Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 567
  • Last Modified:

ThreadPool problem

Hi Experts,

I have a threadpool in my method queueing 3 methods:

private mymethod...
{
something to do before

ThreadPool.QueueUserWorkItem(new WaitCallback(MyMethod1));
ThreadPool.QueueUserWorkItem(new WaitCallback(MyMethod2));
ThreadPool.QueueUserWorkItem(new WaitCallback(MyMethod3));

something to do after
}

An exception is thrown because I must wait for those threads to be finished to "do something after".

Could you help me ?

Thanks in advance for your answers.
0
noulouk
Asked:
noulouk
  • 5
  • 2
1 Solution
 
gregoryyoungCommented:
sorry I missed your comment on the other question http://www.experts-exchange.com/Programming/Programming_Languages/Dot_Net/ASP_DOT_NET/Q_21110775.html

you would use the manual reset event object http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemthreadingmanualreseteventclasstopic.asp you would clear them ... then in your callbacks set the signal as complete ... in your page load, wait on the signals ... there is an example in the help that should help clear things up.
0
 
nouloukAuthor Commented:
I have always the same trouble (I'm new in threading)
Here is my code:

private void ThreadAll()
        {
            autoEvents = new AutoResetEvent[] {
                                                  new AutoResetEvent(false),
                                                  new AutoResetEvent(false),
                                                  new AutoResetEvent(false)};

            ThreadPool.QueueUserWorkItem(new WaitCallback(method1));
            ThreadPool.QueueUserWorkItem(new WaitCallback(method2));
            ThreadPool.QueueUserWorkItem(new WaitCallback(method3));

            WaitHandle.WaitAll(autoEvents);
        }

private void method1(object stateInfo)
        {
            ...

            autoEvents[0].Set();
        }

private void method2(object stateInfo)
        {
            ...

            autoEvents[1].Set();
        }

private void method3(object stateInfo)
        {
            ...

            autoEvents[2].Set();
        }

An exception is thrown and there is no code available for debugging my webpage !
0
 
gregoryyoungCommented:
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Threading;
namespace WebApplication2
{
      /// <summary>
      /// Summary description for WebForm1.
      /// </summary>
      public class WebForm1 : System.Web.UI.Page
      {
            private ManualResetEvent [] autoEvents;
            private void ThreadAll() {
                  autoEvents = new ManualResetEvent[] {
                                                                          new ManualResetEvent(false),
                                                                          new ManualResetEvent(false),
                                                                          new ManualResetEvent(false)};

                  ThreadPool.QueueUserWorkItem(new WaitCallback(method1));
                  ThreadPool.QueueUserWorkItem(new WaitCallback(method2));
                  ThreadPool.QueueUserWorkItem(new WaitCallback(method3));
                  this.Response.Write("Waiting for threads to complete " + DateTime.Now.ToString() + "\n" );
                  WaitHandle.WaitAll(autoEvents);
                  this.Response.Write("Threads completed " + DateTime.Now.ToString() + "\n" );
            }

            private void method1(object stateInfo) {
                        Thread.Sleep(3000);
                        autoEvents[0].Set();
            }

            private void method2(object stateInfo) {
                        Thread.Sleep(1000);
                        autoEvents[1].Set();
            }

            private void method3(object stateInfo) {
                        Thread.Sleep(5000);
                        autoEvents[2].Set();
            }
            private void Page_Load(object sender, System.EventArgs e) {
                  this.ThreadAll();
            }
            #region Web Form Designer generated code
            override protected void OnInit(EventArgs e)
            {
                  //
                  // CODEGEN: This call is required by the ASP.NET Web Form Designer.
                  //
                  InitializeComponent();
                  base.OnInit(e);
            }
            
            /// <summary>
            /// Required method for Designer support - do not modify
            /// the contents of this method with the code editor.
            /// </summary>
            private void InitializeComponent()
            {    
                  this.Load += new System.EventHandler(this.Page_Load);
            }
            #endregion
      }
}
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
gregoryyoungCommented:
you can catch the exception as a global excepton ...
0
 
nouloukAuthor Commented:
Thanks, do you want me to grade you more in ASP .Net or I can delete the question ?
0
 
gregoryyoungCommented:
honestly points and a dollar will get me a cup of coffee ... glad you got it :)
0
 
gregoryyoungCommented:
heh I guess my its ok didnt work:)
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

  • 5
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now