rust/src/librustuv/idle.rs

// 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.

use std::libc::c_int;

use uvll;
use super::{Watcher, Loop, NativeHandle, IdleCallback, status_to_maybe_uv_error};

pub struct IdleWatcher(*uvll::uv_idle_t);
impl Watcher for IdleWatcher { }

impl IdleWatcher {
    pub fn new(loop_: &mut Loop) -> IdleWatcher {
        unsafe {
            let handle = uvll::malloc_handle(uvll::UV_IDLE);
            assert!(handle.is_not_null());
            assert_eq!(uvll::idle_init(loop_.native_handle(), handle), 0);
            let mut watcher: IdleWatcher = NativeHandle::from_native_handle(handle);
            watcher.install_watcher_data();
            return watcher
        }
    }

    pub fn start(&mut self, cb: IdleCallback) {
        {
            let data = self.get_watcher_data();
            data.idle_cb = Some(cb);
        }

        unsafe {
            assert_eq!(uvll::idle_start(self.native_handle(), idle_cb), 0)
        }
    }

    pub fn restart(&mut self) {
        unsafe {
            assert!(self.get_watcher_data().idle_cb.is_some());
            assert_eq!(uvll::idle_start(self.native_handle(), idle_cb), 0)
        }
    }

    pub fn stop(&mut self) {
        // NB: Not resetting the Rust idle_cb to None here because `stop` is
        // likely called from *within* the idle callback, causing a use after
        // free

        unsafe {
            assert_eq!(uvll::idle_stop(self.native_handle()), 0);
        }
    }
}

impl NativeHandle<*uvll::uv_idle_t> for IdleWatcher {
    fn from_native_handle(handle: *uvll::uv_idle_t) -> IdleWatcher {
        IdleWatcher(handle)
    }
    fn native_handle(&self) -> *uvll::uv_idle_t {
        match self { &IdleWatcher(ptr) => ptr }
    }
}

extern fn idle_cb(handle: *uvll::uv_idle_t, status: c_int) {
    let mut idle_watcher: IdleWatcher = NativeHandle::from_native_handle(handle);
    let data = idle_watcher.get_watcher_data();
    let cb: &IdleCallback = data.idle_cb.get_ref();
    let status = status_to_maybe_uv_error(status);
    (*cb)(idle_watcher, status);
}

#[cfg(test)]
mod test {

    use Loop;
    use super::*;
    use std::unstable::run_in_bare_thread;

    #[test]
    #[ignore(reason = "valgrind - loop destroyed before watcher?")]
    fn idle_new_then_close() {
        do run_in_bare_thread {
            let mut loop_ = Loop::new();
            let idle_watcher = { IdleWatcher::new(&mut loop_) };
            idle_watcher.close(||());
        }
    }

    #[test]
    fn idle_smoke_test() {
        do run_in_bare_thread {
            let mut loop_ = Loop::new();
            let mut idle_watcher = { IdleWatcher::new(&mut loop_) };
            let mut count = 10;
            let count_ptr: *mut int = &mut count;
            do idle_watcher.start |idle_watcher, status| {
                let mut idle_watcher = idle_watcher;
                assert!(status.is_none());
                if unsafe { *count_ptr == 10 } {
                    idle_watcher.stop();
                    idle_watcher.close(||());
                } else {
                    unsafe { *count_ptr = *count_ptr + 1; }
                }
            }
            loop_.run();
            loop_.close();
            assert_eq!(count, 10);
        }
    }

    #[test]
    fn idle_start_stop_start() {
        do run_in_bare_thread {
            let mut loop_ = Loop::new();
            let mut idle_watcher = { IdleWatcher::new(&mut loop_) };
            do idle_watcher.start |idle_watcher, status| {
                let mut idle_watcher = idle_watcher;
                assert!(status.is_none());
                idle_watcher.stop();
                do idle_watcher.start |idle_watcher, status| {
                    assert!(status.is_none());
                    let mut idle_watcher = idle_watcher;
                    idle_watcher.stop();
                    idle_watcher.close(||());
                }
            }
            loop_.run();
            loop_.close();
        }
    }
}