rust/src/libstd/io/signal.rs
2013-11-11 20:44:07 -08:00

225 lines
7.2 KiB
Rust

// Copyright 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.
/*!
Signal handling
This modules provides bindings to receive signals safely, built on top of the
local I/O factory. There are a number of defined signals which can be caught,
but not all signals will work across all platforms (windows doesn't have
definitions for a number of signals.
*/
use clone::Clone;
use comm::{Port, SharedChan, stream};
use container::{Map, MutableMap};
use hashmap;
use io::io_error;
use option::{Some, None};
use result::{Err, Ok};
use rt::rtio::{IoFactory, RtioSignal, with_local_io};
#[repr(int)]
#[deriving(Eq, IterBytes)]
pub enum Signum {
/// Equivalent to SIGBREAK, delivered when the user presses Ctrl-Break.
Break = 21i,
/// Equivalent to SIGHUP, delivered when the user closes the terminal
/// window. On delivery of HangUp, the program is given approximately
/// 10 seconds to perfom any cleanup. After that, Windows will
/// unconditionally terminate it.
HangUp = 1i,
/// Equivalent to SIGINT, delivered when the user presses Ctrl-c.
Interrupt = 2i,
/// Equivalent to SIGQUIT, delivered when the user presses Ctrl-\.
Quit = 3i,
/// Equivalent to SIGTSTP, delivered when the user presses Ctrl-z.
StopTemporarily = 20i,
/// Equivalent to SIGUSR1.
User1 = 10i,
/// Equivalent to SIGUSR2.
User2 = 12i,
/// Equivalent to SIGWINCH, delivered when the console has been resized.
/// WindowSizeChange may not be delivered in a timely manner; size change
/// will only be detected when the cursor is being moved.
WindowSizeChange = 28i,
}
/// Listener provides a port to listen for registered signals.
///
/// Listener automatically unregisters its handles once it is out of scope.
/// However, clients can still unregister signums manually.
///
/// # Example
///
/// ```rust
/// use std::io::signal::{Listener, Interrupt};
///
/// let mut listener = Listener::new();
/// listener.register(signal::Interrupt);
///
/// do spawn {
/// loop {
/// match listener.port.recv() {
/// Interrupt => println("Got Interrupt'ed"),
/// _ => (),
/// }
/// }
/// }
///
/// ```
pub struct Listener {
/// A map from signums to handles to keep the handles in memory
priv handles: hashmap::HashMap<Signum, ~RtioSignal>,
/// chan is where all the handles send signums, which are received by
/// the clients from port.
priv chan: SharedChan<Signum>,
/// Clients of Listener can `recv()` from this port. This is exposed to
/// allow selection over this port as well as manipulation of the port
/// directly.
port: Port<Signum>,
}
impl Listener {
/// Creates a new listener for signals. Once created, signals are bound via
/// the `register` method (otherwise nothing will ever be received)
pub fn new() -> Listener {
let (port, chan) = stream();
Listener {
chan: SharedChan::new(chan),
port: port,
handles: hashmap::HashMap::new(),
}
}
/// Listen for a signal, returning true when successfully registered for
/// signum. Signals can be received using `recv()`.
///
/// Once a signal is registered, this listener will continue to receive
/// notifications of signals until it is unregistered. This occurs
/// regardless of the number of other listeners registered in other tasks
/// (or on this task).
///
/// Signals are still received if there is no task actively waiting for
/// a signal, and a later call to `recv` will return the signal that was
/// received while no task was waiting on it.
///
/// # Failure
///
/// If this function fails to register a signal handler, then an error will
/// be raised on the `io_error` condition and the function will return
/// false.
pub fn register(&mut self, signum: Signum) -> bool {
if self.handles.contains_key(&signum) {
return true; // self is already listening to signum, so succeed
}
do with_local_io |io| {
match io.signal(signum, self.chan.clone()) {
Ok(w) => {
self.handles.insert(signum, w);
Some(())
},
Err(ioerr) => {
io_error::cond.raise(ioerr);
None
}
}
}.is_some()
}
/// Unregisters a signal. If this listener currently had a handler
/// registered for the signal, then it will stop receiving any more
/// notification about the signal. If the signal has already been received,
/// it may still be returned by `recv`.
pub fn unregister(&mut self, signum: Signum) {
self.handles.pop(&signum);
}
}
#[cfg(test)]
mod test {
use libc;
use io::timer;
use super::{Listener, Interrupt};
use comm::{GenericPort, Peekable};
// kill is only available on Unixes
#[cfg(unix)]
fn sigint() {
unsafe {
libc::funcs::posix88::signal::kill(libc::getpid(), libc::SIGINT);
}
}
#[test] #[cfg(unix, not(target_os="android"))] // FIXME(#10378)
fn test_io_signal_smoketest() {
let mut signal = Listener::new();
signal.register(Interrupt);
sigint();
timer::sleep(10);
match signal.port.recv() {
Interrupt => (),
s => fail!("Expected Interrupt, got {:?}", s),
}
}
#[test] #[cfg(unix, not(target_os="android"))] // FIXME(#10378)
fn test_io_signal_two_signal_one_signum() {
let mut s1 = Listener::new();
let mut s2 = Listener::new();
s1.register(Interrupt);
s2.register(Interrupt);
sigint();
timer::sleep(10);
match s1.port.recv() {
Interrupt => (),
s => fail!("Expected Interrupt, got {:?}", s),
}
match s2.port.recv() {
Interrupt => (),
s => fail!("Expected Interrupt, got {:?}", s),
}
}
#[test] #[cfg(unix, not(target_os="android"))] // FIXME(#10378)
fn test_io_signal_unregister() {
let mut s1 = Listener::new();
let mut s2 = Listener::new();
s1.register(Interrupt);
s2.register(Interrupt);
s2.unregister(Interrupt);
sigint();
timer::sleep(10);
if s2.port.peek() {
fail!("Unexpected {:?}", s2.port.recv());
}
}
#[cfg(windows)]
#[test]
fn test_io_signal_invalid_signum() {
use io;
use super::User1;
let mut s = Listener::new();
let mut called = false;
do io::io_error::cond.trap(|_| {
called = true;
}).inside {
if s.register(User1) {
fail!("Unexpected successful registry of signum {:?}", User1);
}
}
assert!(called);
}
}