Vadump has usage information and a download from msdn and. Tool is intended to automate such analysis for managed application dumps. Tracking down managed memory leaks how to find a gc leak. Feb 05, 2012 recently, ive spent a couple of days seeking and fixing memory leaks in our silverlight application. Leaky applications will require more and more memory, until the program is shut down. Having spent considerable time searching for leaks in my silverlight app here are a few notes. You can use the sysinternals procdump tool to create a.
I was having a bit of trouble with a memory leak somewhere in my silverlight 4 application. The managed code was using native code via pinvoke. In our silverlight mvvm application were struggling for some time with the silverlight toolkit timepicker. To demonstrate some of the capabilities, ive written a trivial silverlight application with three buttons, one for each debugging scenario. This is done by observing the process memory behavior using task manager, performance counters or any other way of observing the memory usage of a process. Debugging a memory leak in silverlight 4 the grayzone. This tutorial will show you how to download, install, configure and test windbg in preparation for. Generally, you should not keep strong references of controls in your viewmodel. Scan thread 10 osthread 7ec scan thread 11 osthread e44 scan thread 12 osthread e04. For example, windbg is the tool i used to figure out why visual studio 2008 didnt allow.
I then discovered the very handy windbg tool that comes as part of the debugging tools for windows download. Dec 15, 2009 having spent considerable time searching for leaks in my silverlight app here are a few notes. Net applications despite what a lot of people believe, its easy to introduce memory and resources leaks in. First off, i do not know of any memory leak tools for silverlight. Feb 23, 2012 i used a trial version of redgate profiling software to look for the memory leak, but the memory leak is somewhere in the unmanaged code. Step 1 use process explorer to confirm the memory leak.
These steps will help you to go from a suspected memory leak to the specific object references. Memory leaks to watch out for in wpf and silverlight. Tracking down memory leaks in wpf and silverlight telerik. I used a trial version of redgate profiling software to look for the memory leak, but the memory leak is somewhere in the unmanaged code. For starters you will need to download and install windbg. Tracking down managed memory leaks how to find a gc leak by rico. This will show you the reference stack of an object allowing you to then see where your memory leak is coming from. Tech support scams are an industrywide issue where scammers trick you into paying for unnecessary technical support services. It might be tough sometimes, but its a good brainteasing practice and its a good way to learn how inner things work. If you are interested only in windbg, you can exclude everything else and only select debugging tools under common utilities. Download windbg for windows 7, windows 8, xp, server 2008. Every time i have to debug a memory leak in managed code,the first command i run is. Debugging finding a native heap leak with windbg debug.
Using driver verifier to find a kernelmode memory leak. I am experiencing a memory leak with the deexpress silverlight richedit control version 10. Improper use of the dispatchertimer will cause a memory leak. This technique reveals the pool tag associated with the memory leak. Once this has been selected click the button to download the 1 gb file. Mex debugging extension for windbg can help you simplify common debugger tasks, and provides powerful text filtering capabilities to the debugger. Recently, ive spent a couple of days seeking and fixing memory leaks in our silverlight application.
Once you have windbg up and running you can begin your first hunt. Run the silverlight application and bring it to a state where you think a memory problem exists. Ive solved so many memory leaks using their profiler. Once we have confirmed that there is a memory leak, its time to investigate the root problem of the memory leak.
Download debugging tools for windows windbg windows. Mar 20, 2014 this will show you the reference stack of an object allowing you to then see where your memory leak is coming from. Mar 12, 2009 using windbg, sos, and gcroot to diagnose a. Download mex debugging extension for windbg from official. Unlike other products with very complex user interfaces, umdh is a simple commandline interface program that only does two things, but does.
You should see a new window with the list of dlls used by the process. Process explorer creates 64 bit dumps on 64bit machines even for 32 bit applications. The first thing you need to do is download the windows debugging tools to the server. Sep 06, 2010 using windbg to find memory leaks in silverlight applications posted by sergey barskiy on 6 september 2010, 6. Windbg is the tool youll use most often when attaching to a process in production. Net memory leak thursday, march 12, 2009 in my last post, i explained how it was possible for hidden event handlers to introduce memory leaks and showed an easy way to prevent such leaks. Loaded the sos module for silverlight which is the managed debugging extension. Run windbg and attach to the internet explorer process running your silverlight application. The garbage collector, or gc for close friends, is not a magician who would completely relieve you from taking care of your memory and resources consumption. Install and configure windbg for bsod analysis tutorials. The customer felt there is a memory leak in the application. Silverlight application memory leaks detector in ui for. The windows debugger windbg can be used to debug kernelmode and usermode code, analyze crash dumps, and examine the cpu registers while the code executes.
Debugging finding a native heap leak with windbg 09 jan 2015 tweet. Net framework managed code and unmanaged code based applications. Having spent considerable time searching for leaks in my silverlight app. This person had basic debugging skills and was comfortable with sos. Windbg is part of the debugging tools for windows package. Tables of contents and indexes of windbg commands from all volumes. Detecting memory leaks in silverlight applications using. Aug 21, 2008 to troubleshoot silverlight applications with windbg and sos you would take a memory dump of the iexplore. Nov 10, 2010 i was having a bit of trouble with a memory leak somewhere in my silverlight 4 application. My issue may not be your issue, but it may get you thinking. Using the windbg tool we can see that after closing the view there are references on the view and of course also the viewmodel from the timepicker. Set the symbol path to a local directory on my system as well as the microsoft symbol servers when the tool needs to downloadresolve symbols.
In order to check memory leak you need to run the performance counter for hours or probably days together on production server to check if really there is a memory leak. One of the nice things about developing on a platform that uses a garbage collecting memory manager like silverlight and wpf is that the traditional concerns about memory leaks pretty much go away. To troubleshoot silverlight applications with windbg and sos you would take a memory dump of the iexplore. Windbg win dows d e b u g ger is a microsoft software tool that is needed to load and analyse the. Oct 07, 2015 once we have configured windbg for the symbol file path, start the process which is leaking memory, and attach windbg to it. Analysing memory dumps using windbg is rather complex in some cases.
I say most and not all because there are still a few ways to leak memory. A tool to compare two windbg dumpheap stats outputs. As observed in part 4, it can be difficult to trace the issue with just the help of perfmon tool. I have done a bit with win32 com before but not enough to know all of the ins and outs. Though there are tools available in the market that will help you in memory leak detection, most of these tools are not free. Windows debugging techniques debugging memory leaks. Set the symbol path to a local directory on my system as well as the microsoft symbol servers when the tool needs to download resolve symbols. Note that this does not download the whole sdk, its just an installer. There was nothing obvious in my code that was causing it, i was cleaning up and disposing of objects as i went.
Debugging silverlight applications with windbg and sos. Wpf and silverlight allow you to define your user interface and bind it to data with a minimum of code, meaning that you can also introduce memory leaks into your application without even realizing it. You can do so with either adplus as shown in my lab series or with debug diag, just remember that the process should be iexplore. Once we have configured windbg for the symbol file path, start the process which is leaking memory, and attach windbg to it. The latest version of windbg allows debugging of windows 10, windows 8. Finding memory leaks in wpfbased applications jawahars.
When i am analyzing a memory leak i first try to identify what is the operation. Windbg windows debugger is a microsoft software tool that is needed to load and analyse the. I found windbg as a freeware powerful tool to solve memory leak bugs. Right now im trying to analyzing the dump file of iexplorer. Using windbg to find memory leaks in silverlight applications. Memory leak refers to a gradual loss of memory space due to memory blocks not being released when they are no longer needed. Debugging silverlight apps this blog post shows how to investigate a potential memory leak within a silverlight application. The code below creates a new dispatchertimer within a user control, and to make it easier to see the leak, i have also added a byte array called mymemory to make the leak more obvious public byte mymemory new byte50 1024 1024. The native debugger has an extension for silverlight that helps you find memory leaks by showing you why your objects stick in memory. But, as i plow through some books and bad code examples i introduce all kinds of bugs. Jul 14, 2016 download directx enduser runtime web installer. The attach option in windbg is available under the file menu, or can be launched using the f6 shortcut.
Memory leak when using silverlight s timepickers in mvvm application. Net udf plugin i had to break away from my daily use of. Debugging silverlight applications with windbg the code. First step is to download tools for my windows 7 64 bit. Debugging finding a native heap leak with windbg debug things. When i am analyzing a memory leak i first try to identify what is the operation causing the leak.
Using it stops the view in which is used the timepicker to be garbage collected. Once you run the file, you can select which tools you would like to be downloaded. Using windbg to find memory leaks in silverlight applications posted by sergey barskiy on 6 september 2010, 6. Turns out my silverlight application had rogue children in the canvas. Configure the symbol file path to the microsoft symbol server srvd. Things get worst if the code is not written by you, or if the code base is quite huge. Memory leaks in silverlight applications may be found with windbg tool. Jun 22, 2010 download installers from the above links. B190807 silverlight richedit memory leak devexpress. Fyi the leak wasnt in the managed code, but in the native code.
Dec 19, 2008 but for some advanced debugging scenarios, like memory leak, deadlock, runaway processthread, kernel debugging, and advanced remotecrashui debugging etc, windbg or cdb, ntsd, kd is usually preferred, if not the only option. Admin access to your iis server so we can take memory dumps and copy. Detecting memory leaks in silverlight applications using windbg. In this exercise we shall discuss some of the fundamental steps in memory leak detection. Memory leaks are not an exception, especially with realworld application. I did some research, and decided to use windbg to help me pinpoint memory leaks. Step 4 use windbg to identify to identify whos holding on the type. Glavs blog debugging silverlight apps using windbg. I experienced what i thought where memory leak problems a few weeks ago. Debugging silverlight applications and detecting memory leaks is a daunting task that one must do when writing any nontrivial application using silverlight.
Hunting memory leaks in silverlight mikhail shilkov. At this moment, you have to find which one, among thousands of functions and many more allocated blocks, causes the application to leak and eventually to. How to detect and avoid memory and resources leaks in. In my case above, i had to open and close the suspect dialog multiple times. A tool to compare two windbg dumpheap stats outputs as a silverlight developer one of my favorite tools besides visual studio is windbg. Identifying memory leak with process explorer and windbg. If you do not know which kernelmode driver or component is responsible for the leak, you should use the poolmon technique first. There are numbers of blogs that folks wrote about memory leaks in microsoft. Windbg is a debugger that supports user mode debugging of a process, or kernel mode debugging of a computer. I have created a test harness application that dynamically creates the richedit control, adds it to a stackpanel, emoves it and garbage collects using windbg, it appears that there are 2 handlers that need to be unwired. Advanced windows rt memory dump analysis, arm edition. This blog,show coding practices that can cause memory leaks which are more unique to wpfbase apps share information about memory leaks in the.
Please feel free to download my free 500 question and answer ebook. An example of what this looks likegcroot 00000004c0106e78 note. Feb 15, 2009 the customer felt there is a memory leak in the application. Hunting down memory leaks in silverlight vishful thinking.
Debug silverlight 5 app process dump file with windbg. Following the steps below, you can confirm and debug memory leaks in silverlight and also in the. This installment goes over the commands used to show the memory used in a kernel mode. If you suspect that a part of your application may be leaking, you can use tools like windbg to check whether an object is still in memory and if it is, what references are keeping it there. Just have someone send you a memory dump and you can use that just as easily as if you were physically at the system. It would be so easy if someone could actually point where the precise location of the leak is and we all we have to do is fix it. But for some advanced debugging scenarios, like memory leak, deadlock, runaway processthread, kernel debugging, and advanced remotecrashui debugging etc. Memory leak when using silverlights timepickers in mvvm application. Windows debugging techniques debugging memory leaks crt apis background. Windbgtool is also able to parse some windbg commands output and display results not using plain text but via grid control which can filter and sort data.
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