Question

i want to start 6 Threads asynchronously, paused them and resume synchronously…

it should work like this one:

1. Thread 1 starting (thr1.start())
2. Thread 1 some progress (getting mac-adresses from txt-file, initializing com-objects)
3. Thread 1 paused (paused until all threads did the same as thread 1)
4. Thread 2 starting
5. Thread 2 some progress
6. Thread 2 paused
7. Thread 3 starting
8. Thread 3 some progress
9. Thread 3 paused
10. …
11. after all 6 thread paused, they should resume all..

i tried with 6 simple boolean flags and wait until they are all true but thats quite a bit dirty…

any ideas?

EDIT (better visualization):

Thr1 | Initiliazing |waiting      |waiting      | Resuming
Thr2 | waiting      |Initiliazing |waiting      | Resuming
Thr3 | waiting      |waiting      |Initiliazing | Resuming
...           

thanks and greetz,
flux

Answer 1

You want some sort of synchronization – a ManualResetEvent for each thread sounds likely, depending on your thread functions.

---

EDIT: Thanks for your updates – here’s a basic example:

// initComplete is set by each worker thread to tell StartThreads to continue
//     with the next thread
//
// allComplete is set by StartThreads to tell the workers that they have all
//     initialized and that they may all resume


void StartThreads()
{
    var initComplete = new AutoResetEvent( false );
    var allComplete = new ManualResetEvent( false );

    var t1 = new Thread( () => ThreadProc( initComplete, allComplete ) );
    t1.Start();
    initComplete.WaitOne();

    var t2 = new Thread( () => ThreadProc( initComplete, allComplete ) );
    t2.Start();
    initComplete.WaitOne();

    // ...

    var t6 = new Thread( () => ThreadProc( initComplete, allComplete ) );
    t6.Start();
    initComplete.WaitOne();

    // allow all threads to continue
    allComplete.Set();
}


void ThreadProc( AutoResetEvent initComplete, WaitHandle allComplete )
{
    // do init

    initComplete.Set(); // signal init is complete on this thread

    allComplete.WaitOne(); // wait for signal that all threads are ready

    // resume all
}

Note that the StartThreads method will block while the threads initialize – this may or may not be a problem.