Concurrency1.rs

use std::thread;
use std::sync::Arc;
use std::sync::atomic::AtomicI32; 
use std::sync::atomic::Ordering;
fn main() {
    let total = add(46, -4);
    println!("total = {};", total)
}

fn add(n1: i32, n2: i32) -> i32 {
    let sum = Arc::new(AtomicI32::new(n1));
    let (count, increment) = if n2 > 0 {(n2, 1)} else {(-n2, -1)}; 
    let mut handles = vec![];
    
    for _ in 0..count {
    let inner_sum = Arc::clone(&sum);
        handles.push(
            thread::spawn(move ||{
                inner_sum.fetch_add(increment, Ordering::SeqCst);
            })
        )
    }
    for handle in handles{
        handle.join().unwrap();
    }
    sum.load(Ordering::SeqCst)
}