Wait until swift for loop with asynchronous network requests finishes executing
I would like a for in loop to send off a bunch of network requests to firebase, then pass the data to a … Read more
grand-central-dispatch
Waiting until two async blocks are executed before starting another block
When using GCD, we want to wait until two async blocks are executed and done before moving on to the next steps of … Read more
In Swift how to call method with parameters on GCD main thread?
In my app I have a function that makes an NSRURLSession and sends out an NSURLRequest using sesh.dataTaskWithRequest(req, completionHandler: {(data, response, error) In … Read more
How do I dispatch_sync, dispatch_async, dispatch_after, etc in Swift 3, Swift 4, and beyond?
I have lots of code in Swift 2.x (or even 1.x) projects that looks like this: // Move to a background thread to … Read more
GCD to perform task in main thread
I have a callback which might come from any thread. When I get this callback, then I would like to perform a certain … Read more
Create singleton using GCD’s dispatch_once in Objective-C
If you can target iOS 4.0 or above Using GCD, is it the best way to create singleton in Objective-C (thread safe)? + … Read more
How to create dispatch queue in Swift 3
In Swift 2, I was able to create queue with the following code: let concurrentQueue = dispatch_queue_create(“com.swift3.imageQueue”, DISPATCH_QUEUE_CONCURRENT) But this doesn’t compile in … Read more
How do I write dispatch_after GCD in Swift 3, 4, and 5?
In Swift 2, I was able to use dispatch_after to delay an action using grand central dispatch: var dispatchTime: dispatch_time_t = dispatch_time(DISPATCH_TIME_NOW, Int64(0.1 … Read more
NSOperation vs Grand Central Dispatch
I’m learning about concurrent programming for iOS. So far I’ve read about NSOperation/NSOperationQueue and GCD. What are the reasons for using NSOperationQueue over … Read more
dispatch_after – GCD in Swift?
I’ve gone through the iBook from Apple, and couldn’t find any definition of it: Can someone explain the structure of dispatch_after? dispatch_after(<#when: dispatch_time_t#>, … Read more