olbrichj

let operationQueue: OperationQueue = OperationQueue()

olbrichj

OperationQueue.main

olbrichj

func executeOnMain() {
  if !Thread.isMainThread {
    DispatchQueue.main.async(execute: {() -> Void in
      executeOnMain()
    })
    return
  }
  
  // do something
}

olbrichj

let lock = self

objc_sync_enter(lock)
closure()
objc_sync_exit(lock)

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let s = DispatchSemaphore(value: 1)
_ = s.wait(timeout: DispatchTime.distantFuture)
// do something
s.signal()

olbrichj

var m = pthread_mutex_t()
pthread_mutex_lock(&m)
// do something
pthread_mutex_unlock(&m)

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let lock = NSLock()
lock.lock()
//do something
lock.unlock()

olbrichj

operation2.addDependency(operation1) //execute operation1 before operation2

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class CustomOperation: Operation {
    override func main() {
        guard isCancelled == false else {
            finish(true)
            return
        }
        
        // Do something
        
        finish(true)

olbrichj

let operationQueue: OperationQueue = OperationQueue()
operationQueue.addOperations([operation1], waitUntilFinished: false)