From d3c4e4a20a05085eae8d568c7efdbe09bada9cf5 Mon Sep 17 00:00:00 2001 From: Dario Nieuwenhuis Date: Mon, 3 Apr 2023 01:18:27 +0200 Subject: executor: add Pender, rework Cargo features. This introduces a `Pender` struct with enum cases for thread-mode, interrupt-mode and custom callback executors. This avoids calls through function pointers when using only the thread or interrupt executors. Faster, and friendlier to `cargo-call-stack`. `embassy-executor` now has `arch-xxx` Cargo features to select the arch and to enable the builtin executors (thread and interrupt). --- embassy-executor/src/arch/std.rs | 150 ++++++++++++++++++++++----------------- 1 file changed, 83 insertions(+), 67 deletions(-) (limited to 'embassy-executor/src/arch/std.rs') diff --git a/embassy-executor/src/arch/std.rs b/embassy-executor/src/arch/std.rs index 701f0eb18..4e4a178f0 100644 --- a/embassy-executor/src/arch/std.rs +++ b/embassy-executor/src/arch/std.rs @@ -1,84 +1,100 @@ -use std::marker::PhantomData; -use std::sync::{Condvar, Mutex}; +#[cfg(feature = "executor-interrupt")] +compile_error!("`executor-interrupt` is not supported with `arch-std`."); -use super::{raw, Spawner}; +#[cfg(feature = "executor-thread")] +pub use thread::*; +#[cfg(feature = "executor-thread")] +mod thread { + use std::marker::PhantomData; + use std::sync::{Condvar, Mutex}; -/// Single-threaded std-based executor. -pub struct Executor { - inner: raw::Executor, - not_send: PhantomData<*mut ()>, - signaler: &'static Signaler, -} + #[cfg(feature = "nightly")] + pub use embassy_macros::main_std as main; + + use crate::raw::{Pender, PenderInner}; + use crate::{raw, Spawner}; -impl Executor { - /// Create a new Executor. - pub fn new() -> Self { - let signaler = &*Box::leak(Box::new(Signaler::new())); - Self { - inner: raw::Executor::new( - |p| unsafe { - let s = &*(p as *const () as *const Signaler); - s.signal() - }, - signaler as *const _ as _, - ), - not_send: PhantomData, - signaler, + #[derive(Copy, Clone)] + pub(crate) struct ThreadPender(&'static Signaler); + + impl ThreadPender { + #[allow(unused)] + pub(crate) fn pend(self) { + self.0.signal() } } - /// Run the executor. - /// - /// The `init` closure is called with a [`Spawner`] that spawns tasks on - /// this executor. Use it to spawn the initial task(s). After `init` returns, - /// the executor starts running the tasks. - /// - /// To spawn more tasks later, you may keep copies of the [`Spawner`] (it is `Copy`), - /// for example by passing it as an argument to the initial tasks. - /// - /// This function requires `&'static mut self`. This means you have to store the - /// Executor instance in a place where it'll live forever and grants you mutable - /// access. There's a few ways to do this: - /// - /// - a [StaticCell](https://docs.rs/static_cell/latest/static_cell/) (safe) - /// - a `static mut` (unsafe) - /// - a local variable in a function you know never returns (like `fn main() -> !`), upgrading its lifetime with `transmute`. (unsafe) - /// - /// This function never returns. - pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { - init(self.inner.spawner()); + /// Single-threaded std-based executor. + pub struct Executor { + inner: raw::Executor, + not_send: PhantomData<*mut ()>, + signaler: &'static Signaler, + } - loop { - unsafe { self.inner.poll() }; - self.signaler.wait() + impl Executor { + /// Create a new Executor. + pub fn new() -> Self { + let signaler = &*Box::leak(Box::new(Signaler::new())); + Self { + inner: raw::Executor::new(Pender(PenderInner::Thread(ThreadPender(signaler)))), + not_send: PhantomData, + signaler, + } } - } -} -struct Signaler { - mutex: Mutex, - condvar: Condvar, -} + /// Run the executor. + /// + /// The `init` closure is called with a [`Spawner`] that spawns tasks on + /// this executor. Use it to spawn the initial task(s). After `init` returns, + /// the executor starts running the tasks. + /// + /// To spawn more tasks later, you may keep copies of the [`Spawner`] (it is `Copy`), + /// for example by passing it as an argument to the initial tasks. + /// + /// This function requires `&'static mut self`. This means you have to store the + /// Executor instance in a place where it'll live forever and grants you mutable + /// access. There's a few ways to do this: + /// + /// - a [StaticCell](https://docs.rs/static_cell/latest/static_cell/) (safe) + /// - a `static mut` (unsafe) + /// - a local variable in a function you know never returns (like `fn main() -> !`), upgrading its lifetime with `transmute`. (unsafe) + /// + /// This function never returns. + pub fn run(&'static mut self, init: impl FnOnce(Spawner)) -> ! { + init(self.inner.spawner()); -impl Signaler { - fn new() -> Self { - Self { - mutex: Mutex::new(false), - condvar: Condvar::new(), + loop { + unsafe { self.inner.poll() }; + self.signaler.wait() + } } } - fn wait(&self) { - let mut signaled = self.mutex.lock().unwrap(); - while !*signaled { - signaled = self.condvar.wait(signaled).unwrap(); - } - *signaled = false; + struct Signaler { + mutex: Mutex, + condvar: Condvar, } - fn signal(&self) { - let mut signaled = self.mutex.lock().unwrap(); - *signaled = true; - self.condvar.notify_one(); + impl Signaler { + fn new() -> Self { + Self { + mutex: Mutex::new(false), + condvar: Condvar::new(), + } + } + + fn wait(&self) { + let mut signaled = self.mutex.lock().unwrap(); + while !*signaled { + signaled = self.condvar.wait(signaled).unwrap(); + } + *signaled = false; + } + + fn signal(&self) { + let mut signaled = self.mutex.lock().unwrap(); + *signaled = true; + self.condvar.notify_one(); + } } } -- cgit