atomic_refcell-0.1.14/.cargo_vcs_info.json0000644000000001361046102023000141110ustar { "git": { "sha1": "216bba408cf6df886dca5b0fb4b1d410d46db03c" }, "path_in_vcs": "" }atomic_refcell-0.1.14/.gitignore000064400000000000000000000000221046102023000146410ustar 00000000000000target Cargo.lock atomic_refcell-0.1.14/Cargo.lock0000644000000023201046102023000120610ustar # This file is automatically @generated by Cargo. # It is not intended for manual editing. version = 3 [[package]] name = "atomic_refcell" version = "0.1.14" dependencies = [ "portable-atomic", "serde", "serde_json", ] [[package]] name = "itoa" version = "1.0.9" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "af150ab688ff2122fcef229be89cb50dd66af9e01a4ff320cc137eecc9bacc38" [[package]] name = "portable-atomic" version = "1.13.1" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49" [[package]] name = "ryu" version = "1.0.15" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "1ad4cc8da4ef723ed60bced201181d83791ad433213d8c24efffda1eec85d741" [[package]] name = "serde" version = "1.0.183" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "32ac8da02677876d532745a130fc9d8e6edfa81a269b107c5b00829b91d8eb3c" [[package]] name = "serde_json" version = "1.0.104" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "076066c5f1078eac5b722a31827a8832fe108bed65dfa75e233c89f8206e976c" dependencies = [ "itoa", "ryu", "serde", ] atomic_refcell-0.1.14/Cargo.toml0000644000000026061046102023000121130ustar # 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 = "2021" rust-version = "1.60" name = "atomic_refcell" version = "0.1.14" authors = ["Bobby Holley "] build = false autolib = false autobins = false autoexamples = false autotests = false autobenches = false description = "Threadsafe RefCell" documentation = "https://docs.rs/atomic_refcell/" readme = "README.md" license = "Apache-2.0 OR MIT" repository = "https://github.com/mozilla/atomic_refcell" [features] default = [] portable-atomic = ["dep:portable-atomic"] serde = ["dep:serde"] [lib] name = "atomic_refcell" path = "src/lib.rs" [[test]] name = "async" path = "tests/async.rs" [[test]] name = "basic" path = "tests/basic.rs" [[bench]] name = "basic" path = "benches/basic.rs" [dependencies.portable-atomic] version = "1" features = ["require-cas"] optional = true default-features = false [dependencies.serde] version = "1.0" optional = true [dev-dependencies.serde_json] version = "1.0" atomic_refcell-0.1.14/Cargo.toml.orig000064400000000000000000000011521046102023000155450ustar 00000000000000[package] name = "atomic_refcell" version = "0.1.14" authors = ["Bobby Holley "] description = "Threadsafe RefCell" license = "Apache-2.0 OR MIT" repository = "https://github.com/mozilla/atomic_refcell" documentation = "https://docs.rs/atomic_refcell/" edition = "2021" rust-version = "1.60" [dependencies] portable-atomic = { version = "1", optional = true, default-features = false, features = [ "require-cas", ] } serde = { version = "1.0", optional = true } [dev-dependencies] serde_json = "1.0" [features] default = [] portable-atomic = ["dep:portable-atomic"] serde = ["dep:serde"] atomic_refcell-0.1.14/LICENSE.APACHE000064400000000000000000000261351046102023000146130ustar 00000000000000 Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. 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See the License for the specific language governing permissions and limitations under the License. atomic_refcell-0.1.14/LICENSE.MIT000064400000000000000000000020551046102023000143160ustar 00000000000000MIT License Copyright (c) 2022 Bobby Holley Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 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. atomic_refcell-0.1.14/README.md000064400000000000000000000016661046102023000141470ustar 00000000000000# atomic_refcell A thread-safe analogue of [`RefCell`](https://doc.rust-lang.org/std/cell/struct.RefCell.html) for Rust. ## Overview [`AtomicRefCell`](https://docs.rs/atomic_refcell/) provides `RefCell`-like borrow semantics (checked at runtime, with immutable and mutable borrows) for values shared across threads. It is designed for use cases where the caller can guarantee that mutable and immutable borrows never overlap concurrently, but still requires a `Sync` type. The crate is `no_std` compatible. ## Features | Feature | Description | |---|---| | `portable-atomic` | Use [`portable-atomic`](https://crates.io/crates/portable-atomic) instead of `core::sync::atomic`. Enables support for targets without native atomic compare-and-swap instructions (e.g. `thumbv6m-none-eabi`). | | `serde` | Implement `Serialize` and `Deserialize` for `AtomicRefCell`. | ## Minimum Supported Rust Version (MSRV) Rust **1.60** or later is required. atomic_refcell-0.1.14/SECURITY.md000064400000000000000000000012671046102023000144560ustar 00000000000000# Security Policy ## Supported Versions Security updates are applied only to the latest release. ## Reporting a Vulnerability If you have discovered a security vulnerability in this project, please report it privately. **Do not disclose it as a public issue.** This gives us time to work with you to fix the issue before public exposure, reducing the chance that the exploit will be used before a patch is released. Please disclose it at [security advisory](https://github.com/bholley/atomic_refcell/security/advisories/new). This project is maintained by a team of volunteers on a reasonable-effort basis. As such, please give us at least 90 days to work on a fix before public exposure. atomic_refcell-0.1.14/benches/basic.rs000064400000000000000000000013651046102023000157220ustar 00000000000000#![feature(test)] extern crate test; use atomic_refcell::AtomicRefCell; use test::Bencher; #[derive(Default)] #[allow(dead_code)] struct Bar(u32); #[bench] fn immutable_borrow(b: &mut Bencher) { let a = AtomicRefCell::new(Bar::default()); b.iter(|| a.borrow()); } #[bench] fn immutable_second_borrow(b: &mut Bencher) { let a = AtomicRefCell::new(Bar::default()); let _first = a.borrow(); b.iter(|| a.borrow()); } #[bench] fn immutable_third_borrow(b: &mut Bencher) { let a = AtomicRefCell::new(Bar::default()); let _first = a.borrow(); let _second = a.borrow(); b.iter(|| a.borrow()); } #[bench] fn mutable_borrow(b: &mut Bencher) { let a = AtomicRefCell::new(Bar::default()); b.iter(|| a.borrow_mut()); } atomic_refcell-0.1.14/src/lib.rs000064400000000000000000000447661046102023000146030ustar 00000000000000//! Implements a container type providing RefCell-like semantics for objects //! shared across threads. //! //! RwLock is traditionally considered to be the |Sync| analogue of RefCell. //! However, for consumers that can guarantee that they will never mutably //! borrow the contents concurrently with immutable borrows, an RwLock is //! overkill, and has key disadvantages: //! * Performance: Even the fastest existing implementation of RwLock (that of //! parking_lot) performs at least two atomic operations during immutable //! borrows. This makes mutable borrows significantly cheaper than immutable //! borrows, leading to weird incentives when writing performance-critical //! code. //! * Features: Implementing AtomicRefCell on top of RwLock makes it impossible //! to implement useful things like AtomicRef{,Mut}::map. //! //! As such, we re-implement RefCell semantics from scratch with a single atomic //! reference count. The primary complication of this scheme relates to keeping //! things in a consistent state when one thread performs an illegal borrow and //! panics. Since an AtomicRefCell can be accessed by multiple threads, and since //! panics are recoverable, we need to ensure that an illegal (panicking) access by //! one thread does not lead to undefined behavior on other, still-running threads. //! //! So we represent things as follows: //! * Any value with the high bit set (so half the total refcount space) indicates //! a mutable borrow. //! * Mutable borrows perform an atomic compare-and-swap, swapping in the high bit //! if the current value is zero. If the current value is non-zero, the thread //! panics and the value is left undisturbed. //! * Immutable borrows perform an atomic increment. If the new value has the high //! bit set, the thread panics. The incremented refcount is left as-is, since it //! still represents a valid mutable borrow. When the mutable borrow is released, //! the refcount is set unconditionally to zero, clearing any stray increments by //! panicked threads. //! //! There are a few additional purely-academic complications to handle overflow, //! which are documented in the implementation. //! //! The rest of this module is mostly derived by copy-pasting the implementation of //! RefCell and fixing things up as appropriate. Certain non-threadsafe methods //! have been removed. We segment the concurrency logic from the rest of the code to //! keep the tricky parts small and easy to audit. #![no_std] #![allow(unsafe_code)] #![deny(missing_docs)] use core::cell::UnsafeCell; use core::cmp; use core::fmt; use core::fmt::{Debug, Display}; use core::marker::PhantomData; use core::ops::{Deref, DerefMut}; use core::ptr::NonNull; use core::sync::atomic; #[cfg(not(feature = "portable-atomic"))] use core::sync::atomic::AtomicUsize; #[cfg(feature = "portable-atomic")] use portable_atomic::AtomicUsize; #[cfg(feature = "serde")] use serde::{Deserialize, Serialize}; /// A threadsafe analogue to RefCell. pub struct AtomicRefCell { borrow: AtomicUsize, value: UnsafeCell, } /// An error returned by [`AtomicRefCell::try_borrow`](struct.AtomicRefCell.html#method.try_borrow). pub struct BorrowError { _private: (), } impl Debug for BorrowError { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("BorrowError").finish() } } impl Display for BorrowError { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { Display::fmt("already mutably borrowed", f) } } /// An error returned by [`AtomicRefCell::try_borrow_mut`](struct.AtomicRefCell.html#method.try_borrow_mut). pub struct BorrowMutError { _private: (), } impl Debug for BorrowMutError { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("BorrowMutError").finish() } } impl Display for BorrowMutError { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { Display::fmt("already borrowed", f) } } impl AtomicRefCell { /// Creates a new `AtomicRefCell` containing `value`. #[inline] pub const fn new(value: T) -> AtomicRefCell { AtomicRefCell { borrow: AtomicUsize::new(0), value: UnsafeCell::new(value), } } /// Consumes the `AtomicRefCell`, returning the wrapped value. #[inline] pub fn into_inner(self) -> T { debug_assert!(self.borrow.load(atomic::Ordering::Acquire) == 0); self.value.into_inner() } } impl AtomicRefCell { /// Immutably borrows the wrapped value. #[inline] pub fn borrow(&self) -> AtomicRef<'_, T> { match AtomicBorrowRef::try_new(&self.borrow) { Ok(borrow) => AtomicRef { value: unsafe { NonNull::new_unchecked(self.value.get()) }, borrow, }, Err(s) => panic!("{}", s), } } /// Attempts to immutably borrow the wrapped value, but instead of panicking /// on a failed borrow, returns `Err`. #[inline] pub fn try_borrow(&self) -> Result, BorrowError> { match AtomicBorrowRef::try_new(&self.borrow) { Ok(borrow) => Ok(AtomicRef { value: unsafe { NonNull::new_unchecked(self.value.get()) }, borrow, }), Err(_) => Err(BorrowError { _private: () }), } } /// Mutably borrows the wrapped value. #[inline] pub fn borrow_mut(&self) -> AtomicRefMut<'_, T> { match AtomicBorrowRefMut::try_new(&self.borrow) { Ok(borrow) => AtomicRefMut { value: unsafe { NonNull::new_unchecked(self.value.get()) }, borrow, marker: PhantomData, }, Err(s) => panic!("{}", s), } } /// Attempts to mutably borrow the wrapped value, but instead of panicking /// on a failed borrow, returns `Err`. #[inline] pub fn try_borrow_mut(&self) -> Result, BorrowMutError> { match AtomicBorrowRefMut::try_new(&self.borrow) { Ok(borrow) => Ok(AtomicRefMut { value: unsafe { NonNull::new_unchecked(self.value.get()) }, borrow, marker: PhantomData, }), Err(_) => Err(BorrowMutError { _private: () }), } } /// Returns a raw pointer to the underlying data in this cell. /// /// External synchronization is needed to avoid data races when dereferencing /// the pointer. #[inline] pub fn as_ptr(&self) -> *mut T { self.value.get() } /// Returns a mutable reference to the wrapped value. /// /// No runtime checks take place (unless debug assertions are enabled) /// because this call borrows `AtomicRefCell` mutably at compile-time. #[inline] pub fn get_mut(&mut self) -> &mut T { debug_assert!(self.borrow.load(atomic::Ordering::Acquire) == 0); unsafe { &mut *self.value.get() } } } // // Core synchronization logic. Keep this section small and easy to audit. // const HIGH_BIT: usize = !(usize::MAX >> 1); const MAX_FAILED_BORROWS: usize = HIGH_BIT + (HIGH_BIT >> 1); struct AtomicBorrowRef<'b> { borrow: &'b AtomicUsize, } impl<'b> AtomicBorrowRef<'b> { #[inline] fn try_new(borrow: &'b AtomicUsize) -> Result { let new = borrow.fetch_add(1, atomic::Ordering::Acquire) + 1; if new & HIGH_BIT != 0 { // If the new count has the high bit set, that almost certainly // means there's an pre-existing mutable borrow. In that case, // we simply leave the increment as a benign side-effect and // return `Err`. Once the mutable borrow is released, the // count will be reset to zero unconditionally. // // The overflow check here ensures that an unbounded number of // immutable borrows during the scope of one mutable borrow // will soundly trigger a panic (or abort) rather than UB. Self::check_overflow(borrow, new); Err("already mutably borrowed") } else { Ok(AtomicBorrowRef { borrow }) } } #[cold] #[inline(never)] fn check_overflow(borrow: &'b AtomicUsize, new: usize) { if new == HIGH_BIT { // We overflowed into the reserved upper half of the refcount // space. Before panicking, decrement the refcount to leave things // in a consistent immutable-borrow state. // // This can basically only happen if somebody forget()s AtomicRefs // in a tight loop. borrow.fetch_sub(1, atomic::Ordering::Release); panic!("too many immutable borrows"); } else if new >= MAX_FAILED_BORROWS { // During the mutable borrow, an absurd number of threads have // attempted to increment the refcount with immutable borrows. // To avoid hypothetically wrapping the refcount, we abort the // process once a certain threshold is reached. // // This requires billions of borrows to fail during the scope of // one mutable borrow, and so is very unlikely to happen in a real // program. // // To avoid a potential unsound state after overflowing, we make // sure the entire process aborts. // // Right now, there's no stable way to do that without `std`: // https://github.com/rust-lang/rust/issues/67952 // As a workaround, we cause an abort by making this thread panic // during the unwinding of another panic. // // On platforms where the panic strategy is already 'abort', the // ForceAbort object here has no effect, as the program already // panics before it is dropped. struct ForceAbort; impl Drop for ForceAbort { fn drop(&mut self) { panic!("Aborting to avoid unsound state of AtomicRefCell"); } } let _abort = ForceAbort; panic!("Too many failed borrows"); } } } impl<'b> Drop for AtomicBorrowRef<'b> { #[inline] fn drop(&mut self) { let old = self.borrow.fetch_sub(1, atomic::Ordering::Release); // This assertion is technically incorrect in the case where another // thread hits the hypothetical overflow case, since we might observe // the refcount before it fixes it up (and panics). But that never will // never happen in a real program, and this is a debug_assert! anyway. debug_assert!(old & HIGH_BIT == 0); } } struct AtomicBorrowRefMut<'b> { borrow: &'b AtomicUsize, } impl<'b> Drop for AtomicBorrowRefMut<'b> { #[inline] fn drop(&mut self) { self.borrow.store(0, atomic::Ordering::Release); } } impl<'b> AtomicBorrowRefMut<'b> { #[inline] fn try_new(borrow: &'b AtomicUsize) -> Result, &'static str> { // Use compare-and-swap to avoid corrupting the immutable borrow count // on illegal mutable borrows. let old = match borrow.compare_exchange( 0, HIGH_BIT, atomic::Ordering::Acquire, atomic::Ordering::Relaxed, ) { Ok(x) => x, Err(x) => x, }; if old == 0 { Ok(AtomicBorrowRefMut { borrow }) } else if old & HIGH_BIT == 0 { Err("already immutably borrowed") } else { Err("already mutably borrowed") } } } unsafe impl Send for AtomicRefCell {} unsafe impl Sync for AtomicRefCell {} // // End of core synchronization logic. No tricky thread stuff allowed below // this point. // impl Clone for AtomicRefCell { #[inline] fn clone(&self) -> AtomicRefCell { AtomicRefCell::new(self.borrow().clone()) } } impl Default for AtomicRefCell { #[inline] fn default() -> AtomicRefCell { AtomicRefCell::new(Default::default()) } } impl PartialEq for AtomicRefCell { #[inline] fn eq(&self, other: &AtomicRefCell) -> bool { *self.borrow() == *other.borrow() } } impl Eq for AtomicRefCell {} impl PartialOrd for AtomicRefCell { #[inline] fn partial_cmp(&self, other: &AtomicRefCell) -> Option { self.borrow().partial_cmp(&*other.borrow()) } } impl Ord for AtomicRefCell { #[inline] fn cmp(&self, other: &AtomicRefCell) -> cmp::Ordering { self.borrow().cmp(&*other.borrow()) } } impl From for AtomicRefCell { fn from(t: T) -> AtomicRefCell { AtomicRefCell::new(t) } } impl<'b> Clone for AtomicBorrowRef<'b> { #[inline] fn clone(&self) -> AtomicBorrowRef<'b> { AtomicBorrowRef::try_new(self.borrow).unwrap() } } /// A wrapper type for an immutably borrowed value from an `AtomicRefCell`. pub struct AtomicRef<'b, T: ?Sized + 'b> { value: NonNull, borrow: AtomicBorrowRef<'b>, } // SAFETY: `AtomicRef<'_, T> acts as a reference. `AtomicBorrowRef` is a // reference to an atomic. unsafe impl<'b, T: ?Sized> Sync for AtomicRef<'b, T> where for<'a> &'a T: Sync {} unsafe impl<'b, T: ?Sized> Send for AtomicRef<'b, T> where for<'a> &'a T: Send {} impl<'b, T: ?Sized> Deref for AtomicRef<'b, T> { type Target = T; #[inline] fn deref(&self) -> &T { // SAFETY: We hold shared borrow of the value. unsafe { self.value.as_ref() } } } impl<'b, T: ?Sized> AtomicRef<'b, T> { /// Copies an `AtomicRef`. /// /// Like its [std-counterpart](core::cell::Ref::clone), this type does not implement `Clone` /// to not interfere with cloning the contained type. #[allow(clippy::should_implement_trait)] #[inline] pub fn clone(orig: &AtomicRef<'b, T>) -> AtomicRef<'b, T> { AtomicRef { value: orig.value, borrow: orig.borrow.clone(), } } /// Make a new `AtomicRef` for a component of the borrowed data. #[inline] pub fn map(orig: AtomicRef<'b, T>, f: F) -> AtomicRef<'b, U> where F: FnOnce(&T) -> &U, { AtomicRef { value: NonNull::from(f(&*orig)), borrow: orig.borrow, } } /// Make a new `AtomicRef` for an optional component of the borrowed data. #[inline] pub fn filter_map(orig: AtomicRef<'b, T>, f: F) -> Option> where F: FnOnce(&T) -> Option<&U>, { Some(AtomicRef { value: NonNull::from(f(&*orig)?), borrow: orig.borrow, }) } } impl<'b, T: ?Sized> AtomicRefMut<'b, T> { /// Make a new `AtomicRefMut` for a component of the borrowed data, e.g. an enum /// variant. #[inline] pub fn map(mut orig: AtomicRefMut<'b, T>, f: F) -> AtomicRefMut<'b, U> where F: FnOnce(&mut T) -> &mut U, { AtomicRefMut { value: NonNull::from(f(&mut *orig)), borrow: orig.borrow, marker: PhantomData, } } /// Make a new `AtomicRefMut` for an optional component of the borrowed data. #[inline] pub fn filter_map( mut orig: AtomicRefMut<'b, T>, f: F, ) -> Option> where F: FnOnce(&mut T) -> Option<&mut U>, { Some(AtomicRefMut { value: NonNull::from(f(&mut *orig)?), borrow: orig.borrow, marker: PhantomData, }) } } /// A wrapper type for a mutably borrowed value from an `AtomicRefCell`. pub struct AtomicRefMut<'b, T: ?Sized + 'b> { value: NonNull, borrow: AtomicBorrowRefMut<'b>, // `NonNull` is covariant over `T`, but this is used in place of a mutable // reference so we need to be invariant over `T`. marker: PhantomData<&'b mut T>, } // SAFETY: `AtomicRefMut<'_, T> acts as a mutable reference. // `AtomicBorrowRefMut` is a reference to an atomic. unsafe impl<'b, T: ?Sized> Sync for AtomicRefMut<'b, T> where for<'a> &'a mut T: Sync {} unsafe impl<'b, T: ?Sized> Send for AtomicRefMut<'b, T> where for<'a> &'a mut T: Send {} impl<'b, T: ?Sized> Deref for AtomicRefMut<'b, T> { type Target = T; #[inline] fn deref(&self) -> &T { // SAFETY: We hold an exclusive borrow of the value. unsafe { self.value.as_ref() } } } impl<'b, T: ?Sized> DerefMut for AtomicRefMut<'b, T> { #[inline] fn deref_mut(&mut self) -> &mut T { // SAFETY: We hold an exclusive borrow of the value. unsafe { self.value.as_mut() } } } impl<'b, T: ?Sized + Debug + 'b> Debug for AtomicRef<'b, T> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { ::fmt(self, f) } } impl<'b, T: ?Sized + Debug + 'b> Debug for AtomicRefMut<'b, T> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { ::fmt(self, f) } } impl Debug for AtomicRefCell { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match self.try_borrow() { Ok(borrow) => f .debug_struct("AtomicRefCell") .field("value", &borrow) .finish(), Err(_) => { // The RefCell is mutably borrowed so we can't look at its value // here. Show a placeholder instead. struct BorrowedPlaceholder; impl Debug for BorrowedPlaceholder { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.write_str("") } } f.debug_struct("AtomicRefCell") .field("value", &BorrowedPlaceholder) .finish() } } } } #[cfg(feature = "serde")] impl<'de, T: Deserialize<'de>> Deserialize<'de> for AtomicRefCell { fn deserialize(deserializer: D) -> Result where D: serde::Deserializer<'de>, { T::deserialize(deserializer).map(Self::from) } } #[cfg(feature = "serde")] impl Serialize for AtomicRefCell { fn serialize(&self, serializer: S) -> Result where S: serde::Serializer, { use serde::ser::Error; match self.try_borrow() { Ok(value) => value.serialize(serializer), Err(_err) => Err(S::Error::custom("already mutably borrowed")), } } } atomic_refcell-0.1.14/tests/async.rs000064400000000000000000000014161046102023000155060ustar 00000000000000use std::future::Future; use atomic_refcell::AtomicRefCell; fn spawn(_future: Fut) where Fut: Future + Send + Sync, { } async fn something_async() {} // see https://github.com/bholley/atomic_refcell/issues/24 #[test] fn test_atomic_ref_in_spawn() { let arc: Box usize + Send + Sync> = Box::new(|| 42); let a = AtomicRefCell::new(arc); spawn(async move { let x = a.borrow(); something_async().await; assert_eq!(x(), 42); }); } #[test] fn test_atomic_ref_mut_in_spawn() { let arc: Box usize + Send + Sync> = Box::new(|| 42); let a = AtomicRefCell::new(arc); spawn(async move { let x = a.borrow_mut(); something_async().await; assert_eq!(x(), 42); }); } atomic_refcell-0.1.14/tests/basic.rs000064400000000000000000000112511046102023000154500ustar 00000000000000use atomic_refcell::{AtomicRef, AtomicRefCell, AtomicRefMut}; #[derive(Debug)] struct Foo { u: u32, } #[derive(Debug)] struct Bar { f: Foo, } impl Default for Bar { fn default() -> Self { Bar { f: Foo { u: 42 } } } } // FIXME(bholley): Add tests to exercise this in concurrent scenarios. #[test] fn immutable() { let a = AtomicRefCell::new(Bar::default()); let _first = a.borrow(); let _second = a.borrow(); } #[test] fn try_immutable() { let a = AtomicRefCell::new(Bar::default()); let _first = a.try_borrow().unwrap(); let _second = a.try_borrow().unwrap(); } #[test] fn mutable() { let a = AtomicRefCell::new(Bar::default()); let _ = a.borrow_mut(); } #[test] fn try_mutable() { let a = AtomicRefCell::new(Bar::default()); let _ = a.try_borrow_mut().unwrap(); } #[test] fn get_mut() { let mut a = AtomicRefCell::new(Bar::default()); let _ = a.get_mut(); } #[test] fn interleaved() { let a = AtomicRefCell::new(Bar::default()); { let _ = a.borrow_mut(); } { let _first = a.borrow(); let _second = a.borrow(); } { let _ = a.borrow_mut(); } } #[test] fn try_interleaved() { let a = AtomicRefCell::new(Bar::default()); { let _ = a.try_borrow_mut().unwrap(); } { let _first = a.try_borrow().unwrap(); let _second = a.try_borrow().unwrap(); let _ = a.try_borrow_mut().unwrap_err(); } { let _first = a.try_borrow_mut().unwrap(); let _ = a.try_borrow().unwrap_err(); } } // For Miri to catch issues when calling a function. // // See how this scenerio affects std::cell::RefCell implementation: // https://github.com/rust-lang/rust/issues/63787 // // Also see relevant unsafe code guidelines issue: // https://github.com/rust-lang/unsafe-code-guidelines/issues/125 #[test] fn drop_and_borrow_in_fn_call() { fn drop_and_borrow(cell: &AtomicRefCell, borrow: AtomicRef<'_, Bar>) { drop(borrow); *cell.borrow_mut() = Bar::default(); } let a = AtomicRefCell::new(Bar::default()); let borrow = a.borrow(); drop_and_borrow(&a, borrow); } #[test] #[should_panic(expected = "already immutably borrowed")] fn immutable_then_mutable() { let a = AtomicRefCell::new(Bar::default()); let _first = a.borrow(); let _second = a.borrow_mut(); } #[test] fn immutable_then_try_mutable() { let a = AtomicRefCell::new(Bar::default()); let _first = a.borrow(); let _second = a.try_borrow_mut().unwrap_err(); } #[test] #[should_panic(expected = "already mutably borrowed")] fn mutable_then_immutable() { let a = AtomicRefCell::new(Bar::default()); let _first = a.borrow_mut(); let _second = a.borrow(); } #[test] fn mutable_then_try_immutable() { let a = AtomicRefCell::new(Bar::default()); let _first = a.borrow_mut(); let _second = a.try_borrow().unwrap_err(); } #[test] #[should_panic(expected = "already mutably borrowed")] fn double_mutable() { let a = AtomicRefCell::new(Bar::default()); let _first = a.borrow_mut(); let _second = a.borrow_mut(); } #[test] fn mutable_then_try_mutable() { let a = AtomicRefCell::new(Bar::default()); let _first = a.borrow_mut(); let _second = a.try_borrow_mut().unwrap_err(); } #[test] fn map() { let a = AtomicRefCell::new(Bar::default()); let b = a.borrow(); assert_eq!(b.f.u, 42); let c = AtomicRef::map(b, |x| &x.f); assert_eq!(c.u, 42); let d = AtomicRef::map(c, |x| &x.u); assert_eq!(*d, 42); } #[test] fn map_mut() { let a = AtomicRefCell::new(Bar::default()); let mut b = a.borrow_mut(); assert_eq!(b.f.u, 42); b.f.u = 43; let mut c = AtomicRefMut::map(b, |x| &mut x.f); assert_eq!(c.u, 43); c.u = 44; let mut d = AtomicRefMut::map(c, |x| &mut x.u); assert_eq!(*d, 44); *d = 45; assert_eq!(*d, 45); } #[test] fn debug_fmt() { let a = AtomicRefCell::new(Foo { u: 42 }); assert_eq!(format!("{:?}", a), "AtomicRefCell { value: Foo { u: 42 } }"); } #[test] fn debug_fmt_borrowed() { let a = AtomicRefCell::new(Foo { u: 42 }); let _b = a.borrow(); assert_eq!(format!("{:?}", a), "AtomicRefCell { value: Foo { u: 42 } }"); } #[test] fn debug_fmt_borrowed_mut() { let a = AtomicRefCell::new(Foo { u: 42 }); let _b = a.borrow_mut(); assert_eq!(format!("{:?}", a), "AtomicRefCell { value: }"); } #[test] #[cfg(feature = "serde")] fn serde() { let value = 10; let cell = AtomicRefCell::new(value); let serialized = serde_json::to_string(&cell).unwrap(); let deserialized = serde_json::from_str::>(&serialized).unwrap(); assert_eq!(*deserialized.borrow(), value); }