rust/src/test/run-pass/acyclic-unwind.rs

// xfail-stage1
// xfail-stage2
// xfail-stage3
// -*- rust -*-

fn f(c: chan[int]) {
    type t = {_0: int, _1: int, _2: int};

    // Allocate a box.
    let x: @t = @{_0: 1, _1: 2, _2: 3};

    // Signal parent that we've allocated a box.
    c <| 1;


    while true {
        // spin waiting for the parent to kill us.
        log "child waiting to die...";

        // while waiting to die, the messages we are
        // sending to the channel are never received
        // by the parent, therefore this test cases drops
        // messages on the floor
        c <| 1;
    }
}


fn main() {
    let p: port[int] = port();
    spawn f(chan(p));
    let i: int;

    // synchronize on event from child.
    p |> i;

    log "parent exiting, killing child";
}