I am kind of lost here, and I don't know what to do
I have a problem that I don't know what the source of it.
We have a large wpf application, that is built similar to prism (composite application)
Actually we are using lots of prism library.
I wrote a module to replace an existing module.
And the application now is loading my module, instead of the old module.
I start to notice, with the new module, that sometimes the application freeze for 20-30 seconds without any response, and then it work smoothly after that.
The freeze is not consistent, and there is no pattern or a specific reason that cause it.
I am suspecting that could be my module that is causing that freeze.
But at the same time, many other developers introduced new code to the application.
My question is there a way to trace that freeze?
Is there a way to compare the old module and the new module that I wrote?
I can run the application with my module, and trace the application, and then I can change the config file to load the old module.
Is there a way to compare between the two?
Should I do profiling?
and if profiling will help, then what should I look for?
any other tool could help?
Thanks a lot for any reply
It sounds like you are doing a long running operation on your UI thread. Are you making any database / webservice calls from the main thread? I think one of the easiest things to do is run it in the debugger, and when it freezes, hit the "pause" button. Visual Studio will pause execution at the current location, and you can examine what is taking so long.
If the problem isn't immediately obvious there, I would definitely start profiling the application to track this down.
Related
This scenario has come up before and I'm wondering if there is any way I can determine where the actively running form is executing within code? The problem is when I inherit a very large application which I'm not totally familiar with yet and I have it running through VS.NET 2010. I might have a particular screen up and go "geeze it would be nice if I could start debugging when I do 'x'".
If this was a simple form with some buttons I wouldn't even bother asking here; I'm not that novice. But the time consuming task is when I look at a tabbed screen in a large multi-project solution with drag and drop capabilities, right click options, etc. and have to spend 5-10 minutes tracking down where to place a breakpoint to debug.
What I'm wondering is if there is a way to have the WinForms app running via IDE and do 'something' that tells VS.NET on the next action break into the code (obviously without a breakpoint because I don't know where to place one yet). This would save me a ton of time trying to track down which event is occurring in a not so simple form or series of forms.
I hope this makes sense...
Thanks!
Yes, that's somewhat possible. When you use Debug + Break All then the 99.9% odds are that you don't break into code that's part of the project. A Winforms app is normally idle, pumping the message loop and waiting for Windows to tell it that something happened. You'll break at the Application.Run() statement.
The trick to then use Debug + Step Over. The program resumes running like normal. Then give a UI command (do 'x' in your question) and the debugger will break at the first statement of real code, typically at the start of the event handler for that command. It isn't exactly guaranteed that that code would be relevant, you might break at a MouseMove event handler for example. So YMMV.
I'm investigating strange WPF multi threaded application hang that happen randomly on production machines more easily than development ones.
I have added Application.Dispatcher.UnhandledException and CurrentDomain.UnhandledException event handlers to log the every and each exception in order to keep the application from crashing as it is a system shell.
I suspect the reason of the hang is that I'm handling those events and not allowing the application to crash, what make me say this is that when i monitored the application activity when it hanged using windows task manager i noticed CPU load probably caused by background tasks in the application and those background tasks are writing to logs as expected.
The logger class writes the logs to the disk asynchronously using BeginInvoke.
The big problem is every time the application hangs in production machine i find nothing in log files.
Now i have two questions:
What is the fire order of those events: "Application.Dispatcher.UnhandledException and CurrentDomain.UnhandledException".
2.Is there anyway i can manage to be able to know were my code is failing
Note: I use a lot of Thread.Sleep in background tasks as i manage the threads my self and i think i went wrong with this approach and I'm considering rewriting all of my background tasks from scratch.
Any help will be much appreciated.
Order of this event is:
Application.DispatcherUnhandledException
CurrentDomain.UnhandledException
If you want get information from exception where your code is failing, check property StackTrace. You can also attach to your project pdb files and in this case you will get StackTrace with line numbers.
The app is using my library which works using threads to do some operation; also it uses SIP VOIP library (obviously it is using threads). GUI is bound to interfaces of both libraries.
I noticed a weird behavior of my app. Usually it works just fine but sometimes after some time (3-5 minutes) it suddenly closes.
It is too irregular to debug it or diagnose.
Anyone had that kind of problem? Any idea what could be the reason for that?
I would recommend you add an application level error handler so that you can log any errors that are occuring that you might be missing. It is as simple as
Application.Current.DispatcherUnhandledException += HandleApplicationException;
Here is an MSDN article that describes it:
http://msdn.microsoft.com/en-us/library/system.windows.application.dispatcherunhandledexception.aspx
I have a WPF app that uses a non-WPF vendor library. My app does not receive any events that the library fires. I've been told that this is because I need a message pump.
In another (very similar) question, the accepted answer suggested using System.Windows.Threading.Dispatcher.Run().
When I add in that call, however, my window won't pop up-- the app is effectively backgrounded and I have to shut it down with Task Manager.
I'm really stumped here, and I'm not even sure how to investigate it. Any help would be greatly appreciated.
You already have one if you use WPF, there's no other way that it can get any Windows notifications. Every WPF app starts life with a call to Application.Run() on the main thread. It is usually well hidden, auto-generated in the bin\debug\app.g.cs source code file. Application.Run() in turn calls Dispatcher.Run()
Your vendor is correct, without a message loop many COM components go catatonic. But since you have one you need to look for the problem elsewhere. Don't use the component on threads.
I have a process (say, for example, MyProcessA), hooked an exe and injected my dll (MyDll.dll) into the process space of MyProcessA, so even if it's gonna create n number of child processes it will be process hooked as well. I have no problem in hooking and injecting the dll into the process. I have hooked all file and process dependant functions, but somehow I am not able to achieve complete hook of any setup (any application setup). I suspect if am missing any process related APIs or it might be some UAC problem, currently I am using CreateProcess(A&W), NtCreateProcess, ShellExecute(A&W). What could be the problem?
I suspect that the answer is related to the "Windows Installer Service". I'm guessing that your hooks wouldn't catch any interactions with a service, which even if launched as a result of FireFox's setup is going to be created by a different System process. I haven't had much experience with Windows Installer, but the documentation here should have more details than you could possibly wish for, given the time to find it.
UAC might also cause you issues, but you should be able to rule that out by launching the hooking code with administrative privileges to start with.
Is this research for uni? Either way good luck, it sounds like an interesting problem.