From e41f34cc003881751db93b8ab6b19d6caeffdf5a Mon Sep 17 00:00:00 2001 From: Stjepan Glavina Date: Thu, 23 Jul 2020 12:03:03 +0200 Subject: [PATCH] Initial commit --- .github/FUNDING.yml | 1 + .github/workflows/build-and-test.yaml | 51 +++ .github/workflows/lint.yaml | 26 ++ .github/workflows/security.yaml | 20 ++ .gitignore | 2 + CHANGELOG.md | 3 + Cargo.toml | 32 ++ LICENSE-APACHE | 201 ++++++++++++ LICENSE-MIT | 23 ++ README.md | 52 +++ rustfmt.toml | 1 + src/lib.rs | 452 ++++++++++++++++++++++++++ 12 files changed, 864 insertions(+) create mode 100644 .github/FUNDING.yml create mode 100644 .github/workflows/build-and-test.yaml create mode 100644 .github/workflows/lint.yaml create mode 100644 .github/workflows/security.yaml create mode 100644 .gitignore create mode 100644 CHANGELOG.md create mode 100644 Cargo.toml create mode 100644 LICENSE-APACHE create mode 100644 LICENSE-MIT create mode 100644 README.md create mode 100644 rustfmt.toml create mode 100644 src/lib.rs diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml new file mode 100644 index 0000000..e1f75e7 --- /dev/null +++ b/.github/FUNDING.yml @@ -0,0 +1 @@ +github: stjepang diff --git a/.github/workflows/build-and-test.yaml b/.github/workflows/build-and-test.yaml new file mode 100644 index 0000000..19d1ebb --- /dev/null +++ b/.github/workflows/build-and-test.yaml @@ -0,0 +1,51 @@ +name: Build and test + +on: + push: + branches: + - master + pull_request: + +jobs: + build_and_test: + runs-on: ${{ matrix.os }} + strategy: + fail-fast: false + matrix: + os: [ubuntu-latest] + rust: [nightly, beta, stable] + steps: + - uses: actions/checkout@v2 + + - name: Set current week of the year in environnement + if: startsWith(matrix.os, 'ubuntu') || startsWith(matrix.os, 'macOS') + run: echo "::set-env name=CURRENT_WEEK::$(date +%V)" + + - name: Set current week of the year in environnement + if: startsWith(matrix.os, 'windows') + run: echo "::set-env name=CURRENT_WEEK::$(Get-Date -UFormat %V)" + + - name: Install latest ${{ matrix.rust }} + uses: actions-rs/toolchain@v1 + with: + toolchain: ${{ matrix.rust }} + profile: minimal + override: true + + - name: Run cargo check + uses: actions-rs/cargo@v1 + with: + command: check + args: --all --bins --examples --tests --all-features + + - name: Run cargo check (without dev-dependencies to catch missing feature flags) + if: startsWith(matrix.rust, 'nightly') + uses: actions-rs/cargo@v1 + with: + command: check + args: -Z features=dev_dep + + - name: Run cargo test + uses: actions-rs/cargo@v1 + with: + command: test diff --git a/.github/workflows/lint.yaml b/.github/workflows/lint.yaml new file mode 100644 index 0000000..7e9bd98 --- /dev/null +++ b/.github/workflows/lint.yaml @@ -0,0 +1,26 @@ +name: Lint + +on: + push: + branches: + - master + pull_request: + +jobs: + clippy: + runs-on: ubuntu-latest + steps: + - uses: actions/checkout@v2 + + - name: Set current week of the year in environnement + run: echo "::set-env name=CURRENT_WEEK::$(date +%V)" + + - uses: actions-rs/toolchain@v1 + with: + toolchain: stable + profile: minimal + components: clippy + - uses: actions-rs/clippy-check@v1 + with: + token: ${{ secrets.GITHUB_TOKEN }} + args: --all-features -- -W clippy::all diff --git a/.github/workflows/security.yaml b/.github/workflows/security.yaml new file mode 100644 index 0000000..8f722e7 --- /dev/null +++ b/.github/workflows/security.yaml @@ -0,0 +1,20 @@ +name: Security audit + +on: + push: + branches: + - master + pull_request: + +jobs: + security_audit: + runs-on: ubuntu-latest + steps: + - uses: actions/checkout@v2 + + - name: Set current week of the year in environnement + run: echo "::set-env name=CURRENT_WEEK::$(date +%V)" + + - uses: actions-rs/audit-check@v1 + with: + token: ${{ secrets.GITHUB_TOKEN }} diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..96ef6c0 --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +/target +Cargo.lock diff --git a/CHANGELOG.md b/CHANGELOG.md new file mode 100644 index 0000000..ad9e8a3 --- /dev/null +++ b/CHANGELOG.md @@ -0,0 +1,3 @@ +# Version 0.1.1 + +- Initial version diff --git a/Cargo.toml b/Cargo.toml new file mode 100644 index 0000000..56da213 --- /dev/null +++ b/Cargo.toml @@ -0,0 +1,32 @@ +[package] +name = "async-executor" +version = "0.1.0" +authors = ["Stjepan Glavina "] +edition = "2018" +description = "Async executor" +license = "Apache-2.0 OR MIT" +repository = "https://github.com/stjepang/async-executor" +homepage = "https://github.com/stjepang/async-executor" +documentation = "https://docs.rs/async-executor" +keywords = ["asynchronous", "executor", "single", "multi", "spawn"] +categories = ["asynchronous", "concurrency"] +readme = "README.md" + +[features] +default = ["async-io"] + +[dependencies] +futures-lite = "0.1.8" +multitask = "0.2.0" +parking = "1.0.5" +scoped-tls = "1.0.0" +waker-fn = "1.0.0" + +# Optional optimization: executor waits on I/O when idle. +[dependencies.async-io] +version = "0.1.5" +optional = true + +[dev-dependencies] +async-channel = "1.1.1" +easy-parallel = "3.1.0" diff --git a/LICENSE-APACHE b/LICENSE-APACHE new file mode 100644 index 0000000..16fe87b --- /dev/null +++ b/LICENSE-APACHE @@ -0,0 +1,201 @@ + 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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IN NO EVENT +SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR +IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +DEALINGS IN THE SOFTWARE. diff --git a/README.md b/README.md new file mode 100644 index 0000000..9c1e68d --- /dev/null +++ b/README.md @@ -0,0 +1,52 @@ +# async-executor + +[![Build](https://github.com/stjepang/async-executor/workflows/Build%20and%20test/badge.svg)]( +https://github.com/stjepang/async-executor/actions) +[![License](https://img.shields.io/badge/license-MIT%2FApache--2.0-blue.svg)]( +https://github.com/stjepang/async-executor) +[![Cargo](https://img.shields.io/crates/v/async-executor.svg)]( +https://crates.io/crates/async-executor) +[![Documentation](https://docs.rs/async-executor/badge.svg)]( +https://docs.rs/async-executor) + +Async executor. + +This crate offers two kinds of executors: single-threaded and multi-threaded. + +## Examples + +Run a single-threaded and a multi-threaded executor at the same time: + +```rust +use async_channel::unbounded; +use async_executor::{Executor, LocalExecutor}; +use easy_parallel::Parallel; + +let ex = Executor::new(); +let local_ex = LocalExecutor::new(); +let (trigger, shutdown) = unbounded::<()>(); + +Parallel::new() + // Run four executor threads. + .each(0..4, |_| ex.run(shutdown.recv())) + // Run local executor on the current thread. + .finish(|| local_ex.run(async { + println!("Hello world!"); + drop(trigger); + })); +``` + +## License + +Licensed under either of + + * Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) + * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) + +at your option. + +#### Contribution + +Unless you explicitly state otherwise, any contribution intentionally submitted +for inclusion in the work by you, as defined in the Apache-2.0 license, shall be +dual licensed as above, without any additional terms or conditions. diff --git a/rustfmt.toml b/rustfmt.toml new file mode 100644 index 0000000..1082fd8 --- /dev/null +++ b/rustfmt.toml @@ -0,0 +1 @@ +version = "Two" diff --git a/src/lib.rs b/src/lib.rs new file mode 100644 index 0000000..cf29f08 --- /dev/null +++ b/src/lib.rs @@ -0,0 +1,452 @@ +//! Async executor. +//! +//! This crate offers two kinds of executors: single-threaded and multi-threaded. +//! +//! # Examples +//! +//! Run a single-threaded and a multi-threaded executor at the same time: +//! +//! ``` +//! use async_channel::unbounded; +//! use async_executor::{Executor, LocalExecutor}; +//! use easy_parallel::Parallel; +//! +//! let ex = Executor::new(); +//! let local_ex = LocalExecutor::new(); +//! let (trigger, shutdown) = unbounded::<()>(); +//! +//! Parallel::new() +//! // Run four executor threads. +//! .each(0..4, |_| ex.run(shutdown.recv())) +//! // Run local executor on the current thread. +//! .finish(|| local_ex.run(async { +//! println!("Hello world!"); +//! drop(trigger); +//! })); +//! ``` + +#![forbid(unsafe_code)] +#![warn(missing_docs, missing_debug_implementations, rust_2018_idioms)] + +use std::future::Future; +use std::pin::Pin; +use std::task::{Context, Poll}; +use std::time::Duration; + +use futures_lite::pin; +use scoped_tls::scoped_thread_local; +use waker_fn::waker_fn; + +#[cfg(feature = "async-io")] +use async_io::parking; +#[cfg(not(feature = "async-io"))] +use parking; + +scoped_thread_local!(static EX: Executor); +scoped_thread_local!(static LOCAL_EX: LocalExecutor); + +/// Multi-threaded executor. +/// +/// The executor does not spawn threads on its own. Instead, you need to call [`Executor::run()`] +/// on manually spawned executor threads. +/// +/// # Examples +/// +/// ``` +/// use async_channel::unbounded; +/// use async_executor::Executor; +/// use easy_parallel::Parallel; +/// use futures_lite::future; +/// +/// let ex = Executor::new(); +/// let (signal, shutdown) = unbounded::<()>(); +/// +/// Parallel::new() +/// // Run four executor threads. +/// .each(0..4, |_| ex.run(shutdown.recv())) +/// // Run the main future on the current thread. +/// .finish(|| future::block_on(async { +/// println!("Hello world!"); +/// drop(signal); +/// })); +/// ``` +#[derive(Debug)] +pub struct Executor { + ex: multitask::Executor, +} + +impl Executor { + /// Creates a multi-threaded executor. + /// + /// # Examples + /// + /// ``` + /// use async_executor::LocalExecutor; + /// + /// let local_ex = LocalExecutor::new(); + /// ``` + pub fn new() -> Executor { + Executor { + ex: multitask::Executor::new(), + } + } + + /// Spawns a task onto the executor. + /// + /// # Examples + /// + /// ``` + /// use async_executor::Executor; + /// + /// let ex = Executor::new(); + /// + /// let task = ex.spawn(async { + /// println!("Hello world"); + /// }); + /// ``` + pub fn spawn( + &self, + future: impl Future + Send + 'static, + ) -> Task { + Task(self.ex.spawn(future)) + } + + /// Enters the context of an executor. + /// + /// # Examples + /// + /// ``` + /// use async_executor::{Executor, Task}; + /// + /// let ex = Executor::new(); + /// + /// ex.enter(|| { + /// // `Task::spawn()` now knows which executor to spawn onto. + /// let task = Task::spawn(async { + /// println!("Hello world"); + /// }); + /// }); + /// ``` + pub fn enter(&self, f: impl FnOnce() -> T) -> T { + if EX.is_set() { + panic!("cannot call `Executor::enter()` if already inside an `Executor`"); + } + EX.set(self, f) + } + + /// Runs the executor until the given future completes. + /// + /// # Examples + /// + /// ``` + /// use async_executor::Executor; + /// + /// let ex = Executor::new(); + /// + /// let task = ex.spawn(async { 1 + 2 }); + /// let res = ex.run(async { task.await * 2 }); + /// + /// assert_eq!(res, 6); + /// ``` + pub fn run(&self, future: impl Future) -> T { + self.enter(|| { + let (p, u) = parking::pair(); + + let ticker = self.ex.ticker({ + let u = u.clone(); + move || u.unpark() + }); + + pin!(future); + let waker = waker_fn(move || u.unpark()); + let cx = &mut Context::from_waker(&waker); + + 'start: loop { + if let Poll::Ready(t) = future.as_mut().poll(cx) { + break t; + } + + for _ in 0..200 { + if !ticker.tick() { + p.park(); + continue 'start; + } + } + p.park_timeout(Duration::from_secs(0)); + } + }) + } +} + +impl Default for Executor { + fn default() -> Executor { + Executor::new() + } +} + +/// Single-threaded executor. +/// +/// The executor can only be run on the thread that created it. +/// +/// # Examples +/// +/// ``` +/// use async_executor::LocalExecutor; +/// +/// let local_ex = LocalExecutor::new(); +/// +/// local_ex.run(async { +/// println!("Hello world!"); +/// }); +/// ``` +#[derive(Debug)] +pub struct LocalExecutor { + ex: multitask::LocalExecutor, + parker: parking::Parker, +} + +impl LocalExecutor { + /// Creates a single-threaded executor. + /// + /// # Examples + /// + /// ``` + /// use async_executor::LocalExecutor; + /// + /// let local_ex = LocalExecutor::new(); + /// ``` + pub fn new() -> LocalExecutor { + let (p, u) = parking::pair(); + LocalExecutor { + ex: multitask::LocalExecutor::new(move || u.unpark()), + parker: p, + } + } + + /// Spawns a task onto the executor. + /// + /// # Examples + /// + /// ``` + /// use async_executor::LocalExecutor; + /// + /// let local_ex = LocalExecutor::new(); + /// + /// let task = local_ex.spawn(async { + /// println!("Hello world"); + /// }); + /// ``` + pub fn spawn(&self, future: impl Future + 'static) -> Task { + Task(self.ex.spawn(future)) + } + + /// Runs the executor until the given future completes. + /// + /// # Examples + /// + /// ``` + /// use async_executor::LocalExecutor; + /// + /// let local_ex = LocalExecutor::new(); + /// + /// let task = local_ex.spawn(async { 1 + 2 }); + /// let res = local_ex.run(async { task.await * 2 }); + /// + /// assert_eq!(res, 6); + /// ``` + pub fn run(&self, future: impl Future) -> T { + pin!(future); + + let u = self.parker.unparker(); + let waker = waker_fn(move || u.unpark()); + let cx = &mut Context::from_waker(&waker); + + LOCAL_EX.set(self, || { + 'start: loop { + if let Poll::Ready(t) = future.as_mut().poll(cx) { + break t; + } + + for _ in 0..200 { + if !self.ex.tick() { + self.parker.park(); + continue 'start; + } + } + self.parker.park_timeout(Duration::from_secs(0)); + } + }) + } +} + +impl Default for LocalExecutor { + fn default() -> LocalExecutor { + LocalExecutor::new() + } +} + +/// A spawned future. +/// +/// Tasks are also futures themselves and yield the output of the spawned future. +/// +/// When a task is dropped, its gets canceled and won't be polled again. To cancel a task a bit +/// more gracefully and wait until it stops running, use the [`cancel()`][`Task::cancel()`] method. +/// +/// Tasks that panic get immediately canceled. Awaiting a canceled task also causes a panic. +/// +/// # Examples +/// +/// ``` +/// use async_executor::{Executor, Task}; +/// +/// let ex = Executor::new(); +/// +/// ex.run(async { +/// let task = Task::spawn(async { +/// println!("Hello from a task!"); +/// 1 + 2 +/// }); +/// +/// assert_eq!(task.await, 3); +/// }); +/// ``` +#[must_use = "tasks get canceled when dropped, use `.detach()` to run them in the background"] +#[derive(Debug)] +pub struct Task(multitask::Task); + +impl Task { + /// Spawns a task onto the current multi-threaded or single-threaded executor. + /// + /// If called from an [`Executor`] (preferred) or from a [`LocalExecutor`], the task is spawned + /// on it. + /// + /// Otherwise, this method panics. + /// + /// # Examples + /// + /// ``` + /// use async_executor::{Executor, Task}; + /// + /// let ex = Executor::new(); + /// + /// ex.run(async { + /// let task = Task::spawn(async { 1 + 2 }); + /// assert_eq!(task.await, 3); + /// }); + /// ``` + /// + /// ``` + /// use async_executor::{LocalExecutor, Task}; + /// + /// let local_ex = LocalExecutor::new(); + /// + /// local_ex.run(async { + /// let task = Task::spawn(async { 1 + 2 }); + /// assert_eq!(task.await, 3); + /// }); + /// ``` + pub fn spawn(future: impl Future + Send + 'static) -> Task + where + T: Send + 'static, + { + if EX.is_set() { + EX.with(|ex| ex.spawn(future)) + } else if LOCAL_EX.is_set() { + LOCAL_EX.with(|local_ex| local_ex.spawn(future)) + } else { + panic!("`Task::spawn()` must be called from an `Executor` or `LocalExecutor`") + } + } + + /// Spawns a task onto the current single-threaded executor. + /// + /// If called from a [`LocalExecutor`], the task is spawned on it. + /// + /// Otherwise, this method panics. + /// + /// # Examples + /// + /// ``` + /// use async_executor::{LocalExecutor, Task}; + /// + /// let local_ex = LocalExecutor::new(); + /// + /// local_ex.run(async { + /// let task = Task::local(async { 1 + 2 }); + /// assert_eq!(task.await, 3); + /// }); + /// ``` + pub fn local(future: impl Future + 'static) -> Task + where + T: 'static, + { + if LOCAL_EX.is_set() { + LOCAL_EX.with(|local_ex| local_ex.spawn(future)) + } else { + panic!("`Task::local()` must be called from a `LocalExecutor`") + } + } + + /// Detaches the task to let it keep running in the background. + /// + /// # Examples + /// + /// ``` + /// use async_executor::{Executor, Task}; + /// use futures_lite::future; + /// + /// let ex = Executor::new(); + /// + /// ex.spawn(async { + /// loop { + /// println!("I'm a background task looping forever."); + /// future::yield_now().await; + /// } + /// }) + /// .detach(); + /// + /// ex.run(future::yield_now()); + /// ``` + pub fn detach(self) { + self.0.detach(); + } + + /// Cancels the task and waits for it to stop running. + /// + /// Returns the task's output if it was completed just before it got canceled, or [`None`] if + /// it didn't complete. + /// + /// While it's possible to simply drop the [`Task`] to cancel it, this is a cleaner way of + /// canceling because it also waits for the task to stop running. + /// + /// # Examples + /// + /// ``` + /// use async_executor::{Executor, Task}; + /// use futures_lite::future; + /// + /// let ex = Executor::new(); + /// + /// let task = ex.spawn(async { + /// loop { + /// println!("Even though I'm in an infinite loop, you can still cancel me!"); + /// future::yield_now().await; + /// } + /// }); + /// + /// ex.run(async { + /// task.cancel().await; + /// }); + /// ``` + pub async fn cancel(self) -> Option { + self.0.cancel().await + } +} + +impl Future for Task { + type Output = T; + + fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll { + Pin::new(&mut self.0).poll(cx) + } +}