Crate wg

wg

Golang like WaitGroup implementation for sync/async Rust.

Introduction

By default, blocking version WaitGroup is enabled.

If you are using tokio, you need to enable tokio feature in your Cargo.toml and use wg::tokio::AsyncWaitGroup.

If you are using other async runtime, you need to enbale future feature in your Cargo.toml and use wg::future::AsyncWaitGroup.

Sync

[dependencies]
wg = "0.8"

tokio

An async implementation for tokio runtime.

[dependencies]
wg = { version = "0.8", features = ["tokio"] }

future

A more generic async implementation.

[dependencies]
wg = { version = "0.8", features = ["future"] }

Instruction

Sync

use wg::WaitGroup;
use std::sync::Arc;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::time::Duration;
use std::thread::{spawn, sleep};

fn main() {
    let wg = WaitGroup::new();
    let ctr = Arc::new(AtomicUsize::new(0));

    for _ in 0..5 {
        let ctrx = ctr.clone();
        let t_wg = wg.add(1);
        spawn(move || {
            // mock some time consuming task
            sleep(Duration::from_millis(50));
            ctrx.fetch_add(1, Ordering::Relaxed);

            // mock task is finished
            t_wg.done();
        });
    }

    wg.wait();
    assert_eq!(ctr.load(Ordering::Relaxed), 5);
}

tokio

use wg::tokio::AsyncWaitGroup;
use std::sync::Arc;
use std::sync::atomic::{AtomicUsize, Ordering};
use tokio::{spawn, time::{sleep, Duration}};

#[tokio::main]
async fn main() {
    let wg = AsyncWaitGroup::new();
    let ctr = Arc::new(AtomicUsize::new(0));

    for _ in 0..5 {
        let ctrx = ctr.clone();
        let t_wg = wg.add(1);
        spawn(async move {
            // mock some time consuming task
            sleep(Duration::from_millis(50)).await;
            ctrx.fetch_add(1, Ordering::Relaxed);

            // mock task is finished
            t_wg.done();
        });
    }

    wg.wait().await;
    assert_eq!(ctr.load(Ordering::Relaxed), 5);
}

async-io

use wg::future::AsyncWaitGroup;
use std::sync::Arc;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::time::Duration;
use async_std::task::{spawn, block_on, sleep};

fn main() {
    block_on(async {
        let wg = AsyncWaitGroup::new();
        let ctr = Arc::new(AtomicUsize::new(0));

        for _ in 0..5 {
            let ctrx = ctr.clone();
            let t_wg = wg.add(1);
            spawn(async move {
                // mock some time consuming task
                sleep(Duration::from_millis(50)).await;
                ctrx.fetch_add(1, Ordering::Relaxed);

                // mock task is finished
                t_wg.done();
            });
        }

        wg.wait().await;
        assert_eq!(ctr.load(Ordering::Relaxed), 5);
    });
}

Acknowledgements

• Inspired by Golang sync.WaitGroup and crossbeam_utils::WaitGroup.

License

^{Licensed under either of Apache License, Version 2.0 or MIT license at your option.} _{Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.}

Modules

• futurefuture
  AsyncWaitGroup for futures.
• tokiotokio
  AsyncWaitGroup for tokio runtime.

Structs

• WaitGroupstd
  A WaitGroup waits for a collection of threads to finish. The main thread calls add to set the number of thread to wait for. Then each of the goroutines runs and calls Done when finished. At the same time, Wait can be used to block until all goroutines have finished.