Simplify oneshot and mpsc implementations

actix-connect/Cargo.toml

@@ -36,7 +36,7 @@ uri = ["http"]
 actix-service = "1.0.0"
 actix-codec = "0.2.0"
 actix-utils = "1.0.0-alpha.3"
-actix-rt = "1.0.0-alpha.3"
+actix-rt = "1.0.0"
 derive_more = "0.99.2"
 either = "1.5.2"
 futures = "0.3.1"

actix-ioframe/Cargo.toml

@@ -21,7 +21,7 @@ path = "src/lib.rs"
 actix-service = "1.0.0"
 actix-codec = "0.2.0"
 actix-utils = "1.0.0-alpha.2"
-actix-rt = "1.0.0-alpha.2"
+actix-rt = "1.0.0"
 bytes = "0.5"
 either = "1.5.2"
 futures = "0.3.1"

actix-macros/Cargo.toml

@@ -18,4 +18,4 @@ quote = "^1"
 syn = { version = "^1", features = ["full"] }
 
 [dev-dependencies]
-actix-rt = { version = "1.0.0-alpha.3" }
+actix-rt = { version = "1.0.0" }

actix-server/Cargo.toml

@@ -22,7 +22,7 @@ default = []
 
 [dependencies]
 actix-service = "1.0.0"
-actix-rt = "1.0.0-alpha.3"
+actix-rt = "1.0.0"
 actix-codec = "0.2.0"
 actix-utils = "1.0.0-alpha.3"
 

actix-service/Cargo.toml

@@ -26,4 +26,4 @@ futures-util = "0.3.1"
 pin-project = "0.4.6"
 
 [dev-dependencies]
-actix-rt = "1.0.0-alpha.3"
+actix-rt = "1.0.0"

actix-testing/Cargo.toml

@@ -17,7 +17,7 @@ name = "actix_testing"
 path = "src/lib.rs"
 
 [dependencies]
-actix-rt = "1.0.0-alpha.3"
+actix-rt = "1.0.0"
 actix-macros = "0.1.0"
 actix-server = "1.0.0-alpha.3"
 actix-service = "1.0.0"

actix-tls/Cargo.toml

@@ -35,7 +35,7 @@ nativetls = ["native-tls", "tokio-tls"]
 actix-service = "1.0.0"
 actix-codec = "0.2.0"
 actix-utils = "1.0.0-alpha.3"
-actix-rt = "1.0.0-alpha.3"
+actix-rt = "1.0.0"
 derive_more = "0.99.2"
 either = "1.5.2"
 futures = "0.3.1"

actix-utils/CHANGES.md

@@ -1,5 +1,9 @@
 # Changes
 
+## [1.0.0] - 2019-12-11
+
+* Simplify oneshot and mpsc implementations
+
 ## [1.0.0-alpha.3] - 2019-12-07
 
 * Migrate to tokio 0.2

actix-utils/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "actix-utils"
-version = "1.0.0-alpha.3"
+version = "1.0.0"
 authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
 description = "Actix utils - various actix net related services"
 keywords = ["network", "framework", "async", "futures"]
@@ -9,7 +9,6 @@ repository = "https://github.com/actix/actix-net.git"
 documentation = "https://docs.rs/actix-utils/"
 categories = ["network-programming", "asynchronous"]
 license = "MIT/Apache-2.0"
-exclude = [".gitignore", ".travis.yml", ".cargo/config", "appveyor.yml"]
 edition = "2018"
 workspace = ".."
 
@@ -19,7 +18,7 @@ path = "src/lib.rs"
 
 [dependencies]
 actix-service = "1.0.0"
-actix-rt = "1.0.0-alpha.3"
+actix-rt = "1.0.0"
 actix-codec = "0.2.0"
 bytes = "0.5.2"
 either = "1.5.2"

actix-utils/src/cell.rs

@@ -2,16 +2,12 @@
 
 use std::cell::UnsafeCell;
 use std::fmt;
-use std::rc::{Rc, Weak};
+use std::rc::Rc;
 
 pub(crate) struct Cell<T> {
     pub(crate) inner: Rc<UnsafeCell<T>>,
 }
 
-pub(crate) struct WeakCell<T> {
-    inner: Weak<UnsafeCell<T>>,
-}
-
 impl<T> Clone for Cell<T> {
     fn clone(&self) -> Self {
         Self {
@@ -27,39 +23,25 @@ impl<T: fmt::Debug> fmt::Debug for Cell<T> {
 }
 
 impl<T> Cell<T> {
-    pub fn new(inner: T) -> Self {
+    pub(crate) fn new(inner: T) -> Self {
         Self {
             inner: Rc::new(UnsafeCell::new(inner)),
         }
     }
 
-    pub fn downgrade(&self) -> WeakCell<T> {
-        WeakCell {
-            inner: Rc::downgrade(&self.inner),
-        }
+    pub(crate) fn strong_count(&self) -> usize {
+        Rc::strong_count(&self.inner)
     }
 
-    pub fn get_ref(&self) -> &T {
+    pub(crate) fn get_ref(&self) -> &T {
         unsafe { &*self.inner.as_ref().get() }
     }
 
-    pub fn get_mut(&mut self) -> &mut T {
+    pub(crate) fn get_mut(&mut self) -> &mut T {
         unsafe { &mut *self.inner.as_ref().get() }
     }
-}
 
-impl<T> WeakCell<T> {
-    pub fn upgrade(&self) -> Option<Cell<T>> {
-        if let Some(inner) = self.inner.upgrade() {
-            Some(Cell { inner })
-        } else {
-            None
-        }
-    }
-}
-
-impl<T: fmt::Debug> fmt::Debug for WeakCell<T> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        self.inner.fmt(f)
+    pub(crate) unsafe fn get_mut_unsafe(&self) -> &mut T {
+        &mut *self.inner.as_ref().get()
     }
 }

actix-utils/src/mpsc.rs

@@ -1,34 +1,27 @@
-//! A multi-producer, single-consumer, futures-aware, FIFO queue with back
-//! pressure, for use communicating between tasks on the same thread.
-//!
-//! These queues are the same as those in `futures::sync`, except they're not
-//! intended to be sent across threads.
-
+//! A multi-producer, single-consumer, futures-aware, FIFO queue.
 use std::any::Any;
-use std::cell::RefCell;
 use std::collections::VecDeque;
 use std::error::Error;
+use std::fmt;
 use std::pin::Pin;
-use std::rc::{Rc, Weak};
 use std::task::{Context, Poll};
-use std::{fmt, mem};
 
 use futures::{Sink, Stream};
 
+use crate::cell::Cell;
 use crate::task::LocalWaker;
 
 /// Creates a unbounded in-memory channel with buffered storage.
 pub fn channel<T>() -> (Sender<T>, Receiver<T>) {
-    let shared = Rc::new(RefCell::new(Shared {
+    let shared = Cell::new(Shared {
+        has_receiver: true,
         buffer: VecDeque::new(),
         blocked_recv: LocalWaker::new(),
-    }));
+    });
     let sender = Sender {
-        shared: Rc::downgrade(&shared),
-    };
-    let receiver = Receiver {
-        state: State::Open(shared),
+        shared: shared.clone(),
     };
+    let receiver = Receiver { shared };
     (sender, receiver)
 }
 
@@ -36,6 +29,7 @@ pub fn channel<T>() -> (Sender<T>, Receiver<T>) {
 struct Shared<T> {
     buffer: VecDeque<T>,
     blocked_recv: LocalWaker,
+    has_receiver: bool,
 }
 
 /// The transmission end of a channel.
@@ -43,18 +37,18 @@ struct Shared<T> {
 /// This is created by the `channel` function.
 #[derive(Debug)]
 pub struct Sender<T> {
-    shared: Weak<RefCell<Shared<T>>>,
+    shared: Cell<Shared<T>>,
 }
 
+impl<T> Unpin for Sender<T> {}
+
 impl<T> Sender<T> {
     /// Sends the provided message along this channel.
     pub fn send(&self, item: T) -> Result<(), SendError<T>> {
-        let shared = match self.shared.upgrade() {
-            Some(shared) => shared,
-            None => return Err(SendError(item)), // receiver was dropped
+        let shared = unsafe { self.shared.get_mut_unsafe() };
+        if !shared.has_receiver {
+            return Err(SendError(item)); // receiver was dropped
         };
-        let mut shared = shared.borrow_mut();
-
         shared.buffer.push_back(item);
         shared.blocked_recv.wake();
         Ok(())
@@ -91,17 +85,13 @@ impl<T> Sink<T> for Sender<T> {
 
 impl<T> Drop for Sender<T> {
     fn drop(&mut self) {
-        let shared = match self.shared.upgrade() {
-            Some(shared) => shared,
-            None => return,
-        };
-        // The number of existing `Weak` indicates if we are possibly the last
-        // `Sender`. If we are the last, we possibly must notify a blocked
-        // `Receiver`. `self.shared` is always one of the `Weak` to this shared
-        // data. Therefore the smallest possible Rc::weak_count(&shared) is 1.
-        if Rc::weak_count(&shared) == 1 {
+        let count = self.shared.strong_count();
+        let shared = self.shared.get_mut();
+
+        // check is last sender is about to drop
+        if shared.has_receiver && count == 2 {
             // Wake up receiver as its stream has ended
-            shared.borrow_mut().blocked_recv.wake();
+            shared.blocked_recv.wake();
         }
     }
 }
@@ -111,56 +101,23 @@ impl<T> Drop for Sender<T> {
 /// This is created by the `channel` function.
 #[derive(Debug)]
 pub struct Receiver<T> {
-    state: State<T>,
+    shared: Cell<Shared<T>>,
 }
 
 impl<T> Unpin for Receiver<T> {}
 
-/// Possible states of a receiver. We're either Open (can receive more messages)
-/// or we're closed with a list of messages we have left to receive.
-#[derive(Debug)]
-enum State<T> {
-    Open(Rc<RefCell<Shared<T>>>),
-    Closed(VecDeque<T>),
-}
-
-impl<T> Receiver<T> {
-    /// Closes the receiving half
-    ///
-    /// This prevents any further messages from being sent on the channel while
-    /// still enabling the receiver to drain messages that are buffered.
-    pub fn close(&mut self) {
-        let items = match self.state {
-            State::Open(ref state) => {
-                let mut state = state.borrow_mut();
-                mem::replace(&mut state.buffer, VecDeque::new())
-            }
-            State::Closed(_) => return,
-        };
-        self.state = State::Closed(items);
-    }
-}
-
 impl<T> Stream for Receiver<T> {
     type Item = T;
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        let me = match self.state {
-            State::Open(ref mut me) => me,
-            State::Closed(ref mut items) => return Poll::Ready(items.pop_front()),
-        };
-
-        if let Some(shared) = Rc::get_mut(me) {
+        if self.shared.strong_count() == 1 {
             // All senders have been dropped, so drain the buffer and end the
             // stream.
-            return Poll::Ready(shared.borrow_mut().buffer.pop_front());
-        }
-
-        let mut shared = me.borrow_mut();
-        if let Some(msg) = shared.buffer.pop_front() {
+            Poll::Ready(self.shared.get_mut().buffer.pop_front())
+        } else if let Some(msg) = self.shared.get_mut().buffer.pop_front() {
             Poll::Ready(Some(msg))
         } else {
-            shared.blocked_recv.register(cx.waker());
+            self.shared.get_mut().blocked_recv.register(cx.waker());
             Poll::Pending
         }
     }
@@ -168,7 +125,9 @@ impl<T> Stream for Receiver<T> {
 
 impl<T> Drop for Receiver<T> {
     fn drop(&mut self) {
-        self.close();
+        let shared = self.shared.get_mut();
+        shared.buffer.clear();
+        shared.has_receiver = false;
     }
 }
 
@@ -200,3 +159,38 @@ impl<T> SendError<T> {
         self.0
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use futures::future::lazy;
+    use futures::{Stream, StreamExt};
+
+    #[actix_rt::test]
+    async fn test_mpsc() {
+        let (tx, mut rx) = channel();
+        tx.send("test").unwrap();
+        assert_eq!(rx.next().await.unwrap(), "test");
+
+        let tx2 = tx.clone();
+        tx2.send("test2").unwrap();
+        assert_eq!(rx.next().await.unwrap(), "test2");
+
+        assert_eq!(
+            lazy(|cx| Pin::new(&mut rx).poll_next(cx)).await,
+            Poll::Pending
+        );
+        drop(tx2);
+        assert_eq!(
+            lazy(|cx| Pin::new(&mut rx).poll_next(cx)).await,
+            Poll::Pending
+        );
+        drop(tx);
+        assert_eq!(rx.next().await, None);
+
+        let (tx, rx) = channel();
+        tx.send("test").unwrap();
+        drop(rx);
+        assert!(tx.send("test").is_err());
+    }
+}

actix-utils/src/oneshot.rs

@@ -1,69 +1,45 @@
-//! A one-shot, futures-aware channel
-//!
-//! This channel is similar to that in `sync::oneshot` but cannot be sent across
-//! threads.
-
+//! A one-shot, futures-aware channel.
 use std::future::Future;
 use std::pin::Pin;
-use std::rc::Rc;
 use std::task::{Context, Poll};
 
 pub use futures::channel::oneshot::Canceled;
 
-use crate::cell::{Cell, WeakCell};
+use crate::cell::Cell;
 use crate::task::LocalWaker;
 
 /// Creates a new futures-aware, one-shot channel.
-///
-/// This function is the same as `sync::oneshot::channel` except that the
-/// returned values cannot be sent across threads.
 pub fn channel<T>() -> (Sender<T>, Receiver<T>) {
     let inner = Cell::new(Inner {
         value: None,
         rx_task: LocalWaker::new(),
     });
     let tx = Sender {
-        inner: inner.downgrade(),
-    };
-    let rx = Receiver {
-        state: State::Open(inner),
+        inner: inner.clone(),
     };
+    let rx = Receiver { inner };
     (tx, rx)
 }
 
 /// Represents the completion half of a oneshot through which the result of a
 /// computation is signaled.
-///
-/// This is created by the `unsync::oneshot::channel` function and is equivalent
-/// in functionality to `sync::oneshot::Sender` except that it cannot be sent
-/// across threads.
 #[derive(Debug)]
 pub struct Sender<T> {
-    inner: WeakCell<Inner<T>>,
+    inner: Cell<Inner<T>>,
 }
 
 /// A future representing the completion of a computation happening elsewhere in
 /// memory.
-///
-/// This is created by the `unsync::oneshot::channel` function and is equivalent
-/// in functionality to `sync::oneshot::Receiver` except that it cannot be sent
-/// across threads.
 #[derive(Debug)]
 #[must_use = "futures do nothing unless polled"]
 pub struct Receiver<T> {
-    state: State<T>,
+    inner: Cell<Inner<T>>,
 }
 
 // The channels do not ever project Pin to the inner T
 impl<T> Unpin for Receiver<T> {}
 impl<T> Unpin for Sender<T> {}
 
-#[derive(Debug)]
-enum State<T> {
-    Open(Cell<Inner<T>>),
-    Closed(Option<T>),
-}
-
 #[derive(Debug)]
 struct Inner<T> {
     value: Option<T>,
@@ -78,12 +54,12 @@ impl<T> Sender<T> {
     /// represents.
     ///
     /// If the value is successfully enqueued for the remote end to receive,
-    /// then `Ok(())` is returned. If the receiving end was deallocated before
+    /// then `Ok(())` is returned. If the receiving end was dropped before
     /// this function was called, however, then `Err` is returned with the value
     /// provided.
-    pub fn send(self, val: T) -> Result<(), T> {
-        if let Some(mut inner) = self.inner.upgrade() {
-            let inner = inner.get_mut();
+    pub fn send(mut self, val: T) -> Result<(), T> {
+        if self.inner.strong_count() == 2 {
+            let inner = self.inner.get_mut();
             inner.value = Some(val);
             inner.rx_task.wake();
             Ok(())
@@ -91,47 +67,12 @@ impl<T> Sender<T> {
             Err(val)
         }
     }
-
-    /// Tests to see whether this `Sender`'s corresponding `Receiver`
-    /// has gone away.
-    ///
-    /// This function can be used to learn about when the `Receiver` (consumer)
-    /// half has gone away and nothing will be able to receive a message sent
-    /// from `send`.
-    ///
-    /// Note that this function is intended to *not* be used in the context of a
-    /// future. If you're implementing a future you probably want to call the
-    /// `poll_cancel` function which will block the current task if the
-    /// cancellation hasn't happened yet. This can be useful when working on a
-    /// non-futures related thread, though, which would otherwise panic if
-    /// `poll_cancel` were called.
-    pub fn is_canceled(&self) -> bool {
-        self.inner.upgrade().is_none()
-    }
 }
 
 impl<T> Drop for Sender<T> {
     fn drop(&mut self) {
-        if let Some(inner) = self.inner.upgrade() {
-            inner.get_ref().rx_task.wake();
-        };
-    }
-}
-
-impl<T> Receiver<T> {
-    /// Gracefully close this receiver, preventing sending any future messages.
-    ///
-    /// Any `send` operation which happens after this method returns is
-    /// guaranteed to fail. Once this method is called the normal `poll` method
-    /// can be used to determine whether a message was actually sent or not. If
-    /// `Canceled` is returned from `poll` then no message was sent.
-    pub fn close(&mut self) {
-        match self.state {
-            State::Open(ref mut inner) => {
-                let value = inner.get_mut().value.take();
-                self.state = State::Closed(value);
-            }
-            State::Closed(_) => {}
+        if self.inner.strong_count() == 2 {
+            self.inner.get_ref().rx_task.wake();
         };
     }
 }
@@ -142,33 +83,48 @@ impl<T> Future for Receiver<T> {
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         let this = self.get_mut();
 
-        let inner = match this.state {
-            State::Open(ref mut inner) => inner,
-            State::Closed(ref mut item) => match item.take() {
-                Some(item) => return Poll::Ready(Ok(item)),
-                None => return Poll::Ready(Err(Canceled)),
-            },
-        };
-
         // If we've got a value, then skip the logic below as we're done.
-        if let Some(val) = inner.get_mut().value.take() {
+        if let Some(val) = this.inner.get_mut().value.take() {
             return Poll::Ready(Ok(val));
         }
 
-        // If we can get mutable access, then the sender has gone away. We
-        // didn't see a value above, so we're canceled. Otherwise we park
-        // our task and wait for a value to come in.
-        if Rc::get_mut(&mut inner.inner).is_some() {
+        // Check if sender is dropped and return error if it is.
+        if this.inner.strong_count() == 1 {
             Poll::Ready(Err(Canceled))
         } else {
-            inner.get_ref().rx_task.register(cx.waker());
+            this.inner.get_ref().rx_task.register(cx.waker());
             Poll::Pending
         }
     }
 }
 
-impl<T> Drop for Receiver<T> {
-    fn drop(&mut self) {
-        self.close();
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use futures::future::lazy;
+
+    #[actix_rt::test]
+    async fn test_oneshot() {
+        let (tx, rx) = channel();
+        tx.send("test").unwrap();
+        assert_eq!(rx.await.unwrap(), "test");
+
+        let (tx, rx) = channel();
+        drop(rx);
+        assert!(tx.send("test").is_err());
+
+        let (tx, rx) = channel::<&'static str>();
+        drop(tx);
+        assert!(rx.await.is_err());
+
+        let (tx, mut rx) = channel::<&'static str>();
+        assert_eq!(lazy(|cx| Pin::new(&mut rx).poll(cx)).await, Poll::Pending);
+        tx.send("test").unwrap();
+        assert_eq!(rx.await.unwrap(), "test");
+
+        let (tx, mut rx) = channel::<&'static str>();
+        assert_eq!(lazy(|cx| Pin::new(&mut rx).poll(cx)).await, Poll::Pending);
+        drop(tx);
+        assert!(rx.await.is_err());
     }
 }