Merge pull request #43 from smol-rs/notgull/evl-v3.0.0

Bump to event-listener v3.0.0

.github/workflows/ci.yml

@@ -38,13 +38,18 @@ jobs:
       - name: Install Rust
         run: rustup update ${{ matrix.rust }} && rustup default ${{ matrix.rust }}
       - run: rustup target add wasm32-unknown-unknown
-      - name: Install WASM Test Tools
-        uses: taiki-e/install-action@wasm-pack
+      - name: Install WASM Test Tools and Cargo Hack
+        uses: taiki-e/install-action@v2
+        with:
+          tool: cargo-hack,wasm-pack
       - name: Run cargo check
         run: cargo check --all --all-features --all-targets
+      - run: cargo check --all --no-default-features
       - name: Run cargo check (without dev-dependencies to catch missing feature flags)
         if: startsWith(matrix.rust, 'nightly')
         run: cargo check -Z features=dev_dep
+      - run: rustup target add thumbv7m-none-eabi
+      - run: cargo hack build --all --target thumbv7m-none-eabi --no-default-features --no-dev-deps
       - name: Run cargo check for WASM
         run: cargo check --all --all-features --all-targets --target wasm32-unknown-unknown
       - name: Test WASM
@@ -57,7 +62,7 @@ jobs:
       matrix:
         # When updating this, the reminder to update the minimum supported
         # Rust version in Cargo.toml.
-        rust: ['1.48']
+        rust: ['1.59']
     steps:
       - uses: actions/checkout@v4
       - name: Install Rust

Cargo.toml

@@ -6,7 +6,7 @@ name = "async-lock"
 version = "2.8.0"
 authors = ["Stjepan Glavina <[email protected]>"]
 edition = "2018"
-rust-version = "1.48"
+rust-version = "1.59"
 description = "Async synchronization primitives"
 license = "Apache-2.0 OR MIT"
 repository = "https://github.com/smol-rs/async-lock"
@@ -15,7 +15,13 @@ categories = ["asynchronous", "concurrency"]
 exclude = ["/.*"]
 
 [dependencies]
-event-listener = "2.5.1"
+event-listener = { version = "3.0.0", default-features = false }
+event-listener-strategy = { version = "0.2.0", default-features = false }
+pin-project-lite = "0.2.11"
+
+[features]
+default = ["std"]
+std = ["event-listener/std", "event-listener-strategy/std"]
 
 [dev-dependencies]
 async-channel = "1.5.0"

src/barrier.rs

@@ -1,9 +1,9 @@
 use event_listener::{Event, EventListener};
 
-use std::fmt;
-use std::future::Future;
-use std::pin::Pin;
-use std::task::{Context, Poll};
+use core::fmt;
+use core::future::Future;
+use core::pin::Pin;
+use core::task::{Context, Poll};
 
 use crate::futures::Lock;
 use crate::Mutex;
@@ -82,21 +82,29 @@ impl Barrier {
         BarrierWait {
             barrier: self,
             lock: Some(self.state.lock()),
+            evl: EventListener::new(&self.event),
             state: WaitState::Initial,
         }
     }
 }
 
-/// The future returned by [`Barrier::wait()`].
-pub struct BarrierWait<'a> {
-    /// The barrier to wait on.
-    barrier: &'a Barrier,
+pin_project_lite::pin_project! {
+    /// The future returned by [`Barrier::wait()`].
+    pub struct BarrierWait<'a> {
+        // The barrier to wait on.
+        barrier: &'a Barrier,
 
-    /// The ongoing mutex lock operation we are blocking on.
-    lock: Option<Lock<'a, State>>,
+        // The ongoing mutex lock operation we are blocking on.
+        #[pin]
+        lock: Option<Lock<'a, State>>,
 
-    /// The current state of the future.
-    state: WaitState,
+        // An event listener for the `barrier.event` event.
+        #[pin]
+        evl: EventListener,
+
+        // The current state of the future.
+        state: WaitState,
+    }
 }
 
 impl fmt::Debug for BarrierWait<'_> {
@@ -110,64 +118,61 @@ enum WaitState {
     Initial,
 
     /// We are waiting for the listener to complete.
-    Waiting { evl: EventListener, local_gen: u64 },
+    Waiting { local_gen: u64 },
 
     /// Waiting to re-acquire the lock to check the state again.
-    Reacquiring(u64),
+    Reacquiring { local_gen: u64 },
 }
 
 impl Future for BarrierWait<'_> {
     type Output = BarrierWaitResult;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        let this = self.get_mut();
+        let mut this = self.project();
 
         loop {
             match this.state {
                 WaitState::Initial => {
                     // See if the lock is ready yet.
-                    let mut state = ready!(Pin::new(this.lock.as_mut().unwrap()).poll(cx));
-                    this.lock = None;
+                    let mut state = ready!(this.lock.as_mut().as_pin_mut().unwrap().poll(cx));
+                    this.lock.set(None);
 
                     let local_gen = state.generation_id;
                     state.count += 1;
 
                     if state.count < this.barrier.n {
                         // We need to wait for the event.
-                        this.state = WaitState::Waiting {
-                            evl: this.barrier.event.listen(),
-                            local_gen,
-                        };
+                        this.evl.as_mut().listen();
+                        *this.state = WaitState::Waiting { local_gen };
                     } else {
                         // We are the last one.
                         state.count = 0;
                         state.generation_id = state.generation_id.wrapping_add(1);
-                        this.barrier.event.notify(std::usize::MAX);
+                        this.barrier.event.notify(core::usize::MAX);
                         return Poll::Ready(BarrierWaitResult { is_leader: true });
                     }
                 }
 
-                WaitState::Waiting {
-                    ref mut evl,
-                    local_gen,
-                } => {
-                    ready!(Pin::new(evl).poll(cx));
+                WaitState::Waiting { local_gen } => {
+                    ready!(this.evl.as_mut().poll(cx));
 
                     // We are now re-acquiring the mutex.
-                    this.lock = Some(this.barrier.state.lock());
-                    this.state = WaitState::Reacquiring(local_gen);
+                    this.lock.set(Some(this.barrier.state.lock()));
+                    *this.state = WaitState::Reacquiring {
+                        local_gen: *local_gen,
+                    };
                 }
 
-                WaitState::Reacquiring(local_gen) => {
+                WaitState::Reacquiring { local_gen } => {
                     // Acquire the local state again.
-                    let state = ready!(Pin::new(this.lock.as_mut().unwrap()).poll(cx));
-                    this.lock = None;
+                    let state = ready!(this.lock.as_mut().as_pin_mut().unwrap().poll(cx));
+                    this.lock.set(None);
 
-                    if local_gen == state.generation_id && state.count < this.barrier.n {
+                    if *local_gen == state.generation_id && state.count < this.barrier.n {
                         // We need to wait for the event again.
-                        this.state = WaitState::Waiting {
-                            evl: this.barrier.event.listen(),
-                            local_gen,
+                        this.evl.as_mut().listen();
+                        *this.state = WaitState::Waiting {
+                            local_gen: *local_gen,
                         };
                     } else {
                         // We are ready, but not the leader.

src/lib.rs

@@ -7,6 +7,7 @@
 //! * [`RwLock`] - a reader-writer lock, allowing any number of readers or a single writer.
 //! * [`Semaphore`] - limits the number of concurrent operations.
 
+#![cfg_attr(not(feature = "std"), no_std)]
 #![warn(missing_docs, missing_debug_implementations, rust_2018_idioms)]
 #![doc(
     html_favicon_url = "https://raw.githubusercontent.com/smol-rs/smol/master/assets/images/logo_fullsize_transparent.png"
@@ -15,6 +16,8 @@
     html_logo_url = "https://raw.githubusercontent.com/smol-rs/smol/master/assets/images/logo_fullsize_transparent.png"
 )]
 
+extern crate alloc;
+
 /// Simple macro to extract the value of `Poll` or return `Pending`.
 ///
 /// TODO: Drop in favor of `core::task::ready`, once MSRV is bumped to 1.64.
@@ -38,7 +41,7 @@ macro_rules! pin {
             let mut $x = $x;
             #[allow(unused_mut)]
             let mut $x = unsafe {
-                std::pin::Pin::new_unchecked(&mut $x)
+                core::pin::Pin::new_unchecked(&mut $x)
             };
         )*
     }
@@ -69,3 +72,25 @@ pub mod futures {
     };
     pub use crate::semaphore::{Acquire, AcquireArc};
 }
+
+#[cold]
+fn abort() -> ! {
+    // For no_std targets, panicking while panicking is defined as an abort
+    #[cfg(not(feature = "std"))]
+    {
+        struct Bomb;
+
+        impl Drop for Bomb {
+            fn drop(&mut self) {
+                panic!("Panicking while panicking to abort")
+            }
+        }
+
+        let _bomb = Bomb;
+        panic!("Panicking while panicking to abort")
+    }
+
+    // For libstd targets, abort using std::process::abort
+    #[cfg(feature = "std")]
+    std::process::abort()
+}