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github: stjepang

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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

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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

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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 }}

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/target
**/*.rs.bk
Cargo.lock

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# Version 1.0.0
- Initial version

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[package]
name = "async-channel"
version = "1.0.0"
authors = ["Stjepan Glavina <stjepang@gmail.com>"]
edition = "2018"
description = "Async multi-producer multi-consumer channel"
license = "Apache-2.0 OR MIT"
repository = "https://github.com/stjepang/async-channel"
homepage = "https://github.com/stjepang/async-channel"
documentation = "https://docs.rs/async-channel"
keywords = ["mpmc", "mpsc", "spmc", "chan", "futures"]
categories = ["asynchronous", "concurrency"]
readme = "README.md"
[dependencies]
concurrent-queue = "1.0.0"
event-listener = "2.0.0"
futures-core = "0.3.5"
[dev-dependencies]
blocking = "0.4.4"
easy-parallel = "3.0.0"
futures-util = { version = "0.3.5", default-features = false }

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# async-channel
[![Build](https://github.com/stjepang/async-channel/workflows/Build%20and%20test/badge.svg)](
https://github.com/stjepang/async-channel/actions)
[![License](https://img.shields.io/badge/license-MIT%2FApache--2.0-blue.svg)](
https://github.com/stjepang/async-channel)
[![Cargo](https://img.shields.io/crates/v/async-channel.svg)](
https://crates.io/crates/async-channel)
[![Documentation](https://docs.rs/async-channel/badge.svg)](
https://docs.rs/async-channel)
An async multi-producer multi-consumer channel.
There are two kinds of channels:
1. Bounded channel with limited capacity.
2. Unbounded channel with unlimited capacity.
A channel has the `Sender` and `Receiver` side. Both sides are cloneable and can be shared
among multiple threads.
When all `Sender`s or all `Receiver`s are dropped, the channel becomes closed. When a
channel is closed, no more messages can be sent, but remaining messages can still be received.
## Examples
```rust
let (s, r) = async_channel::unbounded();
assert_eq!(s.send("Hello").await, Ok(()));
assert_eq!(r.recv().await, Ok("Hello"));
```
## 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.

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//! An async multi-producer multi-consumer channel.
//!
//! There are two kinds of channels:
//!
//! 1. [Bounded][`bounded()`] channel with limited capacity.
//! 2. [Unbounded][`unbounded()`] channel with unlimited capacity.
//!
//! A channel has the [`Sender`] and [`Receiver`] side. Both sides are cloneable and can be shared
//! among multiple threads.
//!
//! When all [`Sender`]s or all [`Receiver`]s are dropped, the channel becomes closed. When a
//! channel is closed, no more messages can be sent, but remaining messages can still be received.
//!
//! # Examples
//!
//! ```
//! # blocking::block_on! {
//! let (s, r) = async_channel::unbounded();
//!
//! assert_eq!(s.send("Hello").await, Ok(()));
//! assert_eq!(r.recv().await, Ok("Hello"));
//! # }
//! ```
#![warn(missing_docs, missing_debug_implementations, rust_2018_idioms)]
use std::error;
use std::fmt;
use std::future::Future;
use std::pin::Pin;
use std::process;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Arc;
use std::task::{Context, Poll};
use concurrent_queue::{ConcurrentQueue, PopError, PushError};
use event_listener::{Event, EventListener};
use futures_core::stream::Stream;
struct Channel<T> {
/// Inner message queue.
queue: ConcurrentQueue<T>,
/// Send operations waiting while the channel is full.
send_ops: Event,
/// Receive operations waiting while the channel is empty and not closed.
recv_ops: Event,
/// Stream operations while the channel is empty and not closed.
stream_ops: Event,
/// The number of currently active `Sender`s.
sender_count: AtomicUsize,
/// The number of currently active `Receivers`s.
receiver_count: AtomicUsize,
}
impl<T> Channel<T> {
/// Closes the channel and notifies all blocked operations.
fn close(&self) {
if self.queue.close() {
// Notify all send operations.
self.send_ops.notify(usize::MAX);
// Notify all receive and stream operations.
self.recv_ops.notify(usize::MAX);
self.stream_ops.notify(usize::MAX);
}
}
}
/// Creates a bounded channel.
///
/// The created channel has space to hold at most `cap` messages at a time.
///
/// # Panics
///
/// Capacity must be a positive number. If `cap` is zero, this function will panic.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::{bounded, TryRecvError, TrySendError};
///
/// let (s, r) = bounded(1);
///
/// assert_eq!(s.send(10).await, Ok(()));
/// assert_eq!(s.try_send(20), Err(TrySendError::Full(20)));
///
/// assert_eq!(r.recv().await, Ok(10));
/// assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
/// # }
pub fn bounded<T>(cap: usize) -> (Sender<T>, Receiver<T>) {
assert!(cap > 0, "capacity cannot be zero");
let channel = Arc::new(Channel {
queue: ConcurrentQueue::bounded(cap),
send_ops: Event::new(),
recv_ops: Event::new(),
stream_ops: Event::new(),
sender_count: AtomicUsize::new(1),
receiver_count: AtomicUsize::new(1),
});
let s = Sender {
channel: channel.clone(),
};
let r = Receiver {
channel,
listener: None,
};
(s, r)
}
/// Creates an unbounded channel.
///
/// The created channel can hold an unlimited number of messages.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::{unbounded, TryRecvError};
///
/// let (s, r) = unbounded();
///
/// assert_eq!(s.send(10).await, Ok(()));
/// assert_eq!(s.send(20).await, Ok(()));
///
/// assert_eq!(r.recv().await, Ok(10));
/// assert_eq!(r.recv().await, Ok(20));
/// assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
/// # }
pub fn unbounded<T>() -> (Sender<T>, Receiver<T>) {
let channel = Arc::new(Channel {
queue: ConcurrentQueue::unbounded(),
send_ops: Event::new(),
recv_ops: Event::new(),
stream_ops: Event::new(),
sender_count: AtomicUsize::new(1),
receiver_count: AtomicUsize::new(1),
});
let s = Sender {
channel: channel.clone(),
};
let r = Receiver {
channel,
listener: None,
};
(s, r)
}
/// The sending side of a channel.
///
/// Senders can be cloned and shared among threads. When all senders associated with a channel are
/// dropped, the channel becomes closed.
pub struct Sender<T> {
/// Inner channel state.
channel: Arc<Channel<T>>,
}
impl<T> Sender<T> {
/// Attempts to send a message into the channel.
///
/// If the channel is full or closed, this method returns an error.
///
/// # Examples
///
/// ```
/// use async_channel::{bounded, TrySendError};
///
/// let (s, r) = bounded(1);
///
/// assert_eq!(s.try_send(1), Ok(()));
/// assert_eq!(s.try_send(2), Err(TrySendError::Full(2)));
///
/// drop(r);
/// assert_eq!(s.try_send(3), Err(TrySendError::Closed(3)));
/// ```
pub fn try_send(&self, msg: T) -> Result<(), TrySendError<T>> {
match self.channel.queue.push(msg) {
Ok(()) => {
// Notify a single blocked receive operation. If the notified operation then
// receives a message or gets canceled, it will notify another blocked receive
// operation.
self.channel.recv_ops.notify(1);
// Notify all blocked streams.
self.channel.stream_ops.notify(usize::MAX);
Ok(())
}
Err(PushError::Full(msg)) => Err(TrySendError::Full(msg)),
Err(PushError::Closed(msg)) => Err(TrySendError::Closed(msg)),
}
}
/// Sends a message into the channel.
///
/// If the channel is full, this method waits until there is space for a message.
///
/// If the channel is closed, this method returns an error.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::{unbounded, SendError};
///
/// let (s, r) = unbounded();
///
/// assert_eq!(s.send(1).await, Ok(()));
/// drop(r);
/// assert_eq!(s.send(2).await, Err(SendError(2)));
/// # }
/// ```
pub async fn send(&self, msg: T) -> Result<(), SendError<T>> {
let mut listener = None;
let mut msg = msg;
loop {
// Attempt to send a message.
match self.try_send(msg) {
Ok(()) => return Ok(()),
Err(TrySendError::Closed(msg)) => return Err(SendError(msg)),
Err(TrySendError::Full(m)) => msg = m,
}
// Sending failed - now start listening for notifications or wait for one.
match listener.take() {
None => {
// Start listening and then try receiving again.
listener = Some(self.channel.send_ops.listen());
}
Some(l) => {
// Wait for a notification.
l.await;
// If the capacity is larger than 1, notify another blocked send operation.
match self.channel.queue.capacity() {
Some(1) => {}
Some(_) | None => self.channel.send_ops.notify(1),
}
}
}
}
}
/// Returns `true` if the channel is empty.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::unbounded;
///
/// let (s, r) = unbounded();
///
/// assert!(s.is_empty());
/// s.send(1).await;
/// assert!(!s.is_empty());
/// # }
/// ```
pub fn is_empty(&self) -> bool {
self.channel.queue.is_empty()
}
/// Returns `true` if the channel is full.
///
/// Unbounded channels are never full.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::bounded;
///
/// let (s, r) = bounded(1);
///
/// assert!(!s.is_full());
/// s.send(1).await;
/// assert!(s.is_full());
/// # }
/// ```
pub fn is_full(&self) -> bool {
self.channel.queue.is_full()
}
/// Returns the number of messages in the channel.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::unbounded;
///
/// let (s, r) = unbounded();
/// assert_eq!(s.len(), 0);
///
/// s.send(1).await;
/// s.send(2).await;
/// assert_eq!(s.len(), 2);
/// # }
/// ```
pub fn len(&self) -> usize {
self.channel.queue.len()
}
/// Returns the channel capacity if it's bounded.
///
/// # Examples
///
/// ```
/// use async_channel::{bounded, unbounded};
///
/// let (s, r) = bounded::<i32>(5);
/// assert_eq!(s.capacity(), Some(5));
///
/// let (s, r) = unbounded::<i32>();
/// assert_eq!(s.capacity(), None);
/// ```
pub fn capacity(&self) -> Option<usize> {
self.channel.queue.capacity()
}
}
impl<T> Drop for Sender<T> {
fn drop(&mut self) {
// Decrement the sender count and close the channel if it drops down to zero.
if self.channel.sender_count.fetch_sub(1, Ordering::AcqRel) == 1 {
self.channel.close();
}
}
}
impl<T> fmt::Debug for Sender<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "Sender {{ .. }}")
}
}
impl<T> Clone for Sender<T> {
fn clone(&self) -> Sender<T> {
let count = self.channel.sender_count.fetch_add(1, Ordering::Relaxed);
// Make sure the count never overflows, even if lots of sender clones are leaked.
if count > usize::MAX / 2 {
process::abort();
}
Sender {
channel: self.channel.clone(),
}
}
}
/// The receiving side of a channel.
///
/// Receivers can be cloned and shared among threads. When all receivers associated with a channel
/// are dropped, the channel becomes closed.
///
/// Receivers implement the [`Stream`] trait.
pub struct Receiver<T> {
/// Inner channel state.
channel: Arc<Channel<T>>,
/// Listens for a send or close event to unblock this stream.
listener: Option<EventListener>,
}
impl<T> Receiver<T> {
/// Attempts to receive a message from the channel.
///
/// If the channel is empty or closed, this method returns an error.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::{unbounded, TryRecvError};
///
/// let (s, r) = unbounded();
/// assert_eq!(s.send(1).await, Ok(()));
///
/// assert_eq!(r.try_recv(), Ok(1));
/// assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
///
/// drop(s);
/// assert_eq!(r.try_recv(), Err(TryRecvError::Closed));
/// # }
/// ```
pub fn try_recv(&self) -> Result<T, TryRecvError> {
match self.channel.queue.pop() {
Ok(msg) => {
// Notify a single blocked send operation. If the notified operation then sends a
// message or gets canceled, it will notify another blocked send operation.
self.channel.send_ops.notify(1);
Ok(msg)
}
Err(PopError::Empty) => Err(TryRecvError::Empty),
Err(PopError::Closed) => Err(TryRecvError::Closed),
}
}
/// Receives a message from the channel.
///
/// If the channel is empty, this method waits until there is a message.
///
/// If the channel is closed, this method receives a message or returns an error if there are
/// no more messages.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::{unbounded, RecvError};
///
/// let (s, r) = unbounded();
///
/// assert_eq!(s.send(1).await, Ok(()));
/// drop(s);
///
/// assert_eq!(r.recv().await, Ok(1));
/// assert_eq!(r.recv().await, Err(RecvError));
/// # }
/// ```
pub async fn recv(&self) -> Result<T, RecvError> {
let mut listener = None;
loop {
// Attempt to receive a message.
match self.try_recv() {
Ok(msg) => return Ok(msg),
Err(TryRecvError::Closed) => return Err(RecvError),
Err(TryRecvError::Empty) => {}
}
// Receiving failed - now start listening for notifications or wait for one.
match listener.take() {
None => {
// Start listening and then try receiving again.
listener = Some(self.channel.recv_ops.listen());
}
Some(l) => {
// Wait for a notification.
l.await;
// If the capacity is larger than 1, notify another blocked receive operation.
// There is no need to notify stream operations because all of them get
// notified every time a message is sent into the channel.
match self.channel.queue.capacity() {
Some(1) => {}
Some(_) | None => self.channel.recv_ops.notify(1),
}
}
}
}
}
/// Returns `true` if the channel is empty.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::unbounded;
///
/// let (s, r) = unbounded();
///
/// assert!(s.is_empty());
/// s.send(1).await;
/// assert!(!s.is_empty());
/// # }
/// ```
pub fn is_empty(&self) -> bool {
self.channel.queue.is_empty()
}
/// Returns `true` if the channel is full.
///
/// Unbounded channels are never full.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::bounded;
///
/// let (s, r) = bounded(1);
///
/// assert!(!r.is_full());
/// s.send(1).await;
/// assert!(r.is_full());
/// # }
/// ```
pub fn is_full(&self) -> bool {
self.channel.queue.is_full()
}
/// Returns the number of messages in the channel.
///
/// # Examples
///
/// ```
/// # blocking::block_on! {
/// use async_channel::unbounded;
///
/// let (s, r) = unbounded();
/// assert_eq!(r.len(), 0);
///
/// s.send(1).await;
/// s.send(2).await;
/// assert_eq!(r.len(), 2);
/// # }
/// ```
pub fn len(&self) -> usize {
self.channel.queue.len()
}
/// Returns the channel capacity if it's bounded.
///
/// # Examples
///
/// ```
/// use async_channel::{bounded, unbounded};
///
/// let (s, r) = bounded::<i32>(5);
/// assert_eq!(r.capacity(), Some(5));
///
/// let (s, r) = unbounded::<i32>();
/// assert_eq!(r.capacity(), None);
/// ```
pub fn capacity(&self) -> Option<usize> {
self.channel.queue.capacity()
}
}
impl<T> Drop for Receiver<T> {
fn drop(&mut self) {
// Decrement the receiver count and close the channel if it drops down to zero.
if self.channel.receiver_count.fetch_sub(1, Ordering::AcqRel) == 1 {
self.channel.close();
}
}
}
impl<T> fmt::Debug for Receiver<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "Receiver {{ .. }}")
}
}
impl<T> Clone for Receiver<T> {
fn clone(&self) -> Receiver<T> {
let count = self.channel.receiver_count.fetch_add(1, Ordering::Relaxed);
// Make sure the count never overflows, even if lots of receiver clones are leaked.
if count > usize::MAX / 2 {
process::abort();
}
Receiver {
channel: self.channel.clone(),
listener: None,
}
}
}
impl<T> Stream for Receiver<T> {
type Item = T;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
loop {
// If this stream is listening for events, first wait for a notification.
if let Some(listener) = self.listener.as_mut() {
futures_core::ready!(Pin::new(listener).poll(cx));
self.listener = None;
}
loop {
// Attempt to receive a message.
match self.try_recv() {
Ok(msg) => {
// The stream is not blocked on an event - drop the listener.
self.listener = None;
return Poll::Ready(Some(msg));
}
Err(TryRecvError::Closed) => {
// The stream is not blocked on an event - drop the listener.
self.listener = None;
return Poll::Ready(None);
}
Err(TryRecvError::Empty) => {}
}
// Receiving failed - now start listening for notifications or wait for one.
match self.listener.as_mut() {
None => {
// Create a listener and try sending the message again.
self.listener = Some(self.channel.stream_ops.listen());
}
Some(_) => {
// Go back to the outer loop to poll the listener.
break;
}
}
}
}
}
}
/// An error returned from [`Sender::send()`].
///
/// Received because the channel is closed.
#[derive(PartialEq, Eq, Clone, Copy)]
pub struct SendError<T>(pub T);
impl<T> error::Error for SendError<T> {}
impl<T> fmt::Debug for SendError<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "SendError(..)")
}
}
impl<T> fmt::Display for SendError<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "sending into a closed channel")
}
}
/// An error returned from [`Sender::try_send()`].
#[derive(PartialEq, Eq, Clone, Copy)]
pub enum TrySendError<T> {
/// The channel is full but not closed.
Full(T),
/// The channel is closed.
Closed(T),
}
impl<T> error::Error for TrySendError<T> {}
impl<T> fmt::Debug for TrySendError<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
TrySendError::Full(..) => write!(f, "Full(..)"),
TrySendError::Closed(..) => write!(f, "Closed(..)"),
}
}
}
impl<T> fmt::Display for TrySendError<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
TrySendError::Full(..) => write!(f, "sending into a full channel"),
TrySendError::Closed(..) => write!(f, "sending into a closed channel"),
}
}
}
/// An error returned from [`Receiver::recv()`].
///
/// Received because the channel is empty and closed.
#[derive(PartialEq, Eq, Clone, Copy, Debug)]
pub struct RecvError;
impl error::Error for RecvError {}
impl fmt::Display for RecvError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "receiving from an empty and closed channel")
}
}
/// An error returned from [`Receiver::try_recv()`].
#[derive(PartialEq, Eq, Clone, Copy, Debug)]
pub enum TryRecvError {
/// The channel is empty but not closed.
Empty,
/// The channel is empty and closed.
Closed,
}
impl error::Error for TryRecvError {}
impl fmt::Display for TryRecvError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
TryRecvError::Empty => write!(f, "receiving from an empty channel"),
TryRecvError::Closed => write!(f, "receiving from an empty and closed channel"),
}
}
}

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use std::sync::atomic::{AtomicUsize, Ordering};
use std::thread::sleep;
use std::time::Duration;
use async_channel::{bounded, RecvError, SendError, TryRecvError, TrySendError};
use blocking::block_on;
use easy_parallel::Parallel;
use futures_util::stream::StreamExt;
fn ms(ms: u64) -> Duration {
Duration::from_millis(ms)
}
#[test]
fn smoke() {
let (s, r) = bounded(1);
block_on(s.send(7)).unwrap();
assert_eq!(r.try_recv(), Ok(7));
block_on(s.send(8)).unwrap();
assert_eq!(block_on(r.recv()), Ok(8));
assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
}
#[test]
fn capacity() {
for i in 1..10 {
let (s, r) = bounded::<()>(i);
assert_eq!(s.capacity(), Some(i));
assert_eq!(r.capacity(), Some(i));
}
}
#[test]
fn len_empty_full() {
let (s, r) = bounded(2);
assert_eq!(s.len(), 0);
assert_eq!(s.is_empty(), true);
assert_eq!(s.is_full(), false);
assert_eq!(r.len(), 0);
assert_eq!(r.is_empty(), true);
assert_eq!(r.is_full(), false);
block_on(s.send(())).unwrap();
assert_eq!(s.len(), 1);
assert_eq!(s.is_empty(), false);
assert_eq!(s.is_full(), false);
assert_eq!(r.len(), 1);
assert_eq!(r.is_empty(), false);
assert_eq!(r.is_full(), false);
block_on(s.send(())).unwrap();
assert_eq!(s.len(), 2);
assert_eq!(s.is_empty(), false);
assert_eq!(s.is_full(), true);
assert_eq!(r.len(), 2);
assert_eq!(r.is_empty(), false);
assert_eq!(r.is_full(), true);
block_on(r.recv()).unwrap();
assert_eq!(s.len(), 1);
assert_eq!(s.is_empty(), false);
assert_eq!(s.is_full(), false);
assert_eq!(r.len(), 1);
assert_eq!(r.is_empty(), false);
assert_eq!(r.is_full(), false);
}
#[test]
fn try_recv() {
let (s, r) = bounded(100);
Parallel::new()
.add(move || {
assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
sleep(ms(1500));
assert_eq!(r.try_recv(), Ok(7));
sleep(ms(500));
assert_eq!(r.try_recv(), Err(TryRecvError::Closed));
})
.add(move || {
sleep(ms(1000));
block_on(s.send(7)).unwrap();
})
.run();
}
#[test]
fn recv() {
let (s, r) = bounded(100);
Parallel::new()
.add(move || {
assert_eq!(block_on(r.recv()), Ok(7));
sleep(ms(1000));
assert_eq!(block_on(r.recv()), Ok(8));
sleep(ms(1000));
assert_eq!(block_on(r.recv()), Ok(9));
assert_eq!(block_on(r.recv()), Err(RecvError));
})
.add(move || {
sleep(ms(1500));
block_on(s.send(7)).unwrap();
block_on(s.send(8)).unwrap();
block_on(s.send(9)).unwrap();
})
.run();
}
#[test]
fn try_send() {
let (s, r) = bounded(1);
Parallel::new()
.add(move || {
assert_eq!(s.try_send(1), Ok(()));
assert_eq!(s.try_send(2), Err(TrySendError::Full(2)));
sleep(ms(1500));
assert_eq!(s.try_send(3), Ok(()));
sleep(ms(500));
assert_eq!(s.try_send(4), Err(TrySendError::Closed(4)));
})
.add(move || {
sleep(ms(1000));
assert_eq!(r.try_recv(), Ok(1));
assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
assert_eq!(block_on(r.recv()), Ok(3));
})
.run();
}
#[test]
fn send() {
let (s, r) = bounded(1);
Parallel::new()
.add(|| {
block_on(s.send(7)).unwrap();
sleep(ms(1000));
block_on(s.send(8)).unwrap();
sleep(ms(1000));
block_on(s.send(9)).unwrap();
sleep(ms(1000));
block_on(s.send(10)).unwrap();
})
.add(|| {
sleep(ms(1500));
assert_eq!(block_on(r.recv()), Ok(7));
assert_eq!(block_on(r.recv()), Ok(8));
assert_eq!(block_on(r.recv()), Ok(9));
})
.run();
}
#[test]
fn send_after_close() {
let (s, r) = bounded(100);
block_on(s.send(1)).unwrap();
block_on(s.send(2)).unwrap();
block_on(s.send(3)).unwrap();
drop(r);
assert_eq!(block_on(s.send(4)), Err(SendError(4)));
assert_eq!(s.try_send(5), Err(TrySendError::Closed(5)));
assert_eq!(block_on(s.send(6)), Err(SendError(6)));
}
#[test]
fn recv_after_close() {
let (s, r) = bounded(100);
block_on(s.send(1)).unwrap();
block_on(s.send(2)).unwrap();
block_on(s.send(3)).unwrap();
drop(s);
assert_eq!(block_on(r.recv()), Ok(1));
assert_eq!(block_on(r.recv()), Ok(2));
assert_eq!(block_on(r.recv()), Ok(3));
assert_eq!(block_on(r.recv()), Err(RecvError));
}
#[test]
fn len() {
const COUNT: usize = 25_000;
const CAP: usize = 1000;
let (s, r) = bounded(CAP);
assert_eq!(s.len(), 0);
assert_eq!(r.len(), 0);
for _ in 0..CAP / 10 {
for i in 0..50 {
block_on(s.send(i)).unwrap();
assert_eq!(s.len(), i + 1);
}
for i in 0..50 {
block_on(r.recv()).unwrap();
assert_eq!(r.len(), 50 - i - 1);
}
}
assert_eq!(s.len(), 0);
assert_eq!(r.len(), 0);
for i in 0..CAP {
block_on(s.send(i)).unwrap();
assert_eq!(s.len(), i + 1);
}
for _ in 0..CAP {
block_on(r.recv()).unwrap();
}
assert_eq!(s.len(), 0);
assert_eq!(r.len(), 0);
Parallel::new()
.add(|| {
for i in 0..COUNT {
assert_eq!(block_on(r.recv()), Ok(i));
let len = r.len();
assert!(len <= CAP);
}
})
.add(|| {
for i in 0..COUNT {
block_on(s.send(i)).unwrap();
let len = s.len();
assert!(len <= CAP);
}
})
.run();
assert_eq!(s.len(), 0);
assert_eq!(r.len(), 0);
}
#[test]
fn close_wakes_sender() {
let (s, r) = bounded(1);
Parallel::new()
.add(move || {
assert_eq!(block_on(s.send(())), Ok(()));
assert_eq!(block_on(s.send(())), Err(SendError(())));
})
.add(move || {
sleep(ms(1000));
drop(r);
})
.run();
}
#[test]
fn close_wakes_receiver() {
let (s, r) = bounded::<()>(1);
Parallel::new()
.add(move || {
assert_eq!(block_on(r.recv()), Err(RecvError));
})
.add(move || {
sleep(ms(1000));
drop(s);
})
.run();
}
#[test]
fn spsc() {
const COUNT: usize = 100_000;
let (s, r) = bounded(3);
Parallel::new()
.add(move || {
for i in 0..COUNT {
assert_eq!(block_on(r.recv()), Ok(i));
}
assert_eq!(block_on(r.recv()), Err(RecvError));
})
.add(move || {
for i in 0..COUNT {
block_on(s.send(i)).unwrap();
}
})
.run();
}
#[test]
fn mpmc() {
const COUNT: usize = 25_000;
const THREADS: usize = 4;
let (s, r) = bounded::<usize>(3);
let v = (0..COUNT).map(|_| AtomicUsize::new(0)).collect::<Vec<_>>();
Parallel::new()
.each(0..THREADS, |_| {
for _ in 0..COUNT {
let n = block_on(r.recv()).unwrap();
v[n].fetch_add(1, Ordering::SeqCst);
}
})
.each(0..THREADS, |_| {
for i in 0..COUNT {
block_on(s.send(i)).unwrap();
}
})
.run();
for c in v {
assert_eq!(c.load(Ordering::SeqCst), THREADS);
}
}
#[test]
fn mpmc_stream() {
const COUNT: usize = 25_000;
const THREADS: usize = 4;
let (s, r) = bounded::<usize>(3);
let v = (0..COUNT).map(|_| AtomicUsize::new(0)).collect::<Vec<_>>();
let v = &v;
Parallel::new()
.each(0..THREADS, {
let mut r = r.clone();
move |_| {
for _ in 0..COUNT {
let n = block_on(r.next()).unwrap();
v[n].fetch_add(1, Ordering::SeqCst);
}
}
})
.each(0..THREADS, |_| {
for i in 0..COUNT {
block_on(s.send(i)).unwrap();
}
})
.run();
for c in v {
assert_eq!(c.load(Ordering::SeqCst), THREADS);
}
}

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use std::sync::atomic::{AtomicUsize, Ordering};
use std::thread::sleep;
use std::time::Duration;
use async_channel::{unbounded, RecvError, SendError, TryRecvError, TrySendError};
use blocking::block_on;
use easy_parallel::Parallel;
use futures_util::stream::StreamExt;
fn ms(ms: u64) -> Duration {
Duration::from_millis(ms)
}
#[test]
fn smoke() {
let (s, r) = unbounded();
s.try_send(7).unwrap();
assert_eq!(r.try_recv(), Ok(7));
block_on(s.send(8)).unwrap();
assert_eq!(block_on(r.recv()), Ok(8));
assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
}
#[test]
fn capacity() {
let (s, r) = unbounded::<()>();
assert_eq!(s.capacity(), None);
assert_eq!(r.capacity(), None);
}
#[test]
fn len_empty_full() {
let (s, r) = unbounded();
assert_eq!(s.len(), 0);
assert_eq!(s.is_empty(), true);
assert_eq!(s.is_full(), false);
assert_eq!(r.len(), 0);
assert_eq!(r.is_empty(), true);
assert_eq!(r.is_full(), false);
block_on(s.send(())).unwrap();
assert_eq!(s.len(), 1);
assert_eq!(s.is_empty(), false);
assert_eq!(s.is_full(), false);
assert_eq!(r.len(), 1);
assert_eq!(r.is_empty(), false);
assert_eq!(r.is_full(), false);
block_on(r.recv()).unwrap();
assert_eq!(s.len(), 0);
assert_eq!(s.is_empty(), true);
assert_eq!(s.is_full(), false);
assert_eq!(r.len(), 0);
assert_eq!(r.is_empty(), true);
assert_eq!(r.is_full(), false);
}
#[test]
fn try_recv() {
let (s, r) = unbounded();
Parallel::new()
.add(move || {
assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
sleep(ms(1500));
assert_eq!(r.try_recv(), Ok(7));
sleep(ms(500));
assert_eq!(r.try_recv(), Err(TryRecvError::Closed));
})
.add(move || {
sleep(ms(1000));
block_on(s.send(7)).unwrap();
})
.run();
}
#[test]
fn recv() {
let (s, r) = unbounded();
Parallel::new()
.add(move || {
assert_eq!(block_on(r.recv()), Ok(7));
sleep(ms(1000));
assert_eq!(block_on(r.recv()), Ok(8));
sleep(ms(1000));
assert_eq!(block_on(r.recv()), Ok(9));
assert_eq!(block_on(r.recv()), Err(RecvError));
})
.add(move || {
sleep(ms(1500));
block_on(s.send(7)).unwrap();
block_on(s.send(8)).unwrap();
block_on(s.send(9)).unwrap();
})
.run();
}
#[test]
fn try_send() {
let (s, r) = unbounded();
for i in 0..1000 {
assert_eq!(s.try_send(i), Ok(()));
}
drop(r);
assert_eq!(s.try_send(777), Err(TrySendError::Closed(777)));
}
#[test]
fn send() {
let (s, r) = unbounded();
for i in 0..1000 {
assert_eq!(block_on(s.send(i)), Ok(()));
}
drop(r);
assert_eq!(block_on(s.send(777)), Err(SendError(777)));
}
#[test]
fn send_after_close() {
let (s, r) = unbounded();
block_on(s.send(1)).unwrap();
block_on(s.send(2)).unwrap();
block_on(s.send(3)).unwrap();
drop(r);
assert_eq!(block_on(s.send(4)), Err(SendError(4)));
assert_eq!(s.try_send(5), Err(TrySendError::Closed(5)));
}
#[test]
fn recv_after_close() {
let (s, r) = unbounded();
block_on(s.send(1)).unwrap();
block_on(s.send(2)).unwrap();
block_on(s.send(3)).unwrap();
drop(s);
assert_eq!(block_on(r.recv()), Ok(1));
assert_eq!(block_on(r.recv()), Ok(2));
assert_eq!(block_on(r.recv()), Ok(3));
assert_eq!(block_on(r.recv()), Err(RecvError));
}
#[test]
fn len() {
let (s, r) = unbounded();
assert_eq!(s.len(), 0);
assert_eq!(r.len(), 0);
for i in 0..50 {
block_on(s.send(i)).unwrap();
assert_eq!(s.len(), i + 1);
}
for i in 0..50 {
block_on(r.recv()).unwrap();
assert_eq!(r.len(), 50 - i - 1);
}
assert_eq!(s.len(), 0);
assert_eq!(r.len(), 0);
}
#[test]
fn close_wakes_receiver() {
let (s, r) = unbounded::<()>();
Parallel::new()
.add(move || {
assert_eq!(block_on(r.recv()), Err(RecvError));
})
.add(move || {
sleep(ms(1000));
drop(s);
})
.run();
}
#[test]
fn spsc() {
const COUNT: usize = 100_000;
let (s, r) = unbounded();
Parallel::new()
.add(move || {
for i in 0..COUNT {
assert_eq!(block_on(r.recv()), Ok(i));
}
assert_eq!(block_on(r.recv()), Err(RecvError));
})
.add(move || {
for i in 0..COUNT {
block_on(s.send(i)).unwrap();
}
})
.run();
}
#[test]
fn mpmc() {
const COUNT: usize = 25_000;
const THREADS: usize = 4;
let (s, r) = unbounded::<usize>();
let v = (0..COUNT).map(|_| AtomicUsize::new(0)).collect::<Vec<_>>();
Parallel::new()
.each(0..THREADS, |_| {
for _ in 0..COUNT {
let n = block_on(r.recv()).unwrap();
v[n].fetch_add(1, Ordering::SeqCst);
}
})
.each(0..THREADS, |_| {
for i in 0..COUNT {
block_on(s.send(i)).unwrap();
}
})
.run();
assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
for c in v {
assert_eq!(c.load(Ordering::SeqCst), THREADS);
}
}
#[test]
fn mpmc_stream() {
const COUNT: usize = 25_000;
const THREADS: usize = 4;
let (s, r) = unbounded::<usize>();
let v = (0..COUNT).map(|_| AtomicUsize::new(0)).collect::<Vec<_>>();
let v = &v;
Parallel::new()
.each(0..THREADS, {
let mut r = r.clone();
move |_| {
for _ in 0..COUNT {
let n = block_on(r.next()).unwrap();
v[n].fetch_add(1, Ordering::SeqCst);
}
}
})
.each(0..THREADS, |_| {
for i in 0..COUNT {
block_on(s.send(i)).unwrap();
}
})
.run();
assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
for c in v {
assert_eq!(c.load(Ordering::SeqCst), THREADS);
}
}