Question

I have this simple code : (which i run in linqpad)

void Main()
{
    for ( int  i=0;i<10;i++)
     {
      int  tmp=i;
      new Thread (() =>doWork(tmp)).Start();
     }
}

 public void doWork( int h)
 {
 h.Dump();
 }

the int tmp=i; line is for capture variable – so each iteration will have its own value.

2 problems :

1) the numbers are not sequential , while thread execution is !

2) sometimes i get less than 10 numbers !

here are some executions outputs:

questions :

1) why case 1 is happening and how can i solve it ?

2) why case 2 is happening and how can i solve it ?

Answer 1

It should not be expected that they are sequential. Each thread gets priority as the kernel chooses. It might happen that they look sequential, purely by the nature of when each is started, but that is pure chance.

For ensuring that they all complete – mark each new thread as IsBackground = false, so that it keeps the executable alive. For example:

new Thread(() => doWork(tmp)) { IsBackground = false }.Start();