Crate atomic_waitgroup 

A waitgroup support async with advanced features

implemented with atomic operations to reduce locking.

Features & restrictions

• wait_to() supports waiting for a value >= zero

• wait() & wait_to() can be canceled wrapped by timeout or futures::select!.

• Assumes only one thread calls wait(). If multiple concurrent wait() is detected, will panic for this invalid usage.

• done() & wait() is allowed to called concurrently.

• add() & done() is allowed to called concurrently.

• Assumes add() and wait() are in the same thread.

Example

extern crate atomic_waitgroup;
use atomic_waitgroup::WaitGroup;
use tokio::runtime::Runtime;

let rt = Runtime::new().unwrap();
let wg = WaitGroup::new();
rt.block_on(async move {
    for i in 0..2 {
        let _guard = wg.add_guard();
        tokio::spawn(async move {
           // Do something
            drop(_guard);
        });
    }
    match tokio::time::timeout(
        tokio::time::Duration::from_secs(1),
        wg.wait_to(1)).await {
        Ok(_) => {
            assert!(wg.left() <= 1);
        }
        Err(_) => {
            println!("wg.wait_to(1) timeouted");
        }
    }
});

Structs

WaitGroup

WaitGroupGuard