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#[cfg(any(test, feature = "coop"))]
mod coop_impl {
use crate::coop::Operation;
use tokio::sync::mpsc;
pub use mpsc::error;
pub struct Sender<T> {
send_op: Operation,
inner: mpsc::Sender<T>,
}
pub struct Receiver<T> {
recv_op: Operation,
inner: mpsc::Receiver<T>,
}
pub struct UnboundedSender<T> {
send_op: Operation,
inner: mpsc::UnboundedSender<T>,
}
pub struct UnboundedReceiver<T> {
recv_op: Operation,
inner: mpsc::UnboundedReceiver<T>,
}
pub struct WeakSender<T> {
send_op: Operation,
inner: mpsc::WeakSender<T>,
}
pub struct WeakUnboundedSender<T> {
send_op: Operation,
inner: mpsc::WeakUnboundedSender<T>,
}
pub struct Permit<'a, T> {
inner: mpsc::Permit<'a, T>,
}
pub struct OwnedPermit<T> {
inner: mpsc::OwnedPermit<T>,
send_op: Operation,
}
pub struct PermitIterator<'a, T> {
inner: mpsc::PermitIterator<'a, T>,
}
impl<T> Sender<T> {
/// Sends a value, waiting until there is capacity.
pub async fn send(&self, value: T) -> Result<(), error::SendError<T>> {
use crate::tracing::Instrument;
let span = crate::tracing::debug_span!("mpsc::send");
async {
// First acquire the operation through the coop system
self.send_op.acquire().await;
// Then perform the actual send
self.inner.send(value).await
}
.instrument(span)
.await
}
/// Tries to send a value immediately.
pub fn try_send(&self, value: T) -> Result<(), error::TrySendError<T>> {
self.inner.try_send(value)
}
/// Reserves capacity to send a value.
pub async fn reserve(&self) -> Result<Permit<'_, T>, error::SendError<()>> {
use crate::tracing::Instrument;
let span = crate::tracing::debug_span!("mpsc::reserve");
async {
// First acquire the operation through the coop system
self.send_op.acquire().await;
// Then perform the actual reserve
self.inner.reserve().await.map(|inner| Permit { inner })
}
.instrument(span)
.await
}
/// Tries to reserve capacity to send a value without waiting.
pub fn try_reserve(&self) -> Result<Permit<'_, T>, error::TrySendError<()>> {
self.inner.try_reserve().map(|inner| Permit { inner })
}
/// Reserves capacity to send n values.
pub async fn reserve_many(
&self,
n: usize,
) -> Result<PermitIterator<'_, T>, error::SendError<()>> {
use crate::tracing::Instrument;
let span = crate::tracing::debug_span!("mpsc::reserve_many");
async {
// First acquire the operation through the coop system
// For reserve_many we'll just acquire once, not n times
self.send_op.acquire().await;
// Then perform the actual reserve_many
self.inner
.reserve_many(n)
.await
.map(|inner| PermitIterator { inner })
}
.instrument(span)
.await
}
/// Returns `true` if the channel is closed.
pub fn is_closed(&self) -> bool {
self.inner.is_closed()
}
/// Returns the current capacity of the channel.
pub fn capacity(&self) -> usize {
self.inner.capacity()
}
/// Returns true if the send half of the channel is closed.
pub fn same_channel(&self, other: &Self) -> bool {
self.inner.same_channel(&other.inner)
}
/// Creates a new `WeakSender` for this channel.
pub fn downgrade(&self) -> WeakSender<T> {
WeakSender {
inner: self.inner.downgrade(),
send_op: self.send_op,
}
}
}
impl<T> Clone for Sender<T> {
fn clone(&self) -> Self {
Self {
inner: self.inner.clone(),
send_op: self.send_op,
}
}
}
impl<T> Receiver<T> {
/// Receives the next value for this receiver.
pub async fn recv(&mut self) -> Option<T> {
use crate::tracing::Instrument;
let span = crate::tracing::debug_span!("mpsc::recv");
async {
// First acquire the operation through the coop system
self.recv_op.acquire().await;
// Then perform the actual receive
self.inner.recv().await
}
.instrument(span)
.await
}
/// Attempts to receive a value from the channel without blocking.
pub fn try_recv(&mut self) -> Result<T, error::TryRecvError> {
self.inner.try_recv()
}
/// Closes the receiving half of a channel.
pub fn close(&mut self) {
self.inner.close()
}
}
impl<T> UnboundedSender<T> {
/// Sends a value through the channel.
pub fn send(&self, value: T) -> Result<(), error::SendError<T>> {
// The unbounded sender doesn't block right now
// TODO figure out how to integrate this with the coop system while
// still preserving a senders message ordering
self.inner.send(value)
}
/// Returns `true` if the channel is closed.
pub fn is_closed(&self) -> bool {
self.inner.is_closed()
}
/// Returns true if the send half of the channel is closed.
pub fn same_channel(&self, other: &Self) -> bool {
self.inner.same_channel(&other.inner)
}
/// Creates a new `WeakUnboundedSender` for this channel.
pub fn downgrade(&self) -> WeakUnboundedSender<T> {
WeakUnboundedSender {
inner: self.inner.downgrade(),
send_op: self.send_op,
}
}
}
impl<T> Clone for UnboundedSender<T> {
fn clone(&self) -> Self {
Self {
inner: self.inner.clone(),
send_op: self.send_op,
}
}
}
impl<T> UnboundedReceiver<T> {
/// Receives the next value for this receiver.
pub async fn recv(&mut self) -> Option<T> {
use crate::tracing::Instrument;
let span = crate::tracing::debug_span!("mpsc::unbounded_recv");
async {
// First acquire the operation through the coop system
self.recv_op.acquire().await;
// Then perform the actual receive
self.inner.recv().await
}
.instrument(span)
.await
}
/// Attempts to receive a value from the channel without blocking.
pub fn try_recv(&mut self) -> Result<T, error::TryRecvError> {
self.inner.try_recv()
}
/// Closes the receiving half of a channel.
pub fn close(&mut self) {
self.inner.close()
}
}
impl<'a, T> Permit<'a, T> {
/// Sends a value using the permit.
pub fn send(self, value: T) {
self.inner.send(value)
}
}
impl<T> OwnedPermit<T> {
/// Sends a value using the permit.
pub fn send(self, value: T) -> Sender<T> {
let inner = self.inner.send(value);
let send_op = self.send_op;
Sender { inner, send_op }
}
}
impl<'a, T> Iterator for PermitIterator<'a, T> {
type Item = Permit<'a, T>;
fn next(&mut self) -> Option<Self::Item> {
self.inner.next().map(|inner| Permit { inner })
}
}
impl<T> WeakSender<T> {
/// Attempts to upgrade the `WeakSender` to a `Sender`.
pub fn upgrade(&self) -> Option<Sender<T>> {
self.inner.upgrade().map(|inner| Sender {
inner,
send_op: self.send_op,
})
}
}
impl<T> Clone for WeakSender<T> {
fn clone(&self) -> Self {
Self {
inner: self.inner.clone(),
send_op: self.send_op,
}
}
}
impl<T> WeakUnboundedSender<T> {
/// Attempts to upgrade the `WeakUnboundedSender` to an `UnboundedSender`.
pub fn upgrade(&self) -> Option<UnboundedSender<T>> {
self.inner.upgrade().map(|inner| UnboundedSender {
inner,
send_op: self.send_op,
})
}
}
impl<T> Clone for WeakUnboundedSender<T> {
fn clone(&self) -> Self {
Self {
inner: self.inner.clone(),
send_op: self.send_op,
}
}
}
/// Creates a bounded mpsc channel for communicating between asynchronous tasks with backpressure.
pub fn channel<T>(buffer: usize) -> (Sender<T>, Receiver<T>) {
let (tx, rx) = mpsc::channel(buffer);
let tx = Sender {
inner: tx,
send_op: Operation::register(),
};
let rx = Receiver {
inner: rx,
recv_op: Operation::register(),
};
(tx, rx)
}
/// Creates an unbounded mpsc channel for communicating between asynchronous tasks without backpressure.
pub fn unbounded_channel<T>() -> (UnboundedSender<T>, UnboundedReceiver<T>) {
let (tx, rx) = mpsc::unbounded_channel();
let tx = UnboundedSender {
inner: tx,
send_op: Operation::register(),
};
let rx = UnboundedReceiver {
inner: rx,
recv_op: Operation::register(),
};
(tx, rx)
}
}
// When the coop feature is enabled, export our wrapped implementation
#[cfg(any(test, feature = "coop"))]
pub use coop_impl::*;
// Otherwise, re-export tokio's mpsc module directly
#[cfg(not(any(test, feature = "coop")))]
pub use tokio::sync::mpsc::*;