1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
// 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.
//! A small module implementing a simple "runtime" used for bootstrapping a rust
//! scheduler pool and then interacting with it.
use std::any::Any;
use std::cast;
use std::rt::Runtime;
use std::rt::local::Local;
use std::rt::rtio;
use std::rt::task::{Task, BlockedTask};
use std::task::TaskOpts;
use std::unstable::mutex::NativeMutex;
struct SimpleTask {
lock: NativeMutex,
awoken: bool,
}
impl Runtime for SimpleTask {
// Implement the simple tasks of descheduling and rescheduling, but only in
// a simple number of cases.
fn deschedule(mut ~self, times: uint, mut cur_task: ~Task,
f: |BlockedTask| -> Result<(), BlockedTask>) {
assert!(times == 1);
let me = &mut *self as *mut SimpleTask;
let cur_dupe = &*cur_task as *Task;
cur_task.put_runtime(self);
let task = BlockedTask::block(cur_task);
// See libnative/task.rs for what's going on here with the `awoken`
// field and the while loop around wait()
unsafe {
let guard = (*me).lock.lock();
(*me).awoken = false;
match f(task) {
Ok(()) => {
while !(*me).awoken {
guard.wait();
}
}
Err(task) => { cast::forget(task.wake()); }
}
drop(guard);
cur_task = cast::transmute(cur_dupe);
}
Local::put(cur_task);
}
fn reawaken(mut ~self, mut to_wake: ~Task) {
let me = &mut *self as *mut SimpleTask;
to_wake.put_runtime(self);
unsafe {
cast::forget(to_wake);
let guard = (*me).lock.lock();
(*me).awoken = true;
guard.signal();
}
}
// These functions are all unimplemented and fail as a result. This is on
// purpose. A "simple task" is just that, a very simple task that can't
// really do a whole lot. The only purpose of the task is to get us off our
// feet and running.
fn yield_now(~self, _cur_task: ~Task) { fail!() }
fn maybe_yield(~self, _cur_task: ~Task) { fail!() }
fn spawn_sibling(~self, _cur_task: ~Task, _opts: TaskOpts, _f: proc()) {
fail!()
}
fn local_io<'a>(&'a mut self) -> Option<rtio::LocalIo<'a>> { None }
fn stack_bounds(&self) -> (uint, uint) { fail!() }
fn can_block(&self) -> bool { true }
fn wrap(~self) -> ~Any { fail!() }
}
pub fn task() -> ~Task {
let mut task = ~Task::new();
task.put_runtime(~SimpleTask {
lock: unsafe {NativeMutex::new()},
awoken: false,
});
return task;
}
|
