Edit: In addition to the bounty, we're willing to pay $250 to have this bug fixed in the Firefox/Gecko codebase. Here is a simple test project (Visual Studio 2008 C#) that reproduces the problem.
Edit #2 we're willing to pay $600 to have this bug fixed. See above for sample project that reproduces the problem.
We have a Firefox (Gecko) ActiveX control on our C# Windows Form to display HTML.
When this Firefox ActiveX control is on our form, about 2-3% of our key presses don't make it through. Or rather, a different Windows message is sent:
We hold down the TAB key to tab through 3 regular WinForms text boxes. It will behave correctly 97% of the time. Spy++ tells us WM_KEYDOWN message is sent properly:
normal behavior http://judahhimango.com/images/normaltab.jpg
But randomly, maybe 2-3% of the time, the tab key (or other key) isn't processed right. Spy++ tells us WM_CHAR is being sent instead:
odd behavior http://judahhimango.com/images/screwytab.png
When the odd behavior occurs, either the key is not processed at all, or is processed incorrectly (such as inserting a '\t' character into a textbox that doesn't support tab characters.
This only occurs if the Firefox ActiveX control is on our form.
Our question is: does Firefox/Gecko engine install some kind of keyboard hook that might cause these side effects? Or better yet, how do we fix this problem?
The WM_CHAR message is generated by TranslateMessage call, so a good place to start looking would be the TranslateMessage calls in the Gecko source code.
In the first example code you provided the function is imported only by two libraries - mozctl.dll and xul.dll. Since you claim that the same error happens also with GeckoFX we can take mozctl.dll out of the equation. That leaves us with xul.dll, so given the Gecko source code I would suggest to look into widget\src\windows\nsToolkit.cpp. I am not sure if the code is run if the engine is embedded, but if it is then the library starts a whole new message pump in different thread, which is bound to break.
Unfortunately I can't run or compile the code on my machine (Windows 7 x64 w/o the Mozilla ActiveX control installed), so I can't verify any of this with a debugger. Hope it helps someone to track it down further.
The root problem is that when Mozilla is embedded in another application, it incorrectly pumps Windows messages when it dispatches internal events. Mozilla uses an event system to coordinate across threads or to schedule deferred processing on a thread (see nsIThread, nsIEventTarget). If you embed a web page with a lot of active XMLHTTPRequests, for example, Mozilla will use its event dispatching interface to dispatch events back to javascript and it will pump windows messages as a side effect. Once Mozilla events are fully dispatched, it goes back to the main event loop.
When Mozilla pumps windows messages, it doesn't include the extra processing done by the application's event loop - IsDialogMessage(), TranslateMessage(), PreTranslateMessage(), or any other pre-processing are skipped when Mozilla gets into this state. Symptoms therefore include tab key presses getting inserted as a character instead of being used for dialog navigation, keyboard hotkeys being sporadically ignored, or custom message pre-processing being sporadically skipped. For example, the Outlook 2007/2010 "Compose" screen sporadically loses keystrokes because it relies on custom message pre-processing to handle keyboard input.
See https://bugzilla.mozilla.org/show_bug.cgi?id=582790 for a patch that addresses the problem.
I have Snoop Free and PSM Anti-Keylogger.
One of them detected firefox trying to install a Keyboard Hook.
Mozilla/Firefox file xul.dll attempt at installing at keyboard hook.
DENIED.
I noticed that you have implemented all of the interoperability yourself. Can you try this with the GeckoFX project and see if you get the same error? I use this project at work and haven't encountered any issues yet.
Related
Just got into monogame today. Noticed that my software wasn't taking any keyboard inputs when I tried to bind a key to a fullscreen toggle. Weirdly enough, it takes inputs from my controller just fine, but just not the keyboard. Keyboard.GetState().GetPressedKeyCount() also always returns 0, so I've got no idea what's causing the problem.
I'm not usually one to attach full code files, but the program loop class is only 72 lines, so it's here if it helps: https://pastebin.com/xcWnDvqL
Platform: Windows 10 Build 19044
Monogame Version: 3.8.0.1641 (DesktopGL)
I tried to set up my project the same way as you did, but I am unable to reproduce the issue. It probably has something to do with your system. You can try the following and see if it works for you.
Now this may sound silly, but when you provide input, are you sure the window is active?
Your game can detect input from the gamepad even when the window is inactive, but the same is not true for keyboard input. I noticed this while testing your program. So ensure that the window is active (by clicking on your game window) before pressing a key and see if the game is still unable to detect input.
I hope that this is the problem in your case. If not try the other fixes as shown below.
Update the Monogame packages.
The latest version of monogame available is v3.8.1, so you can update your templates.
Proceed to install the latest nuget templates (as it was mentioned by Monogame that many bugs have been hotfixes in this version. You can do so by doing the following in a terminal.
dotnet new install MonoGame.Templates.CSharp::3.8.1.303
Then proceed to make a fresh desktopgl or mgwindowsdx project and see if the issue persists.
Check for driver issues.
Monogame uses xinput/DirectInput(a package in DirectX) to detect input from the input devices. Maybe the issue has something to do with it. You can search and run dxdiag from the start in windows. Ensure your drivers (including video drivers) are up to date.
In my App I have an annoying behavior. It is causing problems to my costumers.
The app has several points where I need to show a Dialog (Modal), then the users can fill some fields and then they can close the dialog. So the system follows its natural path.
In determined moments this works fine. The dialog is shown, user interacts with it, closes it , ....
But, in others moments (the same code) the dialog doesn't appear automatically. The user needs to execute some external action on device (like change its orientation, touch in the center of the screen, execute scroll gesture, etc). Some action that isn't intuitive at the moment.
This behavior makes the user think my app froze.
For me it is clear that the dialog was called, simply it wasn't drawed on the screen.
I tryed read about this problem.I did some researches in similar questions without success.
I guess the cause is related to EDT.
In short, How can I call a Dialog Modal without breaking EDT-rules.
And more specifically, How can I resolve this problem.
when I request a dialog to be displayed on the screen, I want it really appears in 100% of cases. Today works randomly.
Additional infomations:
My app uses Java 5 yet.
Do you recommends migration to Java 8?
======= Additional Informations (1) ===========
This problem is strongly dependent of device model.
In MotoG3 (Android 6) this problem is a exception. Rarely it occurs.
In my Galaxy Note 8 is the opposite. Always occurs.
In Lenovo Vibe5 (Android 6). Frequently occurs.
I added these informations. Maybe it help to compound problem picture.
Additional question:
Is it possible write a snippet that I can use as a template
to execute Dialog Modal call without break some rule of EDT?
Turn on the EDT violation detection tool in the simulator which should detect such issues. Inspect potentially problematic cases of Dialog calls and post them specifically if you don't know how to fix them.
Java 8 is unrelated although migrating a project is non-trivial.
TL;DR:
application is built with WPF, running on .Net 3.5
newest and older versions of the app work properly on many different machines
on one specific machine it malfunctions in a strange way:
either does not start, displays black screen instead of "welcome" screen; can't do anything on that black screen
or does start and works properly, until a TextBox is presented and until the user starts entering the text into it; then application immediatelly hangs
Background:
I have built a WPF application on .Net 3.5. I've checked the application on various machines with different OS, ranging from Windows XP up to Windows 7 - and it runs fine, no bugs, etc. It also works fine on my client's several target machines, XP and W7 included again.
However, on one machine, it suddenly ceased to work. My client sent me the machine so I can investigate. From the files on its drives, I can see there were older versions, and they were used by the client for a few months. I also see that the newest version is not installed yet on this machine. So, I tried running the old versions first, to see what's the problem.
What user sees:
oldest versions (say, v1, v2) of the application does not work at all. When they start up, the only thing the application displays is ... absolutely completely black window. There should be a "welcome" screen, composed of few images and labels and a button. The app is not frozen it is "responsive" (Win7 can communicate with it, the window is not dimmed).
last (but not newest, let's name it v3) application runs fine, everything is clickable, features work OK, except one. When user is asked to provide a password, the user is presented with single TextBox in a popup. When the user enters at least one character in that textbox, the application freezes. It freezes even before having rendered the masked '*' of the password. The freezing is total, the application stops responding (the window is dimmed and the OS wants to close it), CPU goes to 100% (actually 50%, two-core system) and the only way to stop is kill it via task manager.
then I installed and tried running the newest version (v4) - it behaves just like v3 above
I've also tried reinstalling all the versions, just to be ensure the .EXE/.DLL files are not damaged - no changes (v1/2 - black, v3/4 - freeze on text)
Technical bits, just FYI:
The app is very simple, one executable with no shared libraries and no shared configuration. There is just no way the newest version could interact with old versions. Seriously, I intentionally made the app in a way it can be "just copied" and several instances can be safely kept in separate folders.
All versions of the app (v4, v3, v2, v1) work properly on all other machines, with various versions of Windows
The problem can't be related to user files or configuration, I tried copying them from problematic machine to healthy ones, and the problem does not repeat
Related to password box: There are absolutely no event handlers in the code that could produce a deadlock or freezing. The password textbox has no text-changed handlers. My code reads the text only after an "OK" button is pressed. The app freezes immediatelly when user enters first character, the
user does not even get a chance to press "OK"
Related to startup: The app does almost nothing on startup. It merely displays some form of a splash/welcome screen. There is no logic there except for a nice UI and one button. The user has no chance of pressing that button. When the app starts, the screen is black and has no contents, not even the splash/welcome image.
Tracing and observations:
I've focused on the TextBox part, since it's more granular.
I've got the app to freeze again, and checked the threads with ProcessHacker.
Except for typical threads, one thread that was sitting and busy-spinning at:
wpfgfx_v0300.dll MilGlyphRun SetGeometryAtRenderTime
wpfgfx_v0300.dll MilGlyphRun SetGeometryAtRenderTime
...
wpfgfx_v0300.dll MilContent DetachFromHWND
That's certainly problem with the WPF layer itself. The DetachFromHWND tells me close to nothing, but MilGlyphRun is surely about the text rendering. It freezes while trying to render the text. I've checked the black-screens on older versions of the applications, but I couldn't catch it, since the apps were not frozen, just black.
So..
I've applied literally all pending updates (like, 150 of them, ~800 Mb, most of them were to the OS and .Net framework)
I've tried reinstalling all video drivers
No changes, still black screen, still freezing.
So, focusing back to the problem. It failed to render a text. Sounds obvious, since it deadlocked when user entered a character into a textbox, but it's damn not obvious! The user was presented with tons of different TextBoxes until he finally got to the PasswordBox. All TextBoxes worked OK, only this one fails. And why old verions of the app display black screen and the new version displays the "welcome" screen properly? How can be those issues related?
The connection is: Windows Presentation Foundation Font Cache service.
Sources:
http://support.microsoft.com/kb/937135
http://social.msdn.microsoft.com/Forums/vstudio/en-US/7cc032c1-5f4d-4518-adc6-f53afd051e6b/presentationhostexe-running-at-50-cpu?forum=wpf
WPF uses a Font-Cache service, running as a separate process, for, well, caching fonts. Whenever your WPF app needs to draw some text, it might ask the cache service for fonts. Once in a while the font cache might get corrupted and it then will/may randomly impact any WPF application.
Unfortunatelly, restarting the service is not enough. When this happens, you must delete all FontCache files that this service keeps on the disk. Before deleting them, you must stop the "Windows Presentation Foundation Font Cache service (or whatever it's called in your languge, for example Usługa buforowania czcionek platformy Windows Presentation Foundation in Polish..). Then, go to
Win7: %systemdrive%\Windows\ServiceProfiles\LocalService\AppData\Local\
Vista: %systemdrive%\Windows\ServiceProfiles\LocalService\AppData\Local\
WinXP: %systemdrive%\Documents and Settings\LocalService\Local Settings\Application Data
and remove all files looking like FontCache.dat. The source articles mentioned only one file (FontCache3.0.0.0.dat, but in my case there were around 8 files with similar naming convention).
After deleing them and restarting the service, all versions of my application were running properly again. No black screens, no freezing on textbox.
(see update below)
While running within the VisualStudio 2010 environment, I can easily tell if my Winform application causes an exception. I just have to go to Debug | Exceptions and make sure that both columns of checkboxes are checked. I then run the application and if any exceptions then I get dropped straight into the offending piece of code.
How do I determine exceptions during testing, when I give test build to a tester. I do not want the tester to run within Visual Studio, just as a regular user. I still want to know if there are exceptions and the pertinent details.
Obviosualy, I should be able to control the process, so that when the code gets released normal execution happens.
Yes, I know about and use try/catch blocks, but I am talking about a method similar to Visual Studio exception catcher and reporter, just possibly compiled into the product and used for deployment to beta testers.
Maybe Visual Studio has such a feature, in which case where and how to set up, or possibly a third party component.
[Update:
I added two sub-questions, which you can find at Unhandled Exception next line or exit.
The solution mentioned below sounds great and with a tweak probably works, just not at the moment.
Inside the Visual Studio both 2010 and now 2012 works great. The exception handler gets called, okay after VS breaks at the line and I say to continue. I decided to test outside the VS2012 IDE, good thing for that. The OS traps the bug, shows the standard an "An Unhandled Exception Occurred" dialog giving the details along with a continue and quit buttons. Selecting continue, just continues the application with no trapping into my uber exception handler. Selecting quite, whites-out the application and displays the standard close window dialog. The quit button also does not call my uber handler.
The purpose is so that my exception handler gets called. I do not need an uber exception handler if I am working inside the VS2012 IDE. The purpose of the handler is for end users and beta testers, namely anyone other than myself and who will not have my development station.
So unless I am missing something, the question is still open.
There are code samples in the other question, enough to copy and paste and create a test application in a couple minutes time.
]
Thanks in advance,
Sarah
I don't know of any automagical ways to reports error in Visual Studio but here is what I do.
Hook into the UnhandledException event for the application.
Use a logging framework like nLog or Log4Net to log the exception and other data you get from that event. Or just write to a text file.
Upload that data either from within your application or have the beta-tester send it to you.
Okay, the Google Uberlord took pitty upon me and I found this wonderful article solving the problem. Praise to the almighty Google.
Here is the link:
http://www.switchonthecode.com/tutorials/csharp-tutorial-dealing-with-unhandled-exceptions
Basically, JRadness had the right idea, just slightly in error. He should have used
Application.ThreadException +=
new System.Threading.ThreadExceptionEventHandler(Application_ThreadException);
rather than
AppDomain.CurrentDomain.UnhandledException +=
new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException);
The author on Switch on the Code talked of three methods, the first of which is what JRadness proposed and does not work for Windows forms.
The autor even solved my other question of Continue and Abort. The OS got bypassed.
Yeah!!
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