rust/src/libstd/rt/at_exit_imp.rs
2015-03-18 16:32:32 -07:00

73 lines
2.1 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.
//! Implementation of running at_exit routines
//!
//! Documentation can be found on the `rt::at_exit` function.
use boxed;
use boxed::Box;
use vec::Vec;
use thunk::Thunk;
use sys_common::mutex::{Mutex, MUTEX_INIT};
type Queue = Vec<Thunk<'static>>;
// NB these are specifically not types from `std::sync` as they currently rely
// on poisoning and this module needs to operate at a lower level than requiring
// the thread infrastructure to be in place (useful on the borders of
// initialization/destruction).
static LOCK: Mutex = MUTEX_INIT;
static mut QUEUE: *mut Queue = 0 as *mut Queue;
unsafe fn init() {
if QUEUE.is_null() {
let state: Box<Queue> = box Vec::new();
QUEUE = boxed::into_raw(state);
} else {
// can't re-init after a cleanup
rtassert!(QUEUE as uint != 1);
}
// FIXME: switch this to use atexit as below. Currently this
// segfaults (the queue's memory is mysteriously gone), so
// instead the cleanup is tied to the `std::rt` entry point.
//
// ::libc::atexit(cleanup);
}
pub fn cleanup() {
unsafe {
LOCK.lock();
let queue = QUEUE;
QUEUE = 1 as *mut _;
LOCK.unlock();
// make sure we're not recursively cleaning up
rtassert!(queue as uint != 1);
// If we never called init, not need to cleanup!
if queue as uint != 0 {
let queue: Box<Queue> = Box::from_raw(queue);
for to_run in *queue {
to_run.invoke(());
}
}
}
}
pub fn push(f: Thunk<'static>) {
unsafe {
LOCK.lock();
init();
(*QUEUE).push(f);
LOCK.unlock();
}
}