91 lines
3.1 KiB
Rust
91 lines
3.1 KiB
Rust
// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! A small module implementing a simple "runtime" used for bootstrapping a rust
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//! scheduler pool and then interacting with it.
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use std::cast;
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use std::rt::Runtime;
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use std::rt::local::Local;
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use std::rt::rtio;
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use std::rt::task::{Task, BlockedTask};
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use std::task::TaskOpts;
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use std::unstable::mutex::NativeMutex;
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struct SimpleTask {
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lock: NativeMutex,
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awoken: bool,
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}
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impl Runtime for SimpleTask {
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// Implement the simple tasks of descheduling and rescheduling, but only in
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// a simple number of cases.
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fn deschedule(mut ~self, times: uint, mut cur_task: ~Task,
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f: |BlockedTask| -> Result<(), BlockedTask>) {
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assert!(times == 1);
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let me = &mut *self as *mut SimpleTask;
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let cur_dupe = &*cur_task as *Task;
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cur_task.put_runtime(self as ~Runtime);
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let task = BlockedTask::block(cur_task);
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// See libnative/task.rs for what's going on here with the `awoken`
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// field and the while loop around wait()
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unsafe {
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let mut guard = (*me).lock.lock();
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(*me).awoken = false;
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match f(task) {
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Ok(()) => {
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while !(*me).awoken {
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guard.wait();
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}
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}
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Err(task) => { cast::forget(task.wake()); }
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}
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drop(guard);
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cur_task = cast::transmute(cur_dupe);
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}
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Local::put(cur_task);
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}
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fn reawaken(mut ~self, mut to_wake: ~Task) {
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let me = &mut *self as *mut SimpleTask;
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to_wake.put_runtime(self as ~Runtime);
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unsafe {
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cast::forget(to_wake);
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let mut guard = (*me).lock.lock();
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(*me).awoken = true;
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guard.signal();
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}
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}
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// These functions are all unimplemented and fail as a result. This is on
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// purpose. A "simple task" is just that, a very simple task that can't
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// really do a whole lot. The only purpose of the task is to get us off our
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// feet and running.
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fn yield_now(~self, _cur_task: ~Task) { fail!() }
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fn maybe_yield(~self, _cur_task: ~Task) { fail!() }
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fn spawn_sibling(~self, _cur_task: ~Task, _opts: TaskOpts, _f: proc()) {
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fail!()
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}
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fn local_io<'a>(&'a mut self) -> Option<rtio::LocalIo<'a>> { None }
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fn stack_bounds(&self) -> (uint, uint) { fail!() }
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fn can_block(&self) -> bool { true }
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fn wrap(~self) -> ~Any { fail!() }
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}
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pub fn task() -> ~Task {
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let mut task = ~Task::new();
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task.put_runtime(~SimpleTask {
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lock: unsafe {NativeMutex::new()},
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awoken: false,
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} as ~Runtime);
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return task;
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}
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