Beginnings of a GCD wrapper in swift

dispatch.swift

import Foundation

class dispatch
{
    class async
    {
        class func bg(block: dispatch_block_t) {
            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), block)
        }

        class func main(block: dispatch_block_t) {
            dispatch_async(dispatch_get_main_queue(), block)
        }
    }

    class sync
    {
        class func bg(block: dispatch_block_t) {
            dispatch_sync(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), block)
        }

        class func main(block: dispatch_block_t) {
            if NSThread.isMainThread {
                block()
            }
            else {
                dispatch_sync(dispatch_get_main_queue(), block)
            }
        }
    }

    // after by @stanislavfeldman
    class after {
        class func bg(when: dispatch_time_t, block: dispatch_block_t) {
            dispatch_after(when, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)!, block)
        }
        
        class func main(when: dispatch_time_t, block: dispatch_block_t) {
            dispatch_after(when, dispatch_get_main_queue(), block)
        }
    }
}

ViewController.swift

import UIKit
import QuartzCore

class ViewController: UIViewController {

    @IBOutlet weak var label: UILabel
    @IBOutlet weak var counter: UILabel

    override func viewDidLoad() {
        super.viewDidLoad()

        dispatch.async.bg {
            var count = 0;
            for index in 0..10000000 {
                dispatch.sync.main {
                    self.counter.text = "\(index)"
                }
            }
        }
    }

    @IBAction func clickety() {
        label.text = NSDate.date().description
    }
}

Ah yes. Fixed. ^^

赞(Good) !

Inferis, take a look at my fork https://gist.github.com/stanislavfeldman/0f37794b369eb6da98cc
I added after blocks.

@Inferis I have a variation on your wrapper that adds more queues (interactive, user, utility) and implements (optional) safe sync for all queues (probably not needed beside main). I needed to reverse the call order to make this manageable:

dispatch.main.sync {print("hello possible deadlock")}
dispatch.utility.async {print("hello")}
dispatch.main.safeSync {print("hello from the main thread")}
dispatch.main.after(2.5) {print("in main after 2.5 seconds")}

@stanfeldman I don't think your "after" methods do what you think they do. dispatch_after requires argument prepared with dispatch_time.

https://gist.github.com/amw/9d62f247d0de3fa08e5facc59bc91037

I've added support for dispatch groups and blogged about my implementation.

http://adamwrobel.com/blog/2016/05/08/swift-gcd-wrapper/