rust message ring

gistfile1.rs

use task::spawn;
use pipes::{Chan, Port, stream};

fn main() {
  let mut n = 100;
  let m = 1000000;

  let mut (firstChan, leftPort): (Chan<int>, Port<int>) = stream();
  firstChan.send(m);
  let mut (rightChan, rightPort): (Chan<int>, Port<int>) = stream();
  startNode(leftPort, rightChan);

  loop {
    leftPort <- rightPort;
    let (newChan, newPort): (Chan<int>, Port<int>) = stream();
    rightChan <- newChan;
    rightPort <- newPort;
    startNode(leftPort, rightChan);
    n -= 1;
    if n <= 2 {
      break
    }
  }

  startNode(rightPort, firstChan);
}

fn startNode(port: Port<int>, chan: Chan<int>) {
  do spawn {
    loop {
      let rec = port.recv();
      io::println(fmt!("%d", rec));
      if rec == 0 {
        chan.send(0);
        break
      }
      chan.send(rec - 1);
    }
  }
}