gistfile1.rs

use std::thread;
use std::io::prelude::*;
use std::net::{TcpListener, TcpStream};
use std::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};

static CNT: AtomicUsize = ATOMIC_USIZE_INIT;
static BUF: &'static [u8] = &[1; 128 * 1024];

fn main() {
    let l = TcpListener::bind("127.0.0.1:13566").unwrap();

    let _t1 = thread::scoped(|| {
        for a in l.incoming() {
            let mut a = a.unwrap();
            loop {
                match a.write(BUF) {
                    Ok(..) => {}
                    Err(..) => break,
                }
            }
        }
    });
    let _t1 = thread::scoped(|| {
        let mut s = TcpStream::connect("127.0.0.1:13566").unwrap();
        let mut b = [0; 64 * 1024];
        loop {
            // for b in b.iter_mut() { *b = 0; }
            match s.read(&mut b) {
                Ok(n) => { CNT.fetch_add(n, Ordering::SeqCst); }
                Err(..) => break,
            }
        }
    });

    loop {
        extern { fn usleep(usec: usize); }
        unsafe { usleep(1000000); }
        println!("{}", CNT.swap(0, Ordering::SeqCst));
    }
}

not zeroed

$ ./foo
9722724299
9742516277
9742843851
9801236480
9838657536
9723379765
9679798219

zeroed

$ ./foo
7265430272 
7389052928 
7271350272 
7355170816 
7333019648 
7377256448 
7515996160 
7494172672 
7448887296