Dismissing View Controller not stopping Async Task

Question

I\'m using the following code to do some complex background operations from a newly launched view controller

 let globalQueue = DispatchQueue.global()
  glob         


        

Answer 1

Create the dispatch work item.

//create the dispatch work item
var disptachWorkItem:DispatchWorkItem?

Now put the complex task in dispatch work item.

dispatchWorkItem = DispatchWorkItem {
//Some complex job
}

Execute the Work on default global queue.

DispatchQueue.global().async(execute: dispatchWorkItem!)

You can find out when the viewController is being dismissed.

DispatchQueue.global.async {
dispatchWorkItem?.cancel()
}
presentingViewController?.dismissViewController(animated: true, completion: nil)