Concurrency_Mpsc.rs

use std::thread;
use std::sync::mpsc;
fn main() {
    let total = add(46, -4);
    println!("total = {};", total)
}

fn add(n1: i32, n2: i32) -> i32 {
    let mut sum = n1;
    let (count, increment) = if n2 > 0 {(n2, 1)} else {(-n2, -1)};
    let mut handles = vec![];
    let (tx, rx) = mpsc::channel();
    
    for _ in 0..count {
        let tx_for_thread = tx.clone();
        handles.push(
            thread::spawn(move || {
                tx_for_thread.send(increment).unwrap();
            })
        );
    }
    for handle in handles { handle.join().unwrap(); }
    
    for _ in 0..count{
        sum += rx.recv().unwrap();
    }
    sum
}