Wait until all threads finished their work in ThreadPool

Question

i have this code:

var list = new List();
for(int i=0;i<10;i++) list.Add(i); 
for(int i=0;i<10;i++)
{
     ThreadPool.QueueUserWorkItem(
             


        

Answer 1

The thread pool does not tell you when the thread has finished executing, so the work item must do it itself. I changed the code like this:

    var list = new List();
    ManualResetEvent[] handles = new ManualResetEvent[10];
    for (int i = 0; i < 10; i++) {
        list.Add(i);
        handles[i] = new ManualResetEvent(false);
    }
    for (int i = 0; i < 10; i++) {
        ThreadPool.QueueUserWorkItem(
         new WaitCallback(x =>
         {
             Console.WriteLine(x);
             handles[(int) x].Set();
         }), list[i]);
    }

    WaitHandle.WaitAll(handles);