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// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
/*!
Higher level communication abstractions.
*/
#[allow(missing_doc)];
use std::comm::{GenericChan, GenericSmartChan, GenericPort};
use std::comm::{Chan, Port, Peekable};
use std::comm;
/// An extension of `pipes::stream` that allows both sending and receiving.
pub struct DuplexStream<T, U> {
priv chan: Chan<T>,
priv port: Port<U>,
}
// Allow these methods to be used without import:
impl<T:Send,U:Send> DuplexStream<T, U> {
pub fn send(&self, x: T) {
self.chan.send(x)
}
pub fn try_send(&self, x: T) -> bool {
self.chan.try_send(x)
}
pub fn recv(&self, ) -> U {
self.port.recv()
}
pub fn try_recv(&self) -> Option<U> {
self.port.try_recv()
}
pub fn peek(&self) -> bool {
self.port.peek()
}
}
impl<T:Send,U:Send> GenericChan<T> for DuplexStream<T, U> {
fn send(&self, x: T) {
self.chan.send(x)
}
}
impl<T:Send,U:Send> GenericSmartChan<T> for DuplexStream<T, U> {
fn try_send(&self, x: T) -> bool {
self.chan.try_send(x)
}
}
impl<T:Send,U:Send> GenericPort<U> for DuplexStream<T, U> {
fn recv(&self) -> U {
self.port.recv()
}
fn try_recv(&self) -> Option<U> {
self.port.try_recv()
}
}
impl<T:Send,U:Send> Peekable<U> for DuplexStream<T, U> {
fn peek(&self) -> bool {
self.port.peek()
}
}
/// Creates a bidirectional stream.
pub fn DuplexStream<T:Send,U:Send>()
-> (DuplexStream<T, U>, DuplexStream<U, T>)
{
let (p1, c2) = comm::stream();
let (p2, c1) = comm::stream();
(DuplexStream {
chan: c1,
port: p1
},
DuplexStream {
chan: c2,
port: p2
})
}
/// An extension of `pipes::stream` that provides synchronous message sending.
pub struct SyncChan<T> { priv duplex_stream: DuplexStream<T, ()> }
/// An extension of `pipes::stream` that acknowledges each message received.
pub struct SyncPort<T> { priv duplex_stream: DuplexStream<(), T> }
impl<T: Send> GenericChan<T> for SyncChan<T> {
fn send(&self, val: T) {
assert!(self.try_send(val), "SyncChan.send: receiving port closed");
}
}
impl<T: Send> GenericSmartChan<T> for SyncChan<T> {
/// Sends a message, or report if the receiver has closed the connection before receiving.
fn try_send(&self, val: T) -> bool {
self.duplex_stream.try_send(val) && self.duplex_stream.try_recv().is_some()
}
}
impl<T: Send> GenericPort<T> for SyncPort<T> {
fn recv(&self) -> T {
self.try_recv().expect("SyncPort.recv: sending channel closed")
}
fn try_recv(&self) -> Option<T> {
do self.duplex_stream.try_recv().map_move |val| {
self.duplex_stream.try_send(());
val
}
}
}
impl<T: Send> Peekable<T> for SyncPort<T> {
fn peek(&self) -> bool {
self.duplex_stream.peek()
}
}
/// Creates a stream whose channel, upon sending a message, blocks until the message is received.
pub fn rendezvous<T: Send>() -> (SyncPort<T>, SyncChan<T>) {
let (chan_stream, port_stream) = DuplexStream();
(SyncPort { duplex_stream: port_stream }, SyncChan { duplex_stream: chan_stream })
}
#[cfg(test)]
mod test {
use comm::{DuplexStream, rendezvous};
use std::rt::test::run_in_newsched_task;
use std::task::spawn_unlinked;
#[test]
pub fn DuplexStream1() {
let (left, right) = DuplexStream();
left.send(~"abc");
right.send(123);
assert!(left.recv() == 123);
assert!(right.recv() == ~"abc");
}
#[test]
pub fn basic_rendezvous_test() {
let (port, chan) = rendezvous();
do spawn {
chan.send("abc");
}
assert!(port.recv() == "abc");
}
#[test]
fn recv_a_lot() {
// Rendezvous streams should be able to handle any number of messages being sent
do run_in_newsched_task {
let (port, chan) = rendezvous();
do spawn {
do 1000000.times { chan.send(()) }
}
do 1000000.times { port.recv() }
}
}
#[test]
fn send_and_fail_and_try_recv() {
let (port, chan) = rendezvous();
do spawn_unlinked {
chan.duplex_stream.send(()); // Can't access this field outside this module
fail!()
}
port.recv()
}
#[test]
fn try_send_and_recv_then_fail_before_ack() {
let (port, chan) = rendezvous();
do spawn_unlinked {
port.duplex_stream.recv();
fail!()
}
chan.try_send(());
}
#[test]
#[should_fail]
fn send_and_recv_then_fail_before_ack() {
let (port, chan) = rendezvous();
do spawn_unlinked {
port.duplex_stream.recv();
fail!()
}
chan.send(());
}
}
|
