extern crate timely;

use timely::dataflow::channels::pact::Pipeline;
use timely::dataflow::operators::{Feedback, ConnectLoop};
use timely::dataflow::operators::generic::operator::Operator;

fn main() {

    let iterations = std::env::args().nth(1).unwrap().parse::<usize>().unwrap_or(1_000_000);

    timely::execute_from_args(std::env::args().skip(2), move |worker| {

        worker.dataflow(move |scope| {
            let (handle, stream) = scope.feedback::<usize>(1);
            stream.unary_notify(
                Pipeline,
                "Barrier",
                vec![0],
                move |_, _, notificator| {
                    while let Some((cap, _count)) = notificator.next() {
                        let time = *cap.time() + 1;
                        if time < iterations {
                            notificator.notify_at(cap.delayed(&time));
                        }
                    }
                }
            )
            .connect_loop(handle);
        });
    }).unwrap(); // asserts error-free execution;
}