Async

More easier to use GCD in Swift.

This is heavily inspired by Async, a very simple, light but powerful project.

I removed some of the features to make it more simple but enough to use, and rewrote the AsyncGroup part to make it more easier to support async operations.

Simple to use:

DispatchQueue.main.async {
   // to do something
}

Async.main {
  // to do something
}

DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
    // to do something after 3 seconds
}
Async.main(after: 3) {
    // to do something after 3 seconds
}

Custom queue

only support concurrent queue for now

Async.custom(label: "job", after: 3) {
    Logger.log("do something on a custom queue", event: .debug)
}

Chainable

Async.main(after: 3) {
    Logger.log("do some job...", event: .debug)
}.main {
    Logger.log("job finished.", event: .debug)
}

Cancelable

Note: only when the block hasn't already begun running that can be cancelled.

let job1 = Async.main {
    Logger.log("start to do some heavy jobs..", event: .debug)
    for i in 0 ... 1000000 {
        // do some heavy jobs
        if i % 100000 == 0 {
            Logger.log("job \(i)", event: .debug)
        }
    }
    Logger.log("all heavy jobs are done", event: .debug)
}
let job2 = job1.global {
    Logger.log("this will be cancelled", event: .debug)
}

Async.main {
    job1.cancel() // can't be cancelled because it's running
    job2.cancel() // will be cancelled
}.custom(label: "cancel job") {
    Logger.log("all job canceld. [\(Thread.current)]", event: .debug)
}

Async Group

Support async operations

let group = AsyncGroup()
group.start { (job) in
    Logger.log("start job1...", event: .debug)
    Async.main(after: 3, {
        job.finish() // call finish() when async operation is done.
        Logger.log("job1 done.", event: .debug)
    })
}
group.start { (job) in
    Logger.log("start job2...", event: .debug)
    Async.main(after: 5, {
        job.finish()
        Logger.log("job2 done.", event: .debug)
    })
}
group.finished { // will be called when all async jobs are done.
    Logger.log("all jobs are done.", event: .debug)
}