Channel 9 Microsoft http://mschnlnine.vo.llnwd.net/d1/Dev/App_Themes/C9/images/feedimage.png Channel 9 http://channel9.msdn.com/Niners/jeff_dailey/Posts Channel 9 keeps you up to date with the latest news and behind the scenes info from Microsoft that developers love to keep up with. From LINQ to SilverLight – Watch videos and hear about all the cool technologies coming and the people behind them. http://channel9.msdn.com/Niners/jeff_dailey/Posts en Tue, 21 May 2013 19:59:21 GMT Tue, 21 May 2013 19:59:21 GMT Rev9 2 1 25 Understanding handle leaks and how to use !htrace to find them

Hello, my name is Jeff Dailey, I’m an Escalation Engineer for the Global Escalation Services Platforms team.   I’d like to show you how to debug and find leaking handles within your application or other process.  We can do this with the !htrace command in windbg .  Windbg is the Microsoft Windows Debugger most of us use in GES/CPR  for debugging.   

 

Handles are a value we use in user mode, that when passed to a call that transitions to kernel, are used as an offset in your handle table to reference kernel mode objects.  Kernel mode objects are generally allocated from pool.   If you are having pool consumption problems and seeing errors like 2020 or 2019’s reported there is a good chance you may have a handle leak associated with them.  This is generally due to not doing a CloseHandle() on the handle when you have finished using it.

 

The following is the sample source for a handle leak that we will be debugging in our demo video.

 

// leakyhandles.cpp : Defines the entry point for the console application.

//

 

#include "stdafx.h"

#include <windows.h>

 

 

void fun1(void);

void fun2(void);

void fun3(void);

void fun4(void);

 

int main(int argc, char* argv[])

{

      while(1)

      {

            fun1();

            fun2();

            Sleep(100);

      }

      return 0;

}

 

void fun1(void)

{

      fun3();

}

 

void fun2(void)

{

      fun4();

 

}

void fun3(void)

{

      HANDLE hEvent;

 

      hEvent = CreateEvent(NULL,TRUE,TRUE,NULL);

      CloseHandle(hEvent);

}

void fun4(void)

{

    HANDLE hEvent2;

 

      hEvent2 = CreateEvent(NULL,TRUE,TRUE,NULL);

}

 

Thank you.

Jeff Dailey

Escalation Engineer (Platforms core team)

]]> http://channel9.msdn.com/Blogs/jeff_dailey/Understanding-handle-leaks-and-how-to-use-htrace-to-find-them Hello, my name is Jeff Dailey, I’m an Escalation Engineer for the Global Escalation Services Platforms team.&nbsp;&nbsp; I’d like to show you how to debug and find leaking handles within your application or other process.&nbsp; We can do this with the !htrace command in windbg .&nbsp; Windbg is the Microsoft Windows Debugger most of us use in GES/CPR&nbsp; for debugging.&nbsp;&nbsp;&nbsp; &nbsp; Handles are a value we use in user mode, that when passed to a call that transitions to kernel, are used as an offset in your handle table to reference kernel mode objects.&nbsp; Kernel mode objects are generally allocated from pool.&nbsp;&nbsp; If you are having pool consumption problems and seeing errors like 2020 or 2019’s reported there is a good chance you may have a handle leak associated with them.&nbsp; This is generally due to not doing a CloseHandle() on the handle when you have finished using it. &nbsp; The following is the sample source for a handle leak that we will be debugging in our demo video. &nbsp; // leakyhandles.cpp : Defines the entry point for the console application. // &nbsp; #include &quot;stdafx.h&quot; #include &lt;windows.h&gt; &nbsp; &nbsp; void fun1(void); void fun2(void); void fun3(void); void fun4(void); &nbsp; int main(int argc, char* argv[]) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; while(1) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; fun1(); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; fun2(); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Sleep(100); &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; } &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; return 0; } &nbsp; void fun1(void) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; fun3(); } &nbsp; void fun2(void) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; fun4(); &nbsp; } void fun3(void) { &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; HANDLE hEvent; &nbsp; &nbsp;&nbsp;&nbsp;&nb 536 http://channel9.msdn.com/Blogs/jeff_dailey/Understanding-handle-leaks-and-how-to-use-htrace-to-find-them Fri, 14 Sep 2007 18:35:01 GMT http://channel9.msdn.com/Blogs/jeff_dailey/Understanding-handle-leaks-and-how-to-use-htrace-to-find-them jeff_dailey jeff_dailey 8 http://channel9.msdn.com/Blogs/jeff_dailey/Understanding-handle-leaks-and-how-to-use-htrace-to-find-them/RSS ntdebugging blog talk about on desktop heap Hi, This is Jeff Dailey, I’m an Escalation Engineer (EE) from the Microsoft GES (Global Escalation Services) Platforms team.   This is the first in an ongoing series of videos based on our advanced debugging and troubleshooting blog hosted on http://blogs.msdn.com/ntdebugging. In this video Matthew Justice (GES EE) , David Butler (GES EE) and I will discuss desktop heap architecture , and the types of things that go wrong and how to address them.   Matthew is the author of “Desktop Heap Overview” on http://blogs.msdn.com/ntdebugging/archive/2007/01/04/desktop-heap-overview.aspx 


The video is about 15 minutes long , as a side note this was recorded on our new Microsoft roundtable camera.  http://www.microsoft.com/uc/products/roundtable.mspx

 

Thank you and enjoy

 

Jeff Dailey

Escalation Engineer (Platforms core team)

]]> http://channel9.msdn.com/Blogs/jeff_dailey/ntdebugging-blog-talk-about-on-desktop-heap Hi, This is Jeff Dailey, I’m an Escalation Engineer (EE) from the Microsoft GES (Global Escalation Services) Platforms team.&nbsp;&nbsp; This is the first in an ongoing series of videos based on our advanced debugging and troubleshooting blog hosted on http://blogs.msdn.com/ntdebugging. In this video Matthew Justice (GES EE) , David Butler (GES EE) and I will discuss desktop heap architecture , and the types of things that go wrong and how to address them.&nbsp;&nbsp; Matthew is the author of “Desktop Heap Overview” on http://blogs.msdn.com/ntdebugging/archive/2007/01/04/desktop-heap-overview.aspx&nbsp; The video is about 15 minutes long , as a side note this was recorded on our new Microsoft roundtable camera. &nbsp;http://www.microsoft.com/uc/products/roundtable.mspx &nbsp; Thank you and enjoy &nbsp; Jeff Dailey Escalation Engineer (Platforms core team) http://channel9.msdn.com/Blogs/jeff_dailey/ntdebugging-blog-talk-about-on-desktop-heap Thu, 13 Sep 2007 11:37:22 GMT http://channel9.msdn.com/Blogs/jeff_dailey/ntdebugging-blog-talk-about-on-desktop-heap jeff_dailey jeff_dailey 2 http://channel9.msdn.com/Blogs/jeff_dailey/ntdebugging-blog-talk-about-on-desktop-heap/RSS