rust/src/test/run-pass/task-comm-12.rs

// Copyright 2012 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.

extern mod std;

pub fn main() { test00(); }

fn start(&&task_number: int) { debug!("Started / Finished task."); }

fn test00() {
    let i: int = 0;
    let mut result = None;
    do task::task().future_result(|+r| { result = Some(move r); }).spawn {
        start(i)
    }

    // Sleep long enough for the task to finish.
    let mut i = 0;
    while i < 10000 {
        task::yield();
        i += 1;
    }

    // Try joining tasks that have already finished.
    option::unwrap(move result).recv();

    debug!("Joined task.");
}