switch.rs

extern mod extra;

use std::comm;
use std::io;

use extra::time;

fn to_us(ts: &time::Timespec) -> u64 {
    ts.sec as u64 * 1000000 + ((ts.nsec / 1000) as u64)
}

fn now_us() -> u64 {
    to_us(&time::get_time())
}

// execute as RUST_THREADS=1 ./switch
// result is about 2us per switch
fn main() {
    let (port1, chan1): (Port<int>, Chan<int>) = comm::stream();
    let (port2, chan2): (Port<int>, Chan<int>) = comm::stream();

    let steps = 100000;

    do spawn || {
        let mut i = 0;
        while i < steps {
            chan2.send(port1.recv());
            i += 1;
        }
    };

    let start = now_us();

    let mut i = 0;
    while i < steps {
        chan1.send(i as int);
        port2.recv();
        i += 1;
    }

    let d = now_us() - start;
    let per_step = d * 1000 / steps / 2;
    io::println(per_step.to_str() + "ns");
}