async-oneshot-0.5.9/.cargo_vcs_info.json0000644000000001120000000000000136320ustar { "git": { "sha1": "1cefbc0ffc98acecb0b71b5566d97833a49f6d47" } } async-oneshot-0.5.9/.gitignore000064400000000000000000000000230000000000000143710ustar 00000000000000/target Cargo.lock async-oneshot-0.5.9/Cargo.toml0000644000000024060000000000000116400ustar # 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 believe there's an error in this file please file an # issue against the rust-lang/cargo repository. If you're # editing this file be aware that the upstream Cargo.toml # will likely look very different (and much more reasonable) [package] edition = "2018" name = "async-oneshot" version = "0.5.9" authors = ["James Laver "] description = "A fast, small, full-featured, async-aware oneshot channel." homepage = "https://github.com/irrustible/async-oneshot" documentation = "https://docs.rs/async-oneshot" readme = "README.md" keywords = ["oneshot", "channel"] categories = ["asynchronous", "concurrency", "data-structures", "no-std"] license = "MPL-2.0" repository = "https://github.com/irrustible/async-oneshot" [[bench]] name = "oneshot" harness = false [dependencies.futures-micro] version = "0.5.0" [dev-dependencies.criterion] version = "0.3" features = ["real_blackbox"] [dev-dependencies.futures-lite] version = "1" [dev-dependencies.waker-fn] version = "1" async-oneshot-0.5.9/Cargo.toml.orig000064400000000000000000000013000000000000000152670ustar 00000000000000[package] name = "async-oneshot" version = "0.5.9" description = "A fast, small, full-featured, async-aware oneshot channel." keywords = ["oneshot", "channel"] categories = ["asynchronous", "concurrency", "data-structures", "no-std"] authors = ["James Laver "] homepage = "https://github.com/irrustible/async-oneshot" repository = "https://github.com/irrustible/async-oneshot" documentation = "https://docs.rs/async-oneshot" license = "MPL-2.0" edition = "2018" readme = "README.md" [dependencies] futures-micro = "0.5.0" [dev-dependencies] futures-lite="1" waker-fn = "1" criterion = { version = "0.3", features = ["real_blackbox"] } [[bench]] name = "oneshot" harness = false async-oneshot-0.5.9/LICENSE000064400000000000000000000405260000000000000134220ustar 00000000000000Mozilla Public License Version 2.0 ================================== 1. Definitions -------------- 1.1. "Contributor" means each individual or legal entity that creates, contributes to the creation of, or owns Covered Software. 1.2. "Contributor Version" means the combination of the Contributions of others (if any) used by a Contributor and that particular Contributor's Contribution. 1.3. "Contribution" means Covered Software of a particular Contributor. 1.4. "Covered Software" means Source Code Form to which the initial Contributor has attached the notice in Exhibit A, the Executable Form of such Source Code Form, and Modifications of such Source Code Form, in each case including portions thereof. 1.5. "Incompatible With Secondary Licenses" means (a) that the initial Contributor has attached the notice described in Exhibit B to the Covered Software; or (b) that the Covered Software was made available under the terms of version 1.1 or earlier of the License, but not also under the terms of a Secondary License. 1.6. "Executable Form" means any form of the work other than Source Code Form. 1.7. "Larger Work" means a work that combines Covered Software with other material, in a separate file or files, that is not Covered Software. 1.8. "License" means this document. 1.9. "Licensable" means having the right to grant, to the maximum extent possible, whether at the time of the initial grant or subsequently, any and all of the rights conveyed by this License. 1.10. "Modifications" means any of the following: (a) any file in Source Code Form that results from an addition to, deletion from, or modification of the contents of Covered Software; or (b) any new file in Source Code Form that contains any Covered Software. 1.11. "Patent Claims" of a Contributor means any patent claim(s), including without limitation, method, process, and apparatus claims, in any patent Licensable by such Contributor that would be infringed, but for the grant of the License, by the making, using, selling, offering for sale, having made, import, or transfer of either its Contributions or its Contributor Version. 1.12. "Secondary License" means either the GNU General Public License, Version 2.0, the GNU Lesser General Public License, Version 2.1, the GNU Affero General Public License, Version 3.0, or any later versions of those licenses. 1.13. "Source Code Form" means the form of the work preferred for making modifications. 1.14. "You" (or "Your") means an individual or a legal entity exercising rights under this License. For legal entities, "You" includes any entity that controls, is controlled by, or is under common control with You. For purposes of this definition, "control" means (a) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (b) ownership of more than fifty percent (50%) of the outstanding shares or beneficial ownership of such entity. 2. License Grants and Conditions -------------------------------- 2.1. Grants Each Contributor hereby grants You a world-wide, royalty-free, non-exclusive license: (a) under intellectual property rights (other than patent or trademark) Licensable by such Contributor to use, reproduce, make available, modify, display, perform, distribute, and otherwise exploit its Contributions, either on an unmodified basis, with Modifications, or as part of a Larger Work; and (b) under Patent Claims of such Contributor to make, use, sell, offer for sale, have made, import, and otherwise transfer either its Contributions or its Contributor Version. 2.2. Effective Date The licenses granted in Section 2.1 with respect to any Contribution become effective for each Contribution on the date the Contributor first distributes such Contribution. 2.3. Limitations on Grant Scope The licenses granted in this Section 2 are the only rights granted under this License. No additional rights or licenses will be implied from the distribution or licensing of Covered Software under this License. Notwithstanding Section 2.1(b) above, no patent license is granted by a Contributor: (a) for any code that a Contributor has removed from Covered Software; or (b) for infringements caused by: (i) Your and any other third party's modifications of Covered Software, or (ii) the combination of its Contributions with other software (except as part of its Contributor Version); or (c) under Patent Claims infringed by Covered Software in the absence of its Contributions. This License does not grant any rights in the trademarks, service marks, or logos of any Contributor (except as may be necessary to comply with the notice requirements in Section 3.4). 2.4. Subsequent Licenses No Contributor makes additional grants as a result of Your choice to distribute the Covered Software under a subsequent version of this License (see Section 10.2) or under the terms of a Secondary License (if permitted under the terms of Section 3.3). 2.5. Representation Each Contributor represents that the Contributor believes its Contributions are its original creation(s) or it has sufficient rights to grant the rights to its Contributions conveyed by this License. 2.6. Fair Use This License is not intended to limit any rights You have under applicable copyright doctrines of fair use, fair dealing, or other equivalents. 2.7. Conditions Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in Section 2.1. 3. Responsibilities ------------------- 3.1. Distribution of Source Form All distribution of Covered Software in Source Code Form, including any Modifications that You create or to which You contribute, must be under the terms of this License. You must inform recipients that the Source Code Form of the Covered Software is governed by the terms of this License, and how they can obtain a copy of this License. You may not attempt to alter or restrict the recipients' rights in the Source Code Form. 3.2. Distribution of Executable Form If You distribute Covered Software in Executable Form then: (a) such Covered Software must also be made available in Source Code Form, as described in Section 3.1, and You must inform recipients of the Executable Form how they can obtain a copy of such Source Code Form by reasonable means in a timely manner, at a charge no more than the cost of distribution to the recipient; and (b) You may distribute such Executable Form under the terms of this License, or sublicense it under different terms, provided that the license for the Executable Form does not attempt to limit or alter the recipients' rights in the Source Code Form under this License. 3.3. Distribution of a Larger Work You may create and distribute a Larger Work under terms of Your choice, provided that You also comply with the requirements of this License for the Covered Software. If the Larger Work is a combination of Covered Software with a work governed by one or more Secondary Licenses, and the Covered Software is not Incompatible With Secondary Licenses, this License permits You to additionally distribute such Covered Software under the terms of such Secondary License(s), so that the recipient of the Larger Work may, at their option, further distribute the Covered Software under the terms of either this License or such Secondary License(s). 3.4. Notices You may not remove or alter the substance of any license notices (including copyright notices, patent notices, disclaimers of warranty, or limitations of liability) contained within the Source Code Form of the Covered Software, except that You may alter any license notices to the extent required to remedy known factual inaccuracies. 3.5. Application of Additional Terms You may choose to offer, and to charge a fee for, warranty, support, indemnity or liability obligations to one or more recipients of Covered Software. However, You may do so only on Your own behalf, and not on behalf of any Contributor. You must make it absolutely clear that any such warranty, support, indemnity, or liability obligation is offered by You alone, and You hereby agree to indemnify every Contributor for any liability incurred by such Contributor as a result of warranty, support, indemnity or liability terms You offer. You may include additional disclaimers of warranty and limitations of liability specific to any jurisdiction. 4. Inability to Comply Due to Statute or Regulation --------------------------------------------------- If it is impossible for You to comply with any of the terms of this License with respect to some or all of the Covered Software due to statute, judicial order, or regulation then You must: (a) comply with the terms of this License to the maximum extent possible; and (b) describe the limitations and the code they affect. Such description must be placed in a text file included with all distributions of the Covered Software under this License. Except to the extent prohibited by statute or regulation, such description must be sufficiently detailed for a recipient of ordinary skill to be able to understand it. 5. Termination -------------- 5.1. The rights granted under this License will terminate automatically if You fail to comply with any of its terms. However, if You become compliant, then the rights granted under this License from a particular Contributor are reinstated (a) provisionally, unless and until such Contributor explicitly and finally terminates Your grants, and (b) on an ongoing basis, if such Contributor fails to notify You of the non-compliance by some reasonable means prior to 60 days after You have come back into compliance. Moreover, Your grants from a particular Contributor are reinstated on an ongoing basis if such Contributor notifies You of the non-compliance by some reasonable means, this is the first time You have received notice of non-compliance with this License from such Contributor, and You become compliant prior to 30 days after Your receipt of the notice. 5.2. If You initiate litigation against any entity by asserting a patent infringement claim (excluding declaratory judgment actions, counter-claims, and cross-claims) alleging that a Contributor Version directly or indirectly infringes any patent, then the rights granted to You by any and all Contributors for the Covered Software under Section 2.1 of this License shall terminate. 5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user license agreements (excluding distributors and resellers) which have been validly granted by You or Your distributors under this License prior to termination shall survive termination. ************************************************************************ * * * 6. Disclaimer of Warranty * * ------------------------- * * * * Covered Software is provided under this License on an "as is" * * basis, without warranty of any kind, either expressed, implied, or * * statutory, including, without limitation, warranties that the * * Covered Software is free of defects, merchantable, fit for a * * particular purpose or non-infringing. The entire risk as to the * * quality and performance of the Covered Software is with You. * * Should any Covered Software prove defective in any respect, You * * (not any Contributor) assume the cost of any necessary servicing, * * repair, or correction. This disclaimer of warranty constitutes an * * essential part of this License. No use of any Covered Software is * * authorized under this License except under this disclaimer. * * * ************************************************************************ ************************************************************************ * * * 7. Limitation of Liability * * -------------------------- * * * * Under no circumstances and under no legal theory, whether tort * * (including negligence), contract, or otherwise, shall any * * Contributor, or anyone who distributes Covered Software as * * permitted above, be liable to You for any direct, indirect, * * special, incidental, or consequential damages of any character * * including, without limitation, damages for lost profits, loss of * * goodwill, work stoppage, computer failure or malfunction, or any * * and all other commercial damages or losses, even if such party * * shall have been informed of the possibility of such damages. This * * limitation of liability shall not apply to liability for death or * * personal injury resulting from such party's negligence to the * * extent applicable law prohibits such limitation. Some * * jurisdictions do not allow the exclusion or limitation of * * incidental or consequential damages, so this exclusion and * * limitation may not apply to You. * * * ************************************************************************ 8. Litigation ------------- Any litigation relating to this License may be brought only in the courts of a jurisdiction where the defendant maintains its principal place of business and such litigation shall be governed by laws of that jurisdiction, without reference to its conflict-of-law provisions. Nothing in this Section shall prevent a party's ability to bring cross-claims or counter-claims. 9. Miscellaneous ---------------- This License represents the complete agreement concerning the subject matter hereof. If any provision of this License is held to be unenforceable, such provision shall be reformed only to the extent necessary to make it enforceable. Any law or regulation which provides that the language of a contract shall be construed against the drafter shall not be used to construe this License against a Contributor. 10. Versions of the License --------------------------- 10.1. New Versions Mozilla Foundation is the license steward. Except as provided in Section 10.3, no one other than the license steward has the right to modify or publish new versions of this License. Each version will be given a distinguishing version number. 10.2. Effect of New Versions You may distribute the Covered Software under the terms of the version of the License under which You originally received the Covered Software, or under the terms of any subsequent version published by the license steward. 10.3. Modified Versions If you create software not governed by this License, and you want to create a new license for such software, you may create and use a modified version of this License if you rename the license and remove any references to the name of the license steward (except to note that such modified license differs from this License). 10.4. Distributing Source Code Form that is Incompatible With Secondary Licenses If You choose to distribute Source Code Form that is Incompatible With Secondary Licenses under the terms of this version of the License, the notice described in Exhibit B of this License must be attached. Exhibit A - Source Code Form License Notice ------------------------------------------- This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/. If it is not possible or desirable to put the notice in a particular file, then You may include the notice in a location (such as a LICENSE file in a relevant directory) where a recipient would be likely to look for such a notice. You may add additional accurate notices of copyright ownership. Exhibit B - "Incompatible With Secondary Licenses" Notice --------------------------------------------------------- This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0. async-oneshot-0.5.9/README.md000064400000000000000000000101520000000000000136640ustar 00000000000000# async-oneshot [![License](https://img.shields.io/crates/l/async-oneshot.svg)](https://github.com/irrustible/async-oneshot/blob/main/LICENSE) [![Package](https://img.shields.io/crates/v/async-oneshot.svg)](https://crates.io/crates/async-oneshot) [![Documentation](https://docs.rs/async-oneshot/badge.svg)](https://docs.rs/async-oneshot) A fast, small, full-featured, async-aware oneshot channel. Features: * Blazing fast! See `Performance` section below. * Tiny code, only one dependency and a lightning quick build. * Complete `no_std` support (with `alloc` for `Arc`). * Unique feature: sender may wait for a receiver to be waiting. ## Usage ```rust #[test] fn success_one_thread() { let (s,r) = oneshot::(); assert_eq!((), s.send(true).unwrap()); assert_eq!(Ok(true), future::block_on(r)); } ``` ## Performance async-oneshot comes with a benchmark suite which you can run with `cargo bench`. All benches are single-threaded and take double digit nanoseconds on my machine. async benches use `futures_lite::future::block_on` as an executor. ### Numbers from my machine Here are benchmark numbers from my primary machine, a Ryzen 9 3900X running alpine linux 3.12 that I attempted to peg at maximum cpu: ``` create_destroy time: [51.596 ns 51.710 ns 51.835 ns] send/success time: [13.080 ns 13.237 ns 13.388 ns] send/closed time: [25.304 ns 25.565 ns 25.839 ns] try_recv/success time: [26.136 ns 26.246 ns 26.335 ns] try_recv/empty time: [10.764 ns 11.161 ns 11.539 ns] try_recv/closed time: [27.048 ns 27.159 ns 27.248 ns] async.recv/success time: [30.532 ns 30.774 ns 31.011 ns] async.recv/closed time: [28.112 ns 28.208 ns 28.287 ns] async.wait/success time: [56.449 ns 56.603 ns 56.737 ns] async.wait/closed time: [34.014 ns 34.154 ns 34.294 ns] ``` In short, we are very fast. Close to optimal, I think. ### Compared to other libraries The oneshot channel in `futures` isn't very fast by comparison. Tokio put up an excellent fight and made us work hard to improve. In general I'd say we're slightly faster overall, but it's incredibly tight. ## Note on safety This crate uses UnsafeCell and manually synchronises with atomic bitwise ops for performance. We believe it is correct, but we would welcome more eyes on it. # See Also * [async-oneshot-local](https://github.com/irrustible/async-oneshot-local) (single threaded) * [async-spsc](https://github.com/irrustible/async-spsc) (SPSC) * [async-channel](https://github.com/stjepang/async-channel) (MPMC) ## Note on benchmarking The benchmarks are synthetic and a bit of fun. ## Changelog ### v0.5.0 Breaking changes: * Make `Sender.send()` only take a mut ref instead of move. ### v0.4.2 Improvements: * Added some tests to cover repeated fix released in last version. * Inline more aggressively for some nice benchmark boosts. ### v0.4.1 Fixes: * Remove some overzealous `debug_assert`s that caused crashes in development in case of repeated waking. Thanks @nazar-pc! Improvements: * Better benchmarks, based on criterion. ### v0.4.0 Breaking changes: * `Sender.wait()`'s function signature has changed to be a non-`async fn` returning an `impl Future`. This reduces binary size, runtime and possibly memory usage too. Thanks @zserik! Fixes: * Race condition where the sender closes in a narrow window during receiver poll and doesn't wake the Receiver. Thanks @zserik! Improvements: * Static assertions. Thanks @zserik! ### v0.3.3 Improvements: * Update `futures-micro` and improve the tests ### v0.3.2 Fixes: * Segfault when dropping receiver. Caused by a typo, d'oh! Thanks @boardwalk! ### v0.3.1 Improvements: * Remove redundant use of ManuallyDrop with UnsafeCell. Thanks @cynecx! ### v0.3.0 Improvements: * Rewrote, benchmarked and optimised. ### v0.2.0 * First real release. ## Copyright and License Copyright (c) 2020 James Laver, async-oneshot contributors. This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/. async-oneshot-0.5.9/benches/oneshot.rs000064400000000000000000000061140000000000000160440ustar 00000000000000use criterion::*; use futures_micro::or; use futures_lite::future::block_on; use async_oneshot::oneshot; pub fn create_destroy(c: &mut Criterion) { c.bench_function( "create_destroy", |b| b.iter(|| oneshot::()) ); } #[allow(unused_must_use)] pub fn send(c: &mut Criterion) { let mut group = c.benchmark_group("send"); group.bench_function( "success", |b| b.iter_batched( || oneshot::(), |(mut send, recv)| { (send.send(1).unwrap(), recv) }, BatchSize::SmallInput ) ); group.bench_function( "closed", |b| b.iter_batched( || oneshot::().0, |mut send| send.send(1).unwrap_err(), BatchSize::SmallInput ) ); } pub fn try_recv(c: &mut Criterion) { let mut group = c.benchmark_group("try_recv"); group.bench_function( "success", |b| b.iter_batched( || { let (mut send, recv) = oneshot::(); send.send(1).unwrap(); recv }, |recv| recv.try_recv().unwrap(), BatchSize::SmallInput ) ); group.bench_function( "empty", |b| b.iter_batched( || oneshot::(), |(send, recv)| (recv.try_recv().unwrap_err(), send), BatchSize::SmallInput ) ); group.bench_function( "closed", |b| b.iter_batched( || oneshot::().1, |recv| recv.try_recv().unwrap_err(), BatchSize::SmallInput ) ); } pub fn recv(c: &mut Criterion) { let mut group = c.benchmark_group("async.recv"); group.bench_function( "success", |b| b.iter_batched( || { let (mut send, recv) = oneshot::(); send.send(42).unwrap(); recv }, |recv| block_on(recv).unwrap(), BatchSize::SmallInput ) ); group.bench_function( "closed", |b| b.iter_batched( || { let (send, recv) = oneshot::(); send.close(); recv }, |recv| block_on(recv).unwrap_err(), BatchSize::SmallInput ) ); } pub fn wait(c: &mut Criterion) { let mut group = c.benchmark_group("async.wait"); group.bench_function( "success", |b| b.iter_batched( || oneshot::(), |(send, recv)| block_on( or!(async { recv.await.unwrap(); 1 }, async { send.wait().await.unwrap(); 2 } ) ), BatchSize::SmallInput ) ); group.bench_function( "closed", |b| b.iter_batched( || oneshot::().0, |send| block_on(send.wait()).unwrap_err(), BatchSize::SmallInput ) ); } criterion_group!( benches , create_destroy , send , try_recv , recv , wait ); criterion_main!(benches); async-oneshot-0.5.9/src/inner.rs000064400000000000000000000072400000000000000146610ustar 00000000000000use core::cell::UnsafeCell; use core::mem::MaybeUninit; use core::ptr::drop_in_place; use core::sync::atomic::{AtomicUsize, Ordering::{Acquire, AcqRel}}; use core::task::Waker; #[derive(Debug)] pub(crate) struct Inner { // This one is easy. state: AtomicUsize, // This is where it all starts to go a bit wrong. value: UnsafeCell>, // Yes, these are subtly different from the last just to confuse you. send: UnsafeCell>, recv: UnsafeCell>, } const CLOSED: usize = 0b1000; const SEND: usize = 0b0100; const RECV: usize = 0b0010; const READY: usize = 0b0001; impl Inner { #[inline(always)] pub(crate) fn new() -> Self { Inner { state: AtomicUsize::new(0), value: UnsafeCell::new(MaybeUninit::uninit()), send: UnsafeCell::new(MaybeUninit::uninit()), recv: UnsafeCell::new(MaybeUninit::uninit()), } } // Gets the current state #[inline(always)] pub(crate) fn state(&self) -> State { State(self.state.load(Acquire)) } // Gets the receiver's waker. You *must* check the state to ensure // it is set. This would be unsafe if it were public. #[inline(always)] pub(crate) fn recv(&self) -> &Waker { // MUST BE SET debug_assert!(self.state().recv()); unsafe { &*(*self.recv.get()).as_ptr() } } // Sets the receiver's waker. #[inline(always)] pub(crate) fn set_recv(&self, waker: Waker) -> State { let recv = self.recv.get(); unsafe { (*recv).as_mut_ptr().write(waker) } // ! State(self.state.fetch_or(RECV, AcqRel)) } // Gets the sender's waker. You *must* check the state to ensure // it is set. This would be unsafe if it were public. #[inline(always)] pub(crate) fn send(&self) -> &Waker { debug_assert!(self.state().send()); unsafe { &*(*self.send.get()).as_ptr() } } // Sets the sender's waker. #[inline(always)] pub(crate) fn set_send(&self, waker: Waker) -> State { let send = self.send.get(); unsafe { (*send).as_mut_ptr().write(waker) } // ! State(self.state.fetch_or(SEND, AcqRel)) } #[inline(always)] pub(crate) fn take_value(&self) -> T { // MUST BE SET debug_assert!(self.state().ready()); unsafe { (*self.value.get()).as_ptr().read() } } #[inline(always)] pub(crate) fn set_value(&self, value: T) -> State { debug_assert!(!self.state().ready()); let val = self.value.get(); unsafe { (*val).as_mut_ptr().write(value) } State(self.state.fetch_or(READY, AcqRel)) } #[inline(always)] pub(crate) fn close(&self) -> State { State(self.state.fetch_or(CLOSED, AcqRel)) } } impl Drop for Inner { #[inline(always)] fn drop(&mut self) { let state = State(*self.state.get_mut()); // Drop the wakers if they are present if state.recv() { unsafe { drop_in_place((&mut *self.recv.get()).as_mut_ptr()); } } if state.send() { unsafe { drop_in_place((&mut *self.send.get()).as_mut_ptr()); } } } } unsafe impl Send for Inner {} unsafe impl Sync for Inner {} #[derive(Clone, Copy)] pub(crate) struct State(usize); impl State { #[inline(always)] pub(crate) fn closed(&self) -> bool { (self.0 & CLOSED) == CLOSED } #[inline(always)] pub(crate) fn ready(&self) -> bool { (self.0 & READY ) == READY } #[inline(always)] pub(crate) fn send(&self) -> bool { (self.0 & SEND ) == SEND } #[inline(always)] pub(crate) fn recv(&self) -> bool { (self.0 & RECV ) == RECV } } async-oneshot-0.5.9/src/lib.rs000064400000000000000000000016270000000000000143170ustar 00000000000000//! A fast, small, full-featured async-aware oneshot channel //! //! Unique feature: wait for receiver to be waiting. //! //! Also supports the full range of things you'd expect. #![no_std] extern crate alloc; use alloc::sync::Arc; mod inner; pub(crate) use inner::Inner; mod sender; pub use sender::Sender; mod receiver; pub use receiver::Receiver; /// Create a new oneshot channel pair. pub fn oneshot() -> (Sender, Receiver) { let inner = Arc::new(Inner::new()); let sender = Sender::new(inner.clone()); let receiver = Receiver::new(inner); (sender, receiver) } /// An empty struct that signifies the channel is closed. #[derive(Clone, Copy, Debug, Eq, PartialEq)] pub struct Closed(); /// We couldn't receive a message. #[derive(Debug)] pub enum TryRecvError { /// The Sender didn't send us a message yet. Empty(Receiver), /// The Sender has dropped. Closed, } async-oneshot-0.5.9/src/receiver.rs000064400000000000000000000042750000000000000153570ustar 00000000000000use crate::*; use core::{future::Future, pin::Pin}; use core::task::{Context, Poll}; /// The receiving half of a oneshot channel. #[derive(Debug)] pub struct Receiver { inner: Arc>, done: bool, } impl Receiver { #[inline(always)] pub(crate) fn new(inner: Arc>) -> Self { Receiver { inner, done: false } } /// Closes the channel by causing an immediate drop. #[inline(always)] pub fn close(self) { } #[inline(always)] fn handle_state(&mut self, state: crate::inner::State) -> Poll> { if state.ready() { Poll::Ready(Ok(self.inner.take_value())) } else if state.closed() { Poll::Ready(Err(Closed())) } else { Poll::Pending }.map(|x| { self.done = true; x }) } /// Attempts to receive. On failure, if the channel is not closed, /// returns self to try again. #[inline] pub fn try_recv(mut self) -> Result> { let state = self.inner.state(); match self.handle_state(state) { Poll::Ready(Ok(x)) => Ok(x), Poll::Ready(Err(Closed())) => Err(TryRecvError::Closed), Poll::Pending => Err(TryRecvError::Empty(self)), } } } impl Future for Receiver { type Output = Result; fn poll(self: Pin<&mut Self>, ctx: &mut Context) -> Poll> { let this = Pin::into_inner(self); match this.handle_state(this.inner.state()) { Poll::Pending => {}, x => return x, } let state = this.inner.set_recv(ctx.waker().clone()); match this.handle_state(state) { Poll::Pending => {}, x => return x, } if state.send() { this.inner.send().wake_by_ref(); } Poll::Pending } } impl Drop for Receiver { #[inline(always)] fn drop(&mut self) { if !self.done { let state = self.inner.state(); if !state.closed() && !state.ready() { let old = self.inner.close(); if old.send() { self.inner.send().wake_by_ref(); } } } } } async-oneshot-0.5.9/src/sender.rs000064400000000000000000000045240000000000000150300ustar 00000000000000use crate::*; use alloc::sync::Arc; use core::{future::Future, task::Poll}; use futures_micro::poll_fn; /// The sending half of a oneshot channel. #[derive(Debug)] pub struct Sender { inner: Arc>, done: bool, } impl Sender { #[inline(always)] pub(crate) fn new(inner: Arc>) -> Self { Sender { inner, done: false } } /// Closes the channel by causing an immediate drop #[inline(always)] pub fn close(self) { } /// true if the channel is closed #[inline(always)] pub fn is_closed(&self) -> bool { self.inner.state().closed() } /// Waits for a Receiver to be waiting for us to send something /// (i.e. allows you to produce a value to send on demand). /// Fails if the Receiver is dropped. #[inline] pub fn wait(self) -> impl Future> { let mut this = Some(self); poll_fn(move |ctx| { let mut that = this.take().unwrap(); let state = that.inner.state(); if state.closed() { that.done = true; Poll::Ready(Err(Closed())) } else if state.recv() { Poll::Ready(Ok(that)) } else { that.inner.set_send(ctx.waker().clone()); this = Some(that); Poll::Pending } }) } /// Sends a message on the channel. Fails if the Receiver is dropped. #[inline] pub fn send(&mut self, value: T) -> Result<(), Closed> { if self.done { Err(Closed()) } else { self.done = true; let inner = &mut self.inner; let state = inner.set_value(value); if !state.closed() { if state.recv() { inner.recv().wake_by_ref(); Ok(()) } else { Ok(()) } } else { inner.take_value(); // force drop. Err(Closed()) } } } } impl Drop for Sender { #[inline(always)] fn drop(&mut self) { if !self.done { let state = self.inner.state(); if !state.closed() { let old = self.inner.close(); if old.recv() { self.inner.recv().wake_by_ref(); } } } } } async-oneshot-0.5.9/tests/test.rs000064400000000000000000000045360000000000000151050ustar 00000000000000use async_oneshot::*; use futures_lite::future::block_on; use futures_micro::prelude::*; use waker_fn::waker_fn; #[test] fn send_recv() { let (mut s,r) = oneshot::(); assert_eq!( block_on(zip!(async { s.send(42).unwrap() }, r)), ((), Ok(42)) ) } #[test] fn recv_send() { let (mut s,r) = oneshot::(); assert_eq!( block_on(zip!(r, async { s.send(42).unwrap() })), (Ok(42), ()) ) } #[test] fn recv_recv() { let (_s, mut r) = oneshot::(); let waker = waker_fn(|| ()); let mut ctx = Context::from_waker(&waker); assert_eq!(Receiver::poll(Pin::new(&mut r), &mut ctx), Poll::Pending); assert_eq!(Receiver::poll(Pin::new(&mut r), &mut ctx), Poll::Pending); } #[test] fn close_recv() { let (s,r) = oneshot::(); s.close(); assert_eq!(Err(Closed()), block_on(r)); } #[test] fn close_send() { let (mut s,r) = oneshot::(); r.close(); assert_eq!(Err(Closed()), s.send(true)); } #[test] fn send_close() { let (mut s,r) = oneshot::(); s.send(true).unwrap(); r.close(); } #[test] fn recv_close() { let (s,r) = oneshot::(); assert_eq!( block_on(zip!(r, async { s.close() })), (Err(Closed()), ()) ) } #[test] fn wait_close() { let (s,r) = oneshot::(); assert_eq!( block_on( zip!(async { s.wait().await.unwrap_err() }, async { r.close() }) ), (Closed(), ()) ) } #[test] fn wait_wait() { let (s, _r) = oneshot::(); let waker = waker_fn(|| ()); let mut ctx = Context::from_waker(&waker); let mut wait = s.wait(); assert!(Future::poll(Pin::new(&mut wait), &mut ctx).is_pending()); assert!(Future::poll(Pin::new(&mut wait), &mut ctx).is_pending()); } #[test] fn wait_recv_close() { let (s,r) = oneshot::(); assert_eq!( block_on( zip!(async { s.wait().await.unwrap().close(); println!("closed"); }, r) ), ((), Err(Closed())) ) } #[test] fn wait_recv_send() { let (s,r) = oneshot::(); assert_eq!( block_on( zip!(async { let mut s = s.wait().await?; s.send(42) }, r) ), (Ok(()), Ok(42)) ) } #[test] fn close_wait() { let (s,r) = oneshot::(); r.close(); assert_eq!(Closed(), block_on(s.wait()).unwrap_err()); }