Question

I want to implement a multithread system (two threads will do) and I followed a tutorial

    Thread t1 = new Thread(new ThreadStart(threadA));
    Thread t2 = new Thread(new ThreadStart(threadB));
    t1.Start();
    t2.Start();

The output is unexpected for me as it shows:
“threadA”
“threadA”
“threadA”
“threadB”
“threadB”
“threadB”.
Is something wrong with my code? Many thanks.

Answer 1

This is happening because in the time that it takes for you to go from t1.Start() to t2.Start(), your t1 has already completed.

Try something like this if you want to see your code alternate a little

Thread t1 = new Thread(
    new ThreadStart(()=>
    {
        for(int i = 0; i < 3; i++)
        {
            System.Console.WriteLine("ThreadA");    
            Thread.Sleep(3000)
        }
    }));
Thread t2 = new Thread(
    new ThreadStart(()=>
    {
        for(int i = 0; i < 3; i++)
        {
            System.Console.WriteLine("ThreadB");    
            Thread.Sleep(1000)
        }
    }));
t1.Start();
t2.Start();

It should print something like this:

ThreadA
ThreadB
ThreadB
ThreadA
ThreadB
ThreadA

However, this just shows that you cannot guarantee any order when it comes to threading.