SwitchToThread/Thread.Yield vs. Thread.Sleep(0) vs. Thead.Sleep(1)

Question

I am trying to write the ultimate \"Yield\" method to yield the current time slice to other threads. So far I have found that there are several different ways to make the th

Answer 1

In addition to other answers, here are some profiling numbers.

(!) Don't take this profiling too seriously! Is made just to illustrate above answers in numbers and roughly compare magnitude of values.

static void Profile(Action func)
    {
        var sw = new Stopwatch();
        var beginTime = DateTime.Now;
        ulong count = 0;
        while (DateTime.Now.Subtract(beginTime).TotalSeconds < 5)
        {
            sw.Start();
            func();
            sw.Stop();
            count++;
        }
        Console.WriteLine($"Made {count} iterations in ~5s. Total sleep time {sw.ElapsedMilliseconds}[ms]. Mean time = {sw.ElapsedMilliseconds/(double) count} [ms]");
    }

        Profile(()=>Thread.Sleep(0));
        Profile(()=>Thread.Sleep(1));
        Profile(()=>Thread.Yield());
        Profile(()=>Thread.SpinWait(1));

The results of spinning loops for ~5s:

Function   | CPU % | Iters made |  Total sleep  | Invoke 
           |       |            |  time [ms]    | time [ms]
===================================================================== 
Sleep(0)   | 100 0 | 2318103    | 482           | 0.00020
Sleep(1)   |  6  0 | 4586       | 5456          | 1.08971 
Yield()    | 100 0 | 2495220    | 364           | 0.00010
SpinWait(1)| 100 0 | 2668745    | 81            | 0.00003

Made with Mono 4.2.3 x86_64