Question

unconditional thread abort

Asked by: Azmodan

I want to abort (kill) a thread no matter what. In the documentation it says that if the thread is in an unmanaged code portion when the ThreadAbortException is thrown, the system will rethrow it when managed code is executed. But what if the thread is stuck in an unmanaged method? how can I kill the thread?

(as a side note, Socket.Receive() appears to be unmanaged!!! )

here is a small sample that uses 2 threads that get hung in a socket.receive and cannot be aborted. (i wanted them to get hunged!). If the socket part is commented, it works!



using System;
using System.Threading;
using System.Net;
using System.Net.Sockets;

namespace ConsoleApplication2
{
      /// <summary>
      /// Summary description for Class1.
      /// </summary>
      ///

      class MyThread
      {
            public MyThread()
            {
            }

            public void run()
            {
                  int i=0;
                  int k=0;
                  Console.WriteLine("init thread " + this.GetHashCode());
                  while(true)
                  {
                        Console.WriteLine("thread " + this.GetHashCode() + " " + i++);
                        Thread.Sleep(1000);

                        //----begin socket part---
                        Socket sock = new Socket(AddressFamily.InterNetwork,SocketType.Dgram,ProtocolType.Udp);

                                                      //bogus address, nothigs come from here so that the Receive method will run forever!
                        IPAddress hostIPAddress1 = (Dns.Resolve("europe.battle.net")).AddressList[0];                        sock.Connect(new IPEndPoint(hostIPAddress1,80));
                        byte[] bytes = new byte[256];
                        k=sock.Receive(bytes);
                        Console.WriteLine("Received " + k + " bytes");
                        //---end socket part---
                  }
            }
      }

      class Class1
      {
            /// <summary>
            /// The main entry point for the application.
            /// </summary>
            [STAThread]
            static void Main(string[] args)
            {
                  //
                  // TODO: Add code to start application here
                  //
                  Start();
            }

            public static void Start()
            {
                  MyThread myTh1 = new MyThread();
                  Thread th1 = new Thread(new ThreadStart(myTh1.run));
                  th1.Name="TH1";
                  th1.Start();
                  
                  MyThread myTh2 = new MyThread();
                  Thread th2 = new Thread(new ThreadStart(myTh2.run));
                  th2.Name="TH2";
                  th2.Start();

                  Thread.Sleep(5000);

                  th1.Abort();
                  Thread.Sleep(500);
                  Console.WriteLine("th1 aborted -> status: " + th1.ThreadState.ToString());

                  Thread.Sleep(6000);

                  th2.Abort();
                  Thread.Sleep(500);
                  Console.WriteLine("th2 aborted -> status: " + th2.ThreadState.ToString());

            }
      }
}

This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.

Subscribe now for full access to Experts Exchange and get

Instant Access to this Solution

  • Plus...
  • 30 Day FREE access, no risk, no obligation
  • Collaborate with the world's top tech experts
  • Unlimited access to our exclusive solution database
  • Never be left without tech help again

Subscribe Now

Asked On
2003-09-02 at 01:41:04ID20726281
Tags

threadabortexception

Topic

.NET

Participating Experts
2
Points
250
Comments
7

Trusted by hundreds of thousands everyday for fast, accurate and reliable tech support.

  • "The time we save is the biggest benefit of Experts Exchange to Warner Bros. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange." Mike Kapnisakis, Warner Bros.
  • "Our team likes having a resource that is more secure than just using Google and most experts using this service really know their stuff. It's nice to look here first versus using Google." Dayna Sellner, Lockheed Martin
  • "Anytime that I've been stumped with a problem, 9 out of 10 times Experts Exchange has either the accepted solution or an open discussion of the potential solution to the problem." Kenny Red, eBay Inc.

See what Experts Exchange can do for you.

Got a question?

We've got the answer.

Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.

Screenshot of Experts Exchange Knowledgebase

Need individual assistance?

Our experts are ready to help.

If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.

Screenshot of Experts Exchange Knowledgebase

Want to learn from the best?

Read articles from industry experts.

Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.

Screenshot of an Article

Working on a long term project?

Store your work and research.

Save solutions to your questions, answers you’ve discovered through searching plus helpful articles in your personal knowledgebase for easy future access.

Screenshot of Experts Exchange Knowledgebase

Access the answers to your technology questions today.

Subscribe Now

30-day free trial. Register in 60 seconds.

What Makes Experts Exchange Unique?

Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.

Trusted by the world's most respected brands.

image of each brand's logo

Faithfully serving IT professionals since 1996.

Experts Exchange Logo

Try it out and discover for yourself.

Subscribe Now

30-day free trial. Register in 60 seconds.

Related Solutions

  1. Abort background process....
    I have application which takes a few menutes to load data into tree control, I need to give user a chance to abort this process. I would like to display modal dialog with some status data and button "Abort" which user should press to abort loading. The problem is ho...
  2. Aborting Threads in ASP.NET - how to actually Abort ?
    We've got a situation within one of our ASP.NET web pages (with underlying C# code). From one form we're setting up and starting a Thread - and storing it in the 'Session' object. So far our code is something like : st = new Something(parameter1, parameter2); Thread t = ne...
  3. using an unmanaged pointer .... aaaargh !!
    Hi! This is driving me nuts ... hopefully someone here can help me:) I have the foll. code: ------------------------ public ref class PSJVM { private: //JNIEnv is an unmanaged type JNIEnv* env; //JavaVM is an unmanaged type JavaVM* jvm; }; ---------------------- In t...
  4. Trouble killing a thread
    Howdy Experts! I'm using C# in the .NET framework 1.1 and using the CrystalReports.Engine.dll to generate a report. There are times when the Report will take an unexpectedly long time to run, like forever. In these cases I need a way to kill off the thread that is sucking ...

Free Tech Articles

  1. WARNING: 5 Reasons why you should NEVER fix a computer for free.
    It is in our nature to love the puzzle. We are obsessed. The lot of us. We love puzzles. We love the challenge. We thrive on finding the answer. We hate disarray. It bothers us deep in our soul. W...
  2. SCCM OSD Basic troubleshooting
    SCCM 2007 OSD is a fantastic way to deploy operating systems, however, like most things SCCM issues can sometimes be difficult to resolve due to the sheer volume of logs to sift through and the dispe...
  3. Migrate Small Business Server 2003 to Exchange 2010 and Windows 2008 R2
    This guide is intended to provide step by step instructions on how to migrate from Small Business Server 2003 to Windows 2008 R2 with Exchange 2010. For this migration to work you will need the fo...
  4. Create a Win7 Gadget
    This article shows you how to create a simple "Gadget" -- a sort of mini-application supported by Windows 7 and Vista. Gadgets can be dropped anywhere on the desktop to provide instant information, ...
  5. Outlook continually prompting for username and password
    There have been a lot of questions recently regarding Outlook prompting for a username and password whilst using Exchange 2007. There are a few reasons why this would happen and I will try to cover t...
  6. Backup Exchange 2010 Information Store using Windows Backup
    There seems to be quite a lot of confusion around the ability to backup Exchange 2010 using the built in Windows Backup feature. This stems from the omission of this feature prior to Exchange 2007 s...

Cloud Class Webinars

  1. Avoiding Bugs in Microsoft Access
    Alison Balter takes and in-depth look at avoiding bugs in Access. In this webinar you will learn about using the immediate window to debug your applications, invoking the debugger, using breakpoints to troubleshoot, stepping through code, setting the next statement to execute, ...
  2. Top 10 Best New Features in Visio 2010
    Scott Helmers gives live demonstrations of the top 10 new features in Visio 2010. This webinar will teach you how to create compelling diagrams by adding shapes to the page with a single click, linking the shapes in a diagram to data in Excel (or SQL Server, or SharePoint), ...
  3. IT Consultant Business Secrets Revealed
    Michael Munger, Experts Exchange tech pro and IT consultant, pulls back the curtain on his very successful businesses and answers question on every IT consultant and business owner should know about. He shares secrets on what he did to solve the 5 most common problems in IT, ...
  4. Disaster Recovery and Business Continuity
    Quest CTO, Mike Billon, gives an overview of the steps involved in building a dunamic disaster recovery plan. Through case studies and an examination of software/hardware tooles for monitoring and testing, you'll gain a better understandin of where you are, where you want ...
  5. Organize Your Visio Diagrams with Containers and Lists
    Scott Helmers uses cross functional flowcharts, wireframe diagrams, data graphic legends and seating charts to teach you: how to ustilize all three new structured diagram components in Visio 2010, the best practices for organizeing shapes in previous version of Visio, how to organize ...
  6. How to Us Objects, Properties, Events and Methods in Microsoft Access
    Alison Dalter gives an in-depbth look at objects, properties, events and methods in Microsoft Access. In this webinar you will learn about using the object browser, referring to objects, working with properties and methods, working with object variables, understanding the ...

Join the Community

Give a Little. Get a Lot.

Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.

Join the Community

Answers

 

by: _TAD_Posted on 2003-09-02 at 07:22:47ID: 9267450



I don't think you can abort a thread that is "sleeping".  I think you need to check the status first

if (th1.ThreadState == ThreadState.WaitSleepJoin)
{
     th1.Interrupt();
     th1.Abourt();
}

 

by: AzmodanPosted on 2003-09-02 at 07:33:27ID: 9267533

The thread is not sleeping. It's just hanged in the Socket.Receive method.
It's status is running...

 

by: _TAD_Posted on 2003-09-02 at 08:43:46ID: 9268061



Do you have these worker threads set up as background threads?


th1.IsBackground = true;
th1.Start();

 

by: _TAD_Posted on 2003-09-02 at 08:54:16ID: 9268153



One last thing....

Are you catching the ThreadAbortException ?  It doesn't look like it in this code (but this may not be ALL of your code).  This is a bit trivial, but good programming practice.  If you are going to kill a thread unexpectedly (for any reason), always have a catch routine to close down all connections and dispose of all other objects gracefully.

public void run()
{
              int i=0;
              int k=0;

try
{

              while(true)
              {
              ...
              ...
              ...
              }
}
catch(ThreadAbortException e)
{
    sock.Shutdown();
}
}

 

by: SeanChapmanPosted on 2003-09-02 at 16:43:55ID: 9270931

i prefer to use the non blocking sockets here, as they just throw an exception if there is nothing in the receive so i just go

while (AppRunning)
              try
      {
            socket.receive();
      }

      catch(SocketException ex)
      {
            
      }
}

now that thread wont hang in the receive and you can abort it.



 

by: AzmodanPosted on 2003-09-02 at 23:27:46ID: 9272289

SeanChapman -> the socket does not throw an exception if there is nothing to receive!! It just  hangs in the Receive method forever.
_TAD_ -> The ThreadAbortException is not thrown while the execution is hanged inside the receive method!!

if no other brilliant idea comes along, i'll accept the IsBackground answer, because that one at least prevents the program's zombification if a thread cannot be aborted.

 

by: SeanChapmanPosted on 2003-09-03 at 08:22:09ID: 9277821

Azmodan -> if the Socket.Blocking is set to false... it will not hang in the receive and will just throw a SocketException. so you can do this

socket.Blocking = false;
while (AppRunning)
            try
    {
         socket.receive();
    }

    catch(SocketException ex)
    {
         
    }
}

20120131-EE-VQP-002

3 Ways to Join

30-Day Free Trial

The Experts

98% positive feedback on 31,087 answers since March 2000. angeliii is a Microsoft Most Valuable Professional for his work with MS SQL Server & Develoment.

He has also proven his knowledge of Visual Basic Programming, PHP Scripting and Oracle Databases.

The Experts

97% positive feedback on 10,752 answers since July 2000. lrmoore has more than 18 years experience in the networking industry.

The six-time Mircosoft MVPs specialties include firewalls, virtual private networking, and network management.

Testimonials

"...and excellent source for support... Kind of like having your very own IT dept." Electriciansnet

Testimonials

"I was apprehensive at signing up at first. However... it has already made my life as an IT administrator much easier." JaCrews

Testimonials

"WOW! You guys have great, active, and knowledgeable people on here." moore50

Business Clients

Business Clients

In the Press

"If you’ve got a question... Experts Exchange can supply an answer.”

In the Press

"...an invaluable aid for both IT professionals and those who require tech support."

In the Press

"where IT professionals provide quick answers on just about any topic"

Business Account Plans

Loading Advertisement...