Can I use Task.Delay as a timer?

Question

I want to execute some code on each second. The code I am using now is:

Task.Run((Action)ExecuteSomething);

And ExecuteSomething() is defined as below:

 private void ExecuteSomething()         {             Task.Delay(1000).ContinueWith(                t =>                {                    //Do something.                     ExecuteSomething();                });         } 

Does this method block a thread? Or should I use Timer class in C#? And it seems Timer also dedicates a separate thread for execution (?)

Answer 1

Task.Delay uses Timer internally

With Task.Delay you can make your code a little-bid clearer than with Timer. And using async-await will not block the current thread (UI usually).

public async Task ExecuteEverySecond(Action execute) {     while(true)     {         execute();         await Task.Delay(1000);     } } 

From source code: Task.Delay

// on line 5893 // ... and create our timer and make sure that it stays rooted. if (millisecondsDelay != Timeout.Infinite) // no need to create the timer if it's an infinite timeout {     promise.Timer = new Timer(state => ((DelayPromise)state).Complete(), promise, millisecondsDelay, Timeout.Infinite);     promise.Timer.KeepRootedWhileScheduled(); }  // ... 

Answer 2

Microsoft's Reactive Framework is ideal for this. Just NuGet "System.Reactive" to get the bits. Then you can do this:

IDisposable subscription =     Observable         .Interval(TimeSpan.FromSeconds(1.0))         .Subscribe(x => execute()); 

When you want to stop the subscription just call subscription.Dispose(). On top of this the Reactive Framework can offer far more power than Tasks or basic Timers.