Question

I currently have a small console application that runs a number of Tasks (using Parallel.ForEach) and each one of these tasks creates sub-threads using ThreadPool.QueueUserWorkItem.

I would like the application to handle any exception thrown by these tasks/threads.

Will surrounding the Parallel.ForEach statement with try..catch work if the threads throw any errors or will they just die out?

EDIT: These sub-threads simulate users of the system. Refer to this question.

Answer 1

Surrounding the statement will not do the job. You can do something like this:

public static void Main(string[] args)
{             
    string[] files = System.IO.Directory.GetFiles(@".", "*.*");      

    Parallel.ForEach(files, x =>
    {
      try
      {
        MyAction(x);
      }
      catch(Exception ex)
      {
        Console.WriteLine(ex.ToString());
      }
    });        
}

static void MyAction(string x)
{      
  throw new ApplicationException("Testing: " + x);
}