Question

I have a logical problem i am not sure how to solve.. Basically i have a program that starts threads based on a numericUpDown value, if the user selects 5 in the numericUpDown box 5 threads will start.

The problem is that the user also has a listbox they can fill in with info, which will be used in the threads..

So what i want to be able to do in my loop instead of looping it 5 times from the numericUpDown value is if; lets say the user enteres 10 items in the listBox, and selects to use 5 threads.. i then want all the listBox items to be queued but only have 5 run at a time..

How would i accomplish this?

Oh if it matters this is how i start my threads:

                Thread thread = new Thread(() => doTask(numeret));
                thread.IsBackground = true;
                thread.Start();

Answer 1

I believe you wish to use a ThreadPool, as explained here:

http://msdn.microsoft.com/en-us/library/system.threading.threadpool.aspx

You need to specify the number of threads to use, and then use ThreadPool.QueueUserWorkItem to queue your tasks.

Alternatively, you can use the parallel extensions to LinQ to perform asynchronous tasks (not the same as multithreading) – and specify the .MaxDegreesOfParalallism() value (which only sets the upper maximum)

itemsToProcess.AsParallel().MaxDegreesOfParalallism(numThreads).ForAll(item =>
{
    doTask(item);
});