Top "Dispatch-async" questions

Understanding dispatch_async

I have question around this code dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ NSData* data = [NSData dataWithContentsOfURL: …

objective-c asynchronous dispatch-async

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 …

swift grand-central-dispatch dispatch-async swift3 libdispatch

iPhone - Grand Central Dispatch main thread

I have been using with success, grand central dispatch in my apps, but I was wondering what is the real …

ios concurrency grand-central-dispatch dispatch-async

Does dispatch_async(dispatch_get_main_queue(), ^{...}); wait until done?

I have a scenario in my app, where I want to do some time consuming task which consists of some …

ios objective-c multithreading grand-central-dispatch dispatch-async

dispatch_async and block in iOS

What this piece of code mean? dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ TMBaseParser *parser=[[TMBaseParser alloc] …

ios dispatch-async

Does using dispatch_get_main_queue() mean that my code will be on the main thread?

Does the following code run on the main thread? Does "main queue" refer to the main thread? dispatch_async(dispatch_…

objective-c grand-central-dispatch dispatch-async

Swift 3 warning for dispatch async

I have this code: DispatchQueue.global(priority: DispatchQueue.GlobalQueuePriority.default).async { let url = URL(string: itemImageURL ) let data = try? Data(…

ios warnings swift3 dispatch-async deprecation-warning

DispatchQueue crashing with main.sync in Swift

Please explain to me why I am getting this crash? Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) …

ios swift event-dispatch-thread dispatch-async

How to convert (OS_dispatch_data *) 5018112 bytes into NSData to put into UIImage

I've been looking for an answer to this and some seem like they might be what I need but I'm …

objective-c opencv uiimage dispatch-async

Crashed: com.apple.root.default-qos

I have a fairly simple app that parses a RSS feed and shows it's content in a table view. It's …

ios swift multithreading grand-central-dispatch dispatch-async