587 lines
15 KiB
Rust
587 lines
15 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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/*!
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Message passing
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*/
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use cast;
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use either::{Either, Left, Right};
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use kinds::Owned;
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use option::{Option, Some, None};
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use uint;
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use unstable;
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use vec;
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use unstable::Exclusive;
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use pipes::{recv, try_recv, wait_many, peek, PacketHeader};
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// FIXME #5160: Making this public exposes some plumbing from
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// pipes. Needs some refactoring
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pub use pipes::Selectable;
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/// A trait for things that can send multiple messages.
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pub trait GenericChan<T> {
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/// Sends a message.
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fn send(&self, x: T);
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}
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/// Things that can send multiple messages and can detect when the receiver
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/// is closed
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pub trait GenericSmartChan<T> {
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/// Sends a message, or report if the receiver has closed the connection.
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fn try_send(&self, x: T) -> bool;
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}
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/// A trait for things that can receive multiple messages.
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pub trait GenericPort<T> {
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/// Receives a message, or fails if the connection closes.
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fn recv(&self) -> T;
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/** Receives a message, or returns `none` if
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the connection is closed or closes.
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*/
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fn try_recv(&self) -> Option<T>;
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}
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/// Ports that can `peek`
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pub trait Peekable<T> {
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/// Returns true if a message is available
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fn peek(&self) -> bool;
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}
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// Streams - Make pipes a little easier in general.
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/*proto! streamp (
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Open:send<T: Owned> {
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data(T) -> Open<T>
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}
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)*/
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#[allow(non_camel_case_types)]
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pub mod streamp {
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priv use core::kinds::Owned;
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pub fn init<T: Owned>() -> (client::Open<T>, server::Open<T>) {
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pub use core::pipes::HasBuffer;
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::core::pipes::entangle()
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}
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#[allow(non_camel_case_types)]
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pub enum Open<T> { pub data(T, server::Open<T>), }
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#[allow(non_camel_case_types)]
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pub mod client {
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priv use core::kinds::Owned;
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#[allow(non_camel_case_types)]
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pub fn try_data<T: Owned>(pipe: Open<T>, x_0: T) ->
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::core::option::Option<Open<T>> {
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{
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use super::data;
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let (c, s) = ::core::pipes::entangle();
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let message = data(x_0, s);
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if ::core::pipes::send(pipe, message) {
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::core::pipes::rt::make_some(c)
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} else { ::core::pipes::rt::make_none() }
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}
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}
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#[allow(non_camel_case_types)]
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pub fn data<T: Owned>(pipe: Open<T>, x_0: T) -> Open<T> {
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{
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use super::data;
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let (c, s) = ::core::pipes::entangle();
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let message = data(x_0, s);
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::core::pipes::send(pipe, message);
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c
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}
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}
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#[allow(non_camel_case_types)]
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pub type Open<T> = ::core::pipes::SendPacket<super::Open<T>>;
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}
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#[allow(non_camel_case_types)]
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pub mod server {
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#[allow(non_camel_case_types)]
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pub type Open<T> = ::core::pipes::RecvPacket<super::Open<T>>;
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}
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}
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/// An endpoint that can send many messages.
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pub struct Chan<T> {
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mut endp: Option<streamp::client::Open<T>>
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}
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/// An endpoint that can receive many messages.
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pub struct Port<T> {
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mut endp: Option<streamp::server::Open<T>>,
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}
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/** Creates a `(Port, Chan)` pair.
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These allow sending or receiving an unlimited number of messages.
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*/
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pub fn stream<T:Owned>() -> (Port<T>, Chan<T>) {
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let (c, s) = streamp::init();
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(Port { endp: Some(s) }, Chan { endp: Some(c) })
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}
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impl<T: Owned> GenericChan<T> for Chan<T> {
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#[inline(always)]
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fn send(&self, x: T) {
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let mut endp = None;
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endp <-> self.endp;
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self.endp = Some(
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streamp::client::data(endp.unwrap(), x))
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}
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}
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impl<T: Owned> GenericSmartChan<T> for Chan<T> {
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#[inline(always)]
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fn try_send(&self, x: T) -> bool {
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let mut endp = None;
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endp <-> self.endp;
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match streamp::client::try_data(endp.unwrap(), x) {
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Some(next) => {
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self.endp = Some(next);
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true
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}
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None => false
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}
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}
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}
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impl<T: Owned> GenericPort<T> for Port<T> {
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#[inline(always)]
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fn recv(&self) -> T {
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let mut endp = None;
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endp <-> self.endp;
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let streamp::data(x, endp) = recv(endp.unwrap());
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self.endp = Some(endp);
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x
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}
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#[inline(always)]
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fn try_recv(&self) -> Option<T> {
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let mut endp = None;
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endp <-> self.endp;
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match try_recv(endp.unwrap()) {
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Some(streamp::data(x, endp)) => {
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self.endp = Some(endp);
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Some(x)
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}
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None => None
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}
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}
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}
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impl<T: Owned> Peekable<T> for Port<T> {
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#[inline(always)]
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fn peek(&self) -> bool {
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let mut endp = None;
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endp <-> self.endp;
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let peek = match &endp {
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&Some(ref endp) => peek(endp),
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&None => fail!(~"peeking empty stream")
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};
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self.endp <-> endp;
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peek
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}
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}
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impl<T: Owned> Selectable for Port<T> {
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fn header(&self) -> *PacketHeader {
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unsafe {
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match self.endp {
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Some(ref endp) => endp.header(),
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None => fail!(~"peeking empty stream")
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}
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}
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}
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}
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/// Treat many ports as one.
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pub struct PortSet<T> {
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mut ports: ~[Port<T>],
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}
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pub impl<T: Owned> PortSet<T> {
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fn new() -> PortSet<T> {
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PortSet {
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ports: ~[]
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}
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}
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fn add(&self, port: Port<T>) {
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self.ports.push(port)
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}
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fn chan(&self) -> Chan<T> {
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let (po, ch) = stream();
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self.add(po);
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ch
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}
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}
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impl<T:Owned> GenericPort<T> for PortSet<T> {
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fn try_recv(&self) -> Option<T> {
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let mut result = None;
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// we have to swap the ports array so we aren't borrowing
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// aliasable mutable memory.
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let mut ports = ~[];
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ports <-> self.ports;
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while result.is_none() && ports.len() > 0 {
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let i = wait_many(ports);
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match ports[i].try_recv() {
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Some(m) => {
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result = Some(m);
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}
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None => {
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// Remove this port.
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let _ = ports.swap_remove(i);
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}
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}
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}
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ports <-> self.ports;
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result
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}
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fn recv(&self) -> T {
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self.try_recv().expect("port_set: endpoints closed")
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}
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}
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impl<T: Owned> Peekable<T> for PortSet<T> {
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fn peek(&self) -> bool {
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// It'd be nice to use self.port.each, but that version isn't
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// pure.
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for uint::range(0, vec::uniq_len(&const self.ports)) |i| {
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// XXX: Botch pending demuting.
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unsafe {
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let port: &Port<T> = cast::transmute(&mut self.ports[i]);
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if port.peek() { return true }
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}
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}
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false
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}
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}
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/// A channel that can be shared between many senders.
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pub struct SharedChan<T> {
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ch: Exclusive<Chan<T>>
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}
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impl<T: Owned> SharedChan<T> {
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/// Converts a `chan` into a `shared_chan`.
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pub fn new(c: Chan<T>) -> SharedChan<T> {
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SharedChan { ch: unstable::exclusive(c) }
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}
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}
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impl<T: Owned> GenericChan<T> for SharedChan<T> {
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fn send(&self, x: T) {
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let mut xx = Some(x);
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do self.ch.with_imm |chan| {
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let mut x = None;
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x <-> xx;
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chan.send(x.unwrap())
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}
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}
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}
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impl<T: Owned> GenericSmartChan<T> for SharedChan<T> {
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fn try_send(&self, x: T) -> bool {
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let mut xx = Some(x);
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do self.ch.with_imm |chan| {
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let mut x = None;
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x <-> xx;
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chan.try_send(x.unwrap())
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}
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}
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}
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impl<T: Owned> ::clone::Clone for SharedChan<T> {
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fn clone(&self) -> SharedChan<T> {
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SharedChan { ch: self.ch.clone() }
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}
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}
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/*proto! oneshot (
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Oneshot:send<T:Owned> {
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send(T) -> !
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}
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)*/
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#[allow(non_camel_case_types)]
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pub mod oneshot {
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priv use core::kinds::Owned;
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use ptr::to_unsafe_ptr;
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pub fn init<T: Owned>() -> (client::Oneshot<T>, server::Oneshot<T>) {
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pub use core::pipes::HasBuffer;
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let buffer =
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~::core::pipes::Buffer{
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header: ::core::pipes::BufferHeader(),
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data: __Buffer{
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Oneshot: ::core::pipes::mk_packet::<Oneshot<T>>()
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},
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};
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do ::core::pipes::entangle_buffer(buffer) |buffer, data| {
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{
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data.Oneshot.set_buffer(buffer);
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to_unsafe_ptr(&data.Oneshot)
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}
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}
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}
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#[allow(non_camel_case_types)]
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pub enum Oneshot<T> { pub send(T), }
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#[allow(non_camel_case_types)]
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pub struct __Buffer<T> {
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Oneshot: ::core::pipes::Packet<Oneshot<T>>,
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}
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#[allow(non_camel_case_types)]
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pub mod client {
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priv use core::kinds::Owned;
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#[allow(non_camel_case_types)]
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pub fn try_send<T: Owned>(pipe: Oneshot<T>, x_0: T) ->
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::core::option::Option<()> {
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{
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use super::send;
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let message = send(x_0);
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if ::core::pipes::send(pipe, message) {
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::core::pipes::rt::make_some(())
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} else { ::core::pipes::rt::make_none() }
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}
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}
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#[allow(non_camel_case_types)]
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pub fn send<T: Owned>(pipe: Oneshot<T>, x_0: T) {
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{
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use super::send;
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let message = send(x_0);
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::core::pipes::send(pipe, message);
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}
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}
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#[allow(non_camel_case_types)]
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pub type Oneshot<T> =
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::core::pipes::SendPacketBuffered<super::Oneshot<T>,
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super::__Buffer<T>>;
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}
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#[allow(non_camel_case_types)]
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pub mod server {
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#[allow(non_camel_case_types)]
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pub type Oneshot<T> =
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::core::pipes::RecvPacketBuffered<super::Oneshot<T>,
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super::__Buffer<T>>;
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}
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}
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/// The send end of a oneshot pipe.
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pub struct ChanOne<T> {
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contents: oneshot::client::Oneshot<T>
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}
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impl<T> ChanOne<T> {
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pub fn new(contents: oneshot::client::Oneshot<T>) -> ChanOne<T> {
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ChanOne {
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contents: contents
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}
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}
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}
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/// The receive end of a oneshot pipe.
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pub struct PortOne<T> {
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contents: oneshot::server::Oneshot<T>
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}
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impl<T> PortOne<T> {
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pub fn new(contents: oneshot::server::Oneshot<T>) -> PortOne<T> {
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PortOne {
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contents: contents
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}
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}
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}
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/// Initialiase a (send-endpoint, recv-endpoint) oneshot pipe pair.
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pub fn oneshot<T: Owned>() -> (PortOne<T>, ChanOne<T>) {
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let (chan, port) = oneshot::init();
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(PortOne::new(port), ChanOne::new(chan))
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}
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pub impl<T: Owned> PortOne<T> {
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fn recv(self) -> T { recv_one(self) }
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fn try_recv(self) -> Option<T> { try_recv_one(self) }
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fn unwrap(self) -> oneshot::server::Oneshot<T> {
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match self {
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PortOne { contents: s } => s
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}
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}
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}
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pub impl<T: Owned> ChanOne<T> {
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fn send(self, data: T) { send_one(self, data) }
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fn try_send(self, data: T) -> bool { try_send_one(self, data) }
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fn unwrap(self) -> oneshot::client::Oneshot<T> {
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match self {
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ChanOne { contents: s } => s
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}
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}
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}
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/**
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* Receive a message from a oneshot pipe, failing if the connection was
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* closed.
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*/
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pub fn recv_one<T: Owned>(port: PortOne<T>) -> T {
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match port {
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PortOne { contents: port } => {
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let oneshot::send(message) = recv(port);
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message
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}
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}
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}
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/// Receive a message from a oneshot pipe unless the connection was closed.
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pub fn try_recv_one<T: Owned> (port: PortOne<T>) -> Option<T> {
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match port {
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PortOne { contents: port } => {
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let message = try_recv(port);
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if message.is_none() {
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None
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} else {
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let oneshot::send(message) = message.unwrap();
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Some(message)
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}
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}
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}
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}
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/// Send a message on a oneshot pipe, failing if the connection was closed.
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pub fn send_one<T: Owned>(chan: ChanOne<T>, data: T) {
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match chan {
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ChanOne { contents: chan } => oneshot::client::send(chan, data),
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}
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}
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/**
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* Send a message on a oneshot pipe, or return false if the connection was
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* closed.
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*/
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pub fn try_send_one<T: Owned>(chan: ChanOne<T>, data: T) -> bool {
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match chan {
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ChanOne { contents: chan } => {
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oneshot::client::try_send(chan, data).is_some()
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}
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}
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}
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/// Returns the index of an endpoint that is ready to receive.
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pub fn selecti<T: Selectable>(endpoints: &[T]) -> uint {
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wait_many(endpoints)
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}
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/// Returns 0 or 1 depending on which endpoint is ready to receive
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pub fn select2i<A: Selectable, B: Selectable>(a: &A, b: &B) ->
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Either<(), ()> {
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match wait_many([a.header(), b.header()]) {
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0 => Left(()),
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1 => Right(()),
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_ => fail!(~"wait returned unexpected index")
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}
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}
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/// Receive a message from one of two endpoints.
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pub trait Select2<T: Owned, U: Owned> {
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/// Receive a message or return `None` if a connection closes.
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fn try_select(&self) -> Either<Option<T>, Option<U>>;
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/// Receive a message or fail if a connection closes.
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fn select(&self) -> Either<T, U>;
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}
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impl<T: Owned, U: Owned,
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Left: Selectable + GenericPort<T>,
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Right: Selectable + GenericPort<U>>
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Select2<T, U> for (Left, Right) {
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fn select(&self) -> Either<T, U> {
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match *self {
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(ref lp, ref rp) => match select2i(lp, rp) {
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Left(()) => Left (lp.recv()),
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Right(()) => Right(rp.recv())
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}
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}
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}
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fn try_select(&self) -> Either<Option<T>, Option<U>> {
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match *self {
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(ref lp, ref rp) => match select2i(lp, rp) {
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Left(()) => Left (lp.try_recv()),
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Right(()) => Right(rp.try_recv())
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}
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}
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}
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}
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#[cfg(test)]
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mod test {
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use either::Right;
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|
use super::{Chan, Port, oneshot, recv_one, stream};
|
|
|
|
#[test]
|
|
fn test_select2() {
|
|
let (p1, c1) = stream();
|
|
let (p2, c2) = stream();
|
|
|
|
c1.send(~"abc");
|
|
|
|
match (p1, p2).select() {
|
|
Right(_) => fail!(),
|
|
_ => ()
|
|
}
|
|
|
|
c2.send(123);
|
|
}
|
|
|
|
#[test]
|
|
fn test_oneshot() {
|
|
let (p, c) = oneshot();
|
|
|
|
c.send(());
|
|
|
|
p.recv()
|
|
}
|
|
|
|
#[test]
|
|
fn test_peek_terminated() {
|
|
let (port, chan): (Port<int>, Chan<int>) = stream();
|
|
|
|
{
|
|
// Destroy the channel
|
|
let _chan = chan;
|
|
}
|
|
|
|
assert!(!port.peek());
|
|
}
|
|
}
|