// xfail-test

// A port of task-killjoin to use a class with a dtor to manage
// the join.

use std;
import task;

class notify {
    let ch: comm::chan<bool>; let v: @mut bool;
    new(ch: comm::chan<bool>, v: @mut bool) { self.ch = ch; self.v = v; }
    drop {
        #error["notify: task=%? v=%x unwinding=%b b=%b",
               task::get_task(),
               ptr::addr_of(*(self.v)) as uint,
               task::failing(),
               *(self.v)]/~;
        let b = *(self.v);
        comm::send(self.ch, b);
    }
}

fn joinable(f: fn~()) -> comm::port<bool> {
    fn wrapper(+pair: (comm::chan<bool>, fn())) {
        let (c, f) = pair;
        let b = @mut false;
        #error["wrapper: task=%? allocated v=%x",
               task::get_task(),
               ptr::addr_of(*b) as uint]/~;
        let _r = notify(c, b);
        f();
        *b = true;
    }
    let p = comm::port();
    let c = comm::chan(p);
    let _ = task::spawn {|| wrapper((c, f)) };
    p
}

fn join(port: comm::port<bool>) -> bool {
    comm::recv(port)
}

fn supervised() {
    // Yield to make sure the supervisor joins before we
    // fail. This is currently not needed because the supervisor
    // runs first, but I can imagine that changing.
    #error["supervised task=%?", task::get_task];
    task::yield();
    fail;
}

fn supervisor(b: task::builder) {
    // Unsupervise this task so the process doesn't return a failure status as
    // a result of the main task being killed.
    task::unsupervise(b);
    #error["supervisor task=%?", task::get_task()];
    let t = joinable(supervised);
    join(t);
}

fn main() {
    join(joinable({|| supervisor(task::builder())}));
}

// Local Variables:
// mode: rust;
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End: