1 // Copyright 2013 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
4 //
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
10
11 //! Implementation of running at_exit routines
12 //!
13 //! Documentation can be found on the `rt::at_exit` function.
14
15 use cast;
16 use iter::Iterator;
17 use kinds::Send;
18 use mem;
19 use option::{Some, None};
20 use owned::Box;
21 use ptr::RawPtr;
22 use unstable::sync::Exclusive;
23 use slice::OwnedVector;
24 use vec::Vec;
25
26 type Queue = Exclusive<Vec<proc():Send>>;
27
28 // You'll note that these variables are *not* atomic, and this is done on
29 // purpose. This module is designed to have init() called *once* in a
30 // single-task context, and then run() is called only once in another
31 // single-task context. As a result of this, only the `push` function is
32 // thread-safe, and it assumes that the `init` function has run previously.
33 static mut QUEUE: *mut Queue = 0 as *mut Queue;
34 static mut RUNNING: bool = false;
35
36 pub fn init() {
37 unsafe {
38 rtassert!(!RUNNING);
39 rtassert!(QUEUE.is_null());
40 let state: Box<Queue> = box Exclusive::new(vec!());
41 QUEUE = cast::transmute(state);
42 }
43 }
44
45 pub fn push(f: proc():Send) {
46 unsafe {
47 rtassert!(!RUNNING);
48 rtassert!(!QUEUE.is_null());
49 let state: &mut Queue = cast::transmute(QUEUE);
50 let mut f = Some(f);
51 state.with(|arr| {
52 arr.push(f.take_unwrap());
53 });
54 }
55 }
56
57 pub fn run() {
58 let vec = unsafe {
59 rtassert!(!RUNNING);
60 rtassert!(!QUEUE.is_null());
61 RUNNING = true;
62 let state: Box<Queue> = cast::transmute(QUEUE);
63 QUEUE = 0 as *mut Queue;
64 let mut vec = None;
65 state.with(|arr| {
66 vec = Some(mem::replace(arr, vec!()));
67 });
68 vec.take_unwrap()
69 };
70
71
72 for f in vec.move_iter() {
73 f();
74 }
75 }