I've "inherited" a legacy C#/C++ program that I have to debug. The current problem is that the .exe won't stop after I close the program, i.e. it still shows up in Task Manager.
This is a problem, because it won't let me restart the program, because only one instance can run. Often killing the process doesn't work; I'm forced to reboot.
I was under the impression that when the main program stopped, all the child threads were also supposed to stop, but I may be wrong.
Q: What would cause a .exe to not stop?
Child threads will not stop automatically unless they have been specifically set as background threads (i.e., with thread.IsBackground = true).
Edit: It is also possible that the main thread isn't terminating when the form is closed (i.e., there's other code that is set to run after close that isn't completing).
I find it useful to attach to the running process with the debugger and press the pause button. After that I would inspect the Threads window and see what the stack trace is doing for each of the executing threads. The threads window is hidden by default. Here is more information about how to show it and use it:
http://msdn.microsoft.com/en-us/library/w15yf86f.aspx
My guess would be that all threads aren't stopped. Usually you can end task the program and it will stop though. Maybe one thread has hung on to a system resource that's more difficult to release.
If you can get a debug build, run the program and after the program is "exited", hit the pause button in the debug window. At that point you can look through the threads and find out which one is hung. To help, you should name your threads when they get created (it's an extra parameter in the .Start function)
You may want to look into process explorer. It makes it easier to shut down the programs and it can view the threads of the program and potentially point you in the right direction of where to make the the program behave.
At the most frundamental level, there is an infinite loop somewhere.
Is the startup form the one that's being closed to exit the application? If it isn't you need to put Application.Exit() or Environment.Exit() in the form.closed event of the form that is closing last.
Related
I have installed a program ("CmisSync.exe") that runs as a small icon in the Windows system tray.
From C# I want to start it, and then exit it gracefully (as if a user had clicked "Exit" in the program's menu). Here is my attempt:
Process process = Process.Start(#"C:\Programs\CmisSync\CmisSync.exe");
// Wait for CmisSync's configuration/UI to start properly.
Thread.Sleep(5000);
// Close as if the user had clicked "Exit".
process.CloseMainWindow();
// Wait for CmisSync to finish what it is doing and exit normally.
// This might take a few minutes if a big sync is going on.
process.WaitForExit();
Unfortunately, CloseMainWindow does not make the program stop.
Maybe it is due to the program not actually have a main window? It only runs in the tray.
Close does not make the program stop either, by design.
Kill is not graceful, it does not let the program finish its current UI loop. Unlike the UNIX equivalent, the command does not seem to accept arguments indicating how brutal the kill should be.
The tray icon is implemented using System.Windows.Forms.Form
Yes, as you have discovered Process.CloseMainWindow only closes a program with a main window i.e you will most likely find the MainWindowHandle will be IntPtr.Zero
Process.CloseMainWindow Method ()
Closes a process that has a user interface by sending a close
message to its main window
Additionally, AFAIK WM_CLOSE or any other message wont help you either
However, you could create a message only window, or have your mainwindow set to invisible so you could message it in standard ways or call Process.CloseMainWindow.
However there are also many other IPC techniques you could use to the same affect, or even WCF. Anyway, since you're in control of the sync tray icon program, you can employ anything really (well except techniques that require a window evidently)
Interprocess Communications
Update
Since its open source, you can either edit as desired or have a look at the internals of it and you might find a way to gracefully close it.
Visual Studio Debug does not stop when i close the form that i write in C#. How can i stop debug process when i close form. I added Application.Exit() method in the form closing event but it didn't work.
Thank you.
Try this from here
If (System.Windows.Forms.Application.MessageLoop)
{
// Use this since we are a WinForms app
System.Windows.Forms.Application.Exit()
}
Else
{
// Use this since we are a console app
System.Environment.Exit(1)
}
EDIT:
If there are running infinite threads then do
Thread myThread = new Thread(...);
myThread.IsBackground = true; //set your running thread to background
myThread.Start(...);
And you can see how to? from here
Well this will be four years too late, however, I thought I'd post this for anyone else who runs into this issue (like I just did), sorry in advance if this is pretty basic, I'm fairly new to C# so this threw me for a bit.
I had the same issue as OP where, in my FormClosing event, neither Application.Exit() or Environment.Exit(0) would end the debugger.
The thing I found was looking at the reference count above my FormClosing event, it was showing '0 references'. I had just copied and pasted the closing event from another forum so there was no event handler to actually handle the event I had created/copied.
One easy way to resolve this (besides not copy and pasting code) was to create the event handler:
First go to the 'Form1.cs [Design]' tab
Navigate to the 'Properties' box
Click on 'Events'
Find 'FormClosing' and double click that
If you had the same issue you should now be able to see that there is at least 1 reference to the event. Now when you close the form it should also stop the debugger.
I landed on this question because VS was not stopping when a debugged application was shut down.
One way to see what might be causing the ide to hang is to click on pause and on the 'Debug Location' toolbar view any threads that are still running. For me I noticed that there was still a RabbitMq context that was not disposed of. So this was the clue i needed.
After I made the code change, VS now stops it debugging session once the application exits.
I know this is not a solution that you might be expecting but finding out why applications are not exiting properly or still keeping background processes alive is a very tricky subject. The active threads drop down is the best place to look imho.
Another possibility is, that your process runs in an exception which isn´t handled correctly. I used to show exception messages in self-build dialogs, but forgot to show the created window in one case. So the program ran into the exception, created the window but just didn´t show any sign of it... so the process kept running even when I closed the application.
I have an application that imports data from Excel. However, when I run the winforms app and I intrupt the application, using System.Windows.Forms.Application.Exit(); I can still see the "MyAppName".vshost32.exe running in task manager.
When I exit the application in debug mode, the form closes, but the VS IDE is not "stopped".
How do I ensure the application ends correctly.
Your call to Application.Exit() is working fine. The MyAppName.vshost32.exe executable is a host for debugging purposes. It runs whilst you have a project open in Visual Studio, regardless of if there is an active debugging session.
Update: Ok, I misunderstood. The above is true, but you're probably having problems with hung threads in the background. You need to terminate your threads to make it close properly. Asher's answer covers this. If you're just trying to do a super-hacky quick-and-dirty kill, you can use the following (though I take no responsibility for side effects, since it's extremely hacky):
System.Diagnostics.Process.GetCurrentProcess().Kill();
The process doesn't terminate because it still has foreground threads running.
If you create threads in your application you need to mark them as background threads or make sure they terminate when you want the application to exit.
Have you tried the more brutal Environment.Exit() function?
Application.Exit() just sends a message saying to shutdown; if the message never gets processed (for whatever reason), the application will stay running indefinitely.
From the MSDN documentation of Application.Exit():
The Exit method stops all running message loops on all threads and closes all windows of the application. This method does not necessarily force the application to exit. The Exit method is typically called from within a message loop, and forces Run to return.
I had a similar problem caused by a third party tool that did not allow me to set the threads as Background. Polynomial had the right idea, but then syntax is like this:
System.Diagnostics.Process.GetCurrentProcess().Kill();
i have a windows application C#4.0 with multithreadings problem is when i close the application ,the process stays on, no matter what i do so i have to do this:
environment.exit(1);
or the process wouldnt close,
problem is if i executed environment.exit(1) then application.restart() wouldn't work then.
any idea how to kill the process and then restart ?
Use the debugger. After you closed your main window, use Debug + Break All. Debug + Windows + Threads. Look at the call stack of the threads you see listed there to find the one that is preventing the program from terminating.
Make sure to make all your worker threads run in the background (set IsBackground to true before starting them). Background threads don't prevent the process from exiting.
threads that your application creates must be terminated before exiting the application otherwise CPU and/or memory will be consumed by the hanging threads
You can Exit application completely by typing this:
Application.Exit();
For Restarting Application Completely:
Application.Restart();
My winforms app isn't shutting down nicely when I log off/shutdown. I have a main form, whose Closing event is fired correctly, but there must be something else keeping my application around. If I check Application.OpenForms there's just my one main form.
The tricky bit, and where the problem probably lies, is that my application uses ShellWindows to hook into Internet Explorer, and occassionally opens up forms when IE events fire. It's after one or more of these forms has been opened and closed that my app stops closing on shutdown.
I think I'm cleaning up all form objects etc and calling FinalReleaseComObject() appropriately, but I guess there are references somewhere that are holding my process open. Is there any way to work out what it is that's stopping my app from closing gracefully?
An application will also stay open if there are threads running that have not been set to background. If you are creating any of your own threads, make sure that they are terminating appropriately.
If it is not critical that the thread finishes, set IsBackground to true. You can also call Abort on a thread to (somewhat)forcibly kill it.
The most likely cause is that you have a background thread hanging around that is not being closed when the main window of your application is closed. Depending on your settings and framework version background threads can keep an application alive when the main thread is terminated.
During shutdown windows asks every running app to terminate usually by sending a WM_QUIT to the main window on a process. WinForms will happily use this message to shutdown the main window but if any background threads are left the actual process could continue.
This is a really ugly way to do this, but if all you want to do is kill any thread that's hanging around, you can get all the threads running in your application with System.Diagnostics.Process.GetCurrentProcess.Threads, and then enumerate through them and call Thread.Join() or Thread.Abort() on them.
Just make sure to NOT call .Abort() on the main (UI) thread that you're working from (the one that receives the Closing event). So make sure to check that your current thread (System.Threading.Thread) is not the one you're aborting.