ptr(), val, order) }\n }\n\n /// Maximum with the current value.\n #[inline]\n pub fn fetch_max(&self, val: $t, order: Ordering) -> $t {\n unsafe { ops::atomic_umax(self.inner_ptr(), val, order) }\n }\n }\n )*\n );\n}\natomic_ops_signed! { i8 i16 i32 i64 isize i128 }\natomic_ops_unsigned! { u8 u16 u32 u64 usize u128 }\n\n#[cfg(feature = \"serde\")]\nmod serde_impl;\n\n#[cfg(test)]\nmod tests {\n use super::{Atomic, Ordering::*};\n use bytemuck::NoUninit;\n use core::mem;\n\n #[derive(Copy, Clone, Eq, PartialEq, Debug, Default, NoUninit)]\n #[cfg_attr(feature = \"serde\", derive(serde::Serialize, serde::Deserialize))]\n #[repr(C)]\n struct Foo(u8, u8);\n\n #[derive(Copy, Clone, Eq, PartialEq, Debug, Default, NoUninit)]\n #[cfg_attr(feature = \"serde\", derive(serde::Serialize, serde::Deserialize))]\n #[repr(C)]\n struct Bar(u64, u64);\n\n #[derive(Copy, Clone, Eq, PartialEq, Debug, Default, NoUninit)]\n #[cfg_attr(feature = \"serde\", derive(serde::Serialize, serde::Deserialize))]\n #[repr(C)]\n struct Quux(u32);\n\n #[cfg(feature = \"serde\")]\n fn assert_serde(atomic: &Atomic, value: T)\n where\n T: NoUninit\n + PartialEq\n + std::fmt::Debug\n + for<'a> serde::Deserialize<'a>\n + serde::Serialize,\n {\n let s = serde_json::to_string(atomic).unwrap();\n assert_eq!(s, serde_json::to_string(&value).unwrap());\n\n let x: Atomic = serde_json::from_str(&s).unwrap();\n assert_eq!(x.load(SeqCst), value);\n }\n\n #[test]\n fn atomic_bool() {\n let a = Atomic::new(false);\n assert_eq!(\n Atomic::::is_lock_free(),\n cfg!(target_has_atomic = \"8\"),\n );\n assert_eq!(format!(\"{:?}\", a), \"Atomic(false)\");\n assert_eq!(a.load(SeqCst), false);\n a.store(true, SeqCst);\n assert_eq!(a.swap(false, SeqCst), true);\n assert_eq!(a.compare_exchange(true, false, SeqCst, SeqCst), Err(false));\n assert_eq!(a.compare_exchange(false, true, SeqCst, SeqCst), Ok(false));\n assert_eq!(a.fetch_and(false, SeqCst), true);\n assert_eq!(a.fetch_or(true, SeqCst), false);\n assert_eq!(a.fetch_xor(false, SeqCst), true);\n assert_eq!(a.load(SeqCst), true);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, true);\n }\n\n #[test]\n fn atomic_i8() {\n let a = Atomic::new(0i8);\n assert_eq!(Atomic::::is_lock_free(), cfg!(target_has_atomic = \"8\"));\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n // Make sure overflows are handled correctly\n assert_eq!(a.fetch_sub(-56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), -74);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(-25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n #[test]\n fn atomic_i16() {\n let a = Atomic::new(0i16);\n assert_eq!(\n Atomic::::is_lock_free(),\n cfg!(target_has_atomic = \"16\")\n );\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(-56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 182);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(-25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n #[test]\n fn atomic_i32() {\n let a = Atomic::new(0i32);\n assert_eq!(\n Atomic::::is_lock_free(),\n cfg!(target_has_atomic = \"32\")\n );\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(-56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 182);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(-25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n // on 32-bit x86 64 bit atomics exist, but they can't be used to implement\n // atomic because AtomicI64 has a greater alignment requirement than\n // i64.\n #[cfg(any(\n feature = \"fallback\",\n all(target_has_atomic = \"64\", not(target_arch = \"x86\"))\n ))]\n #[test]\n fn atomic_i64() {\n let a = Atomic::new(0i64);\n assert_eq!(\n Atomic::::is_lock_free(),\n cfg!(target_has_atomic = \"64\") && mem::align_of::() == 8\n );\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(-56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 182);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(-25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n #[cfg(any(feature = \"fallback\", target_has_atomic = \"128\"))]\n #[test]\n fn atomic_i128() {\n let a = Atomic::new(0i128);\n assert_eq!(\n Atomic::::is_lock_free(),\n cfg!(feature = \"nightly\") & cfg!(target_has_atomic = \"128\")\n );\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(-56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 182);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(-25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n #[test]\n fn atomic_isize() {\n let a = Atomic::new(0isize);\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(-56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 182);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(-25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n #[test]\n fn atomic_u8() {\n let a = Atomic::new(0u8);\n assert_eq!(Atomic::::is_lock_free(), cfg!(target_has_atomic = \"8\"));\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 70);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n #[test]\n fn atomic_u16() {\n let a = Atomic::new(0u16);\n assert_eq!(\n Atomic::::is_lock_free(),\n cfg!(target_has_atomic = \"16\")\n );\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 70);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n #[test]\n fn atomic_u32() {\n let a = Atomic::new(0u32);\n assert_eq!(\n Atomic::::is_lock_free(),\n cfg!(target_has_atomic = \"32\")\n );\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 70);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n // on 32-bit x86 64 bit atomics exist, but they can't be used to implement\n // atomic because AtomicU64 has a greater alignment requirement than\n // u64.\n #[cfg(any(\n feature = \"fallback\",\n all(target_has_atomic = \"64\", not(target_arch = \"x86\"))\n ))]\n #[test]\n fn atomic_u64() {\n let a = Atomic::new(0u64);\n assert_eq!(\n Atomic::::is_lock_free(),\n cfg!(target_has_atomic = \"64\") && mem::align_of::() == 8\n );\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 70);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n #[cfg(any(feature = \"fallback\", target_has_atomic = \"128\"))]\n #[test]\n fn atomic_u128() {\n let a = Atomic::new(0u128);\n assert_eq!(\n Atomic::::is_lock_free(),\n cfg!(feature = \"nightly\") & cfg!(target_has_atomic = \"128\")\n );\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 70);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n #[test]\n fn atomic_usize() {\n let a = Atomic::new(0usize);\n assert_eq!(format!(\"{:?}\", a), \"Atomic(0)\");\n assert_eq!(a.load(SeqCst), 0);\n a.store(1, SeqCst);\n assert_eq!(a.swap(2, SeqCst), 1);\n assert_eq!(a.compare_exchange(5, 45, SeqCst, SeqCst), Err(2));\n assert_eq!(a.compare_exchange(2, 3, SeqCst, SeqCst), Ok(2));\n assert_eq!(a.fetch_add(123, SeqCst), 3);\n assert_eq!(a.fetch_sub(56, SeqCst), 126);\n assert_eq!(a.fetch_and(7, SeqCst), 70);\n assert_eq!(a.fetch_or(64, SeqCst), 6);\n assert_eq!(a.fetch_xor(1, SeqCst), 70);\n assert_eq!(a.fetch_min(30, SeqCst), 71);\n assert_eq!(a.fetch_max(25, SeqCst), 30);\n assert_eq!(a.load(SeqCst), 30);\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, 30);\n }\n\n #[cfg(feature = \"fallback\")]\n #[test]\n fn atomic_foo() {\n let a = Atomic::default();\n assert_eq!(Atomic::::is_lock_free(), false);\n assert_eq!(format!(\"{:?}\", a), \"Atomic(Foo(0, 0))\");\n assert_eq!(a.load(SeqCst), Foo(0, 0));\n a.store(Foo(1, 1), SeqCst);\n assert_eq!(a.swap(Foo(2, 2), SeqCst), Foo(1, 1));\n assert_eq!(\n a.compare_exchange(Foo(5, 5), Foo(45, 45), SeqCst, SeqCst),\n Err(Foo(2, 2))\n );\n assert_eq!(\n a.compare_exchange(Foo(2, 2), Foo(3, 3), SeqCst, SeqCst),\n Ok(Foo(2, 2))\n );\n assert_eq!(a.load(SeqCst), Foo(3, 3));\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, Foo(3, 3));\n }\n\n #[cfg(feature = \"fallback\")]\n #[test]\n fn atomic_bar() {\n let a = Atomic::default();\n assert_eq!(Atomic::::is_lock_free(), false);\n assert_eq!(format!(\"{:?}\", a), \"Atomic(Bar(0, 0))\");\n assert_eq!(a.load(SeqCst), Bar(0, 0));\n a.store(Bar(1, 1), SeqCst);\n assert_eq!(a.swap(Bar(2, 2), SeqCst), Bar(1, 1));\n assert_eq!(\n a.compare_exchange(Bar(5, 5), Bar(45, 45), SeqCst, SeqCst),\n Err(Bar(2, 2))\n );\n assert_eq!(\n a.compare_exchange(Bar(2, 2), Bar(3, 3), SeqCst, SeqCst),\n Ok(Bar(2, 2))\n );\n assert_eq!(a.load(SeqCst), Bar(3, 3));\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, Bar(3, 3));\n }\n\n #[test]\n fn atomic_quxx() {\n let a = Atomic::default();\n assert_eq!(\n Atomic::::is_lock_free(),\n cfg!(target_has_atomic = \"32\")\n );\n assert_eq!(format!(\"{:?}\", a), \"Atomic(Quux(0))\");\n assert_eq!(a.load(SeqCst), Quux(0));\n a.store(Quux(1), SeqCst);\n assert_eq!(a.swap(Quux(2), SeqCst), Quux(1));\n assert_eq!(\n a.compare_exchange(Quux(5), Quux(45), SeqCst, SeqCst),\n Err(Quux(2))\n );\n assert_eq!(\n a.compare_exchange(Quux(2), Quux(3), SeqCst, SeqCst),\n Ok(Quux(2))\n );\n assert_eq!(a.load(SeqCst), Quux(3));\n\n #[cfg(feature = \"serde\")]\n assert_serde(&a, Quux(3));\n }\n}\n" }, { "path": "src/ops.rs", "content": "// Copyright 2016 Amanieu d'Antras\n//\n// Licensed under the Apache License, Version 2.0, or the MIT license , at your option. This file may not be\n// copied, modified, or distributed except according to those terms.\n\nuse bytemuck::NoUninit;\n\n#[cfg(feature = \"fallback\")]\nuse crate::fallback;\nuse core::cmp;\nuse core::mem;\nuse core::num::Wrapping;\nuse core::ops;\nuse core::sync::atomic::Ordering;\n\nmacro_rules! match_atomic {\n ($type:ident, $atomic:ident, $impl:expr, $fallback_impl:expr) => {\n match mem::size_of::<$type>() {\n #[cfg(target_has_atomic = \"8\")]\n 1 if mem::align_of::<$type>() >= 1 => {\n type $atomic = core::sync::atomic::AtomicU8;\n\n $impl\n }\n #[cfg(target_has_atomic = \"16\")]\n 2 if mem::align_of::<$type>() >= 2 => {\n type $atomic = core::sync::atomic::AtomicU16;\n\n $impl\n }\n #[cfg(target_has_atomic = \"32\")]\n 4 if mem::align_of::<$type>() >= 4 => {\n type $atomic = core::sync::atomic::AtomicU32;\n\n $impl\n }\n #[cfg(target_has_atomic = \"64\")]\n 8 if mem::align_of::<$type>() >= 8 => {\n type $atomic = core::sync::atomic::AtomicU64;\n\n $impl\n }\n #[cfg(all(feature = \"nightly\", target_has_atomic = \"128\"))]\n 16 if mem::align_of::<$type>() >= 16 => {\n type $atomic = core::sync::atomic::AtomicU128;\n\n $impl\n }\n #[cfg(feature = \"fallback\")]\n _ => $fallback_impl,\n #[cfg(not(feature = \"fallback\"))]\n _ => panic!(\"Atomic operations for type `{}` are not available as the `fallback` feature of the `atomic` crate is disabled.\", core::any::type_name::<$type>()),\n }\n };\n}\n\nmacro_rules! match_signed_atomic {\n ($type:ident, $atomic:ident, $impl:expr, $fallback_impl:expr) => {\n match mem::size_of::<$type>() {\n #[cfg(target_has_atomic = \"8\")]\n 1 if mem::align_of::<$type>() >= 1 => {\n type $atomic = core::sync::atomic::AtomicI8;\n\n $impl\n }\n #[cfg(target_has_atomic = \"16\")]\n 2 if mem::align_of::<$type>() >= 2 => {\n type $atomic = core::sync::atomic::AtomicI16;\n\n $impl\n }\n #[cfg(target_has_atomic = \"32\")]\n 4 if mem::align_of::<$type>() >= 4 => {\n type $atomic = core::sync::atomic::AtomicI32;\n\n $impl\n }\n #[cfg(target_has_atomic = \"64\")]\n 8 if mem::align_of::<$type>() >= 8 => {\n type $atomic = core::sync::atomic::AtomicI64;\n\n $impl\n }\n #[cfg(all(feature = \"nightly\", target_has_atomic = \"128\"))]\n 16 if mem::align_of::<$type>() >= 16 => {\n type $atomic = core::sync::atomic::AtomicI128;\n\n $impl\n }\n #[cfg(feature = \"fallback\")]\n _ => $fallback_impl,\n #[cfg(not(feature = \"fallback\"))]\n _ => panic!(\"Atomic operations for type `{}` are not available as the `fallback` feature of the `atomic` crate is disabled.\", core::any::type_name::<$type>()),\n }\n };\n}\n\n#[inline]\npub const fn atomic_is_lock_free() -> bool {\n let size = mem::size_of::();\n let align = mem::align_of::();\n\n (cfg!(target_has_atomic = \"8\") & (size == 1) & (align >= 1))\n | (cfg!(target_has_atomic = \"16\") & (size == 2) & (align >= 2))\n | (cfg!(target_has_atomic = \"32\") & (size == 4) & (align >= 4))\n | (cfg!(target_has_atomic = \"64\") & (size == 8) & (align >= 8))\n | (cfg!(feature = \"nightly\")\n & cfg!(target_has_atomic = \"128\")\n & (size == 16)\n & (align >= 16))\n}\n\n#[inline]\npub unsafe fn atomic_load(dst: *mut T, order: Ordering) -> T {\n match_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).load(order)),\n fallback::atomic_load(dst)\n )\n}\n\n#[inline]\npub unsafe fn atomic_store(dst: *mut T, val: T, order: Ordering) {\n match_atomic!(\n T,\n A,\n (*(dst as *const A)).store(mem::transmute_copy(&val), order),\n fallback::atomic_store(dst, val)\n )\n}\n\n#[inline]\npub unsafe fn atomic_swap(dst: *mut T, val: T, order: Ordering) -> T {\n match_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).swap(mem::transmute_copy(&val), order)),\n fallback::atomic_swap(dst, val)\n )\n}\n\n#[inline]\nunsafe fn map_result(r: Result) -> Result {\n match r {\n Ok(x) => Ok(mem::transmute_copy(&x)),\n Err(x) => Err(mem::transmute_copy(&x)),\n }\n}\n\n#[inline]\npub unsafe fn atomic_compare_exchange(\n dst: *mut T,\n current: T,\n new: T,\n success: Ordering,\n failure: Ordering,\n) -> Result {\n match_atomic!(\n T,\n A,\n map_result((*(dst as *const A)).compare_exchange(\n mem::transmute_copy(¤t),\n mem::transmute_copy(&new),\n success,\n failure,\n )),\n fallback::atomic_compare_exchange(dst, current, new)\n )\n}\n\n#[inline]\npub unsafe fn atomic_compare_exchange_weak(\n dst: *mut T,\n current: T,\n new: T,\n success: Ordering,\n failure: Ordering,\n) -> Result {\n match_atomic!(\n T,\n A,\n map_result((*(dst as *const A)).compare_exchange_weak(\n mem::transmute_copy(¤t),\n mem::transmute_copy(&new),\n success,\n failure,\n )),\n fallback::atomic_compare_exchange(dst, current, new)\n )\n}\n\n#[inline]\npub unsafe fn atomic_add(dst: *mut T, val: T, order: Ordering) -> T\nwhere\n Wrapping: ops::Add>,\n{\n match_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).fetch_add(mem::transmute_copy(&val), order),),\n fallback::atomic_add(dst, val)\n )\n}\n\n#[inline]\npub unsafe fn atomic_sub(dst: *mut T, val: T, order: Ordering) -> T\nwhere\n Wrapping: ops::Sub>,\n{\n match_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).fetch_sub(mem::transmute_copy(&val), order),),\n fallback::atomic_sub(dst, val)\n )\n}\n\n#[inline]\npub unsafe fn atomic_and>(\n dst: *mut T,\n val: T,\n order: Ordering,\n) -> T {\n match_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).fetch_and(mem::transmute_copy(&val), order),),\n fallback::atomic_and(dst, val)\n )\n}\n\n#[inline]\npub unsafe fn atomic_or>(\n dst: *mut T,\n val: T,\n order: Ordering,\n) -> T {\n match_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).fetch_or(mem::transmute_copy(&val), order),),\n fallback::atomic_or(dst, val)\n )\n}\n\n#[inline]\npub unsafe fn atomic_xor>(\n dst: *mut T,\n val: T,\n order: Ordering,\n) -> T {\n match_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).fetch_xor(mem::transmute_copy(&val), order),),\n fallback::atomic_xor(dst, val)\n )\n}\n\n#[inline]\npub unsafe fn atomic_min(dst: *mut T, val: T, order: Ordering) -> T {\n match_signed_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).fetch_min(mem::transmute_copy(&val), order),),\n fallback::atomic_min(dst, val)\n )\n}\n\n#[inline]\npub unsafe fn atomic_max(dst: *mut T, val: T, order: Ordering) -> T {\n match_signed_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).fetch_max(mem::transmute_copy(&val), order),),\n fallback::atomic_max(dst, val)\n )\n}\n\n#[inline]\npub unsafe fn atomic_umin(dst: *mut T, val: T, order: Ordering) -> T {\n match_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).fetch_min(mem::transmute_copy(&val), order),),\n fallback::atomic_min(dst, val)\n )\n}\n\n#[inline]\npub unsafe fn atomic_umax(dst: *mut T, val: T, order: Ordering) -> T {\n match_atomic!(\n T,\n A,\n mem::transmute_copy(&(*(dst as *const A)).fetch_max(mem::transmute_copy(&val), order),),\n fallback::atomic_max(dst, val)\n )\n}\n" }, { "path": "src/serde_impl.rs", "content": "use core::sync::atomic::Ordering;\n\nuse bytemuck::NoUninit;\nuse serde::{Deserialize, Deserializer, Serialize, Serializer};\n\nuse crate::Atomic;\n\nimpl Serialize for Atomic\nwhere\n T: NoUninit + Serialize,\n{\n fn serialize(&self, serializer: S) -> Result\n where\n S: Serializer,\n {\n // Matches the atomic ordering used in `Debug` for `Atomic`.\n self.load(Ordering::Relaxed).serialize(serializer)\n }\n}\n\nimpl<'de, T> Deserialize<'de> for Atomic\nwhere\n T: for<'a> Deserialize<'a>,\n{\n fn deserialize(deserializer: D) -> Result\n where\n D: Deserializer<'de>,\n {\n Deserialize::deserialize(deserializer).map(Self::new)\n }\n}\n" } ]