c# Threadpool - limit number of threads

c# multithreading threadpool
Bryan picture Bryan · Apr 27, 2012 · Viewed 53.2k times · Source

I am developing a console app.

I want to use a Threadpool to perform web downloads. Here is some fake code. 

 for (int loop=0; loop< 100; loop++)
 {
     ThreadPool.QueueUserWorkItem(new WaitCallback(GetPage), pageList[loop]);
 }


snip

private static void GetPage(object o)
{
    //get the page
}

How do I prevent my code from starting more than two (or ten, or whatever) simultaneous threads?

I have tried 

    ThreadPool.SetMaxThreads(1, 0);
    ThreadPool.SetMinThreads(1, 0);

But they seem to have no impact.

Answer

Brian Gideon picture Brian Gideon · Apr 27, 2012

I would use Parallel.For and set MaxDegreeOfParallelism accordingly.

Parallel.For(0, 1000, new ParallelOptions { MaxDegreeOfParallelism = 10 },
  i =>
  {
    GetPage(pageList[i]);
  });

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