Trouble with Thread.Sleep(0)

Question

I tried to test the context switch using Thread.Sleep(0) using this code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Threading;

namespace ThreadMethod
{
    class Program
    {
        public static void ThreadMethod()
        {
            for (int i = 0; i < 10; i++)
            {
                Console.WriteLine("ThreadProc: {0}", i);

                Thread.Sleep(0);
            }
        }
        static void Main(string[] args)
        {
            Thread t = new Thread(new ThreadStart(ThreadMethod));

            t.Start();

            for (int i = 0; i < 10; i++)
            {
                Console.WriteLine("Main Thread here!");

                Thread.Sleep(0);
            }



            t.Join();
        }
    }
}

but result was the following:

Main Thread here!
ThreadProc: 0
ThreadProc: 1
ThreadProc: 2
ThreadProc: 3
ThreadProc: 4
ThreadProc: 5
ThreadProc: 6
ThreadProc: 7
ThreadProc: 8
Main Thread here!
Main Thread here!
Main Thread here!
Main Thread here!
Main Thread here!
Main Thread here!
Main Thread here!
Main Thread here!
Main Thread here!
ThreadProc: 9

I am developing on Surface PRO 2. Is this behaviour due to a multicore system?

Answer 1

如果你想强制上下文切换，你应该给你的线程低优先级/使用Thread.Sleep(1) ，你也可以在类似的问题上阅读更多关于这个的内容： Thread.Sleep(0) : What is the normal behavior ?

Answer 2

I think what you're looking for is Thread.Yield . This will signal OS that the current thread doesn't need the CPU time anymore and will make the OS switch to another thread if one is waiting.

Answer 3

if you want context switch, try Thread.Sleep() with something other than Zero.

See this - have good answers