rust/src/libnative/bookkeeping.rs
Huon Wilson b87ed605c0 std: Rename unstable::mutex::Mutex to StaticNativeMutex.
This better reflects its purpose and design.
2014-02-16 10:13:56 +11:00

51 lines
1.6 KiB
Rust

// Copyright 2013-2014 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.
//! 1:1 Task bookkeeping
//!
//! This module keeps track of the number of running 1:1 tasks so that entry
//! points with libnative know when it's possible to exit the program (once all
//! tasks have exited).
//!
//! The green counterpart for this is bookkeeping on sched pools.
use std::sync::atomics;
use std::unstable::mutex::{StaticNativeMutex, NATIVE_MUTEX_INIT};
static mut TASK_COUNT: atomics::AtomicUint = atomics::INIT_ATOMIC_UINT;
static mut TASK_LOCK: StaticNativeMutex = NATIVE_MUTEX_INIT;
pub fn increment() {
let _ = unsafe { TASK_COUNT.fetch_add(1, atomics::SeqCst) };
}
pub fn decrement() {
unsafe {
if TASK_COUNT.fetch_sub(1, atomics::SeqCst) == 1 {
let mut guard = TASK_LOCK.lock();
guard.signal();
}
}
}
/// Waits for all other native tasks in the system to exit. This is only used by
/// the entry points of native programs
pub fn wait_for_other_tasks() {
unsafe {
{
let mut guard = TASK_LOCK.lock();
while TASK_COUNT.load(atomics::SeqCst) > 0 {
guard.wait();
}
}
TASK_LOCK.destroy();
}
}