I have written a simple vc++ background application. What am trying is like a watchdog service that could monitor if the application is running or not. If the application crashed then the service should start the application
For creating a setup through windows installer am using only the app.exe and app.dll.
Is that possible to create this watchdog - service in the exe itself ?
Unfortunately I have no idea of how to write such a program, does anyone have some example code that would demonstrate this technique please?
if so then how to make the default exe and watchdog exe as a single application to install ?
Your best route would be to create a separate service to act as the watchdog. Technically, it's possible to have the service and the "real application" in the same executable. You can differentiate between the two depending on how the exe has been started, but it will make maintenance quite difficult.
This article might be of interest.
Here - http://yadi.sk/d/EtzBRSMi3FqVH - is my implementation of WatchDog app, working in systray. Do not mind that it's written with Qt - the main functionality is with WinAPI.
This app is watching in processes list for several processes and restarts them if can't find. The second feature is that it monitors all windows in system for suspicious window title (for ex. "'My Great App' causes a system error and will be closed. Send message to developers ?") and, if find, restarts them too
P.S. I didn't i18n it, but I think there will no troubles )
Update: (according to #CodyGray comment)
Here's pastebin's links: WatchDog.cpp and WatchDog.h
Such a watchdog can be set up to, for example, write to a file every minute (or whatever). If the file hasn't been updated in two or more minutes then there is most likely a deadlock in the application and it has to be restarted.
Related
I have a C++ windows service running on system privileges and I need to make some changes in some of my DLLs that are loaded to several windows processes (explorer.exe, etc.).
The only time to do so is when these processes are down. I'm trying to make to impact to the UX minimal, so I don't wan't to force quit those or to popup any annoying message boxes and ask the user to do so.
I have tried to start this task on the startup of my service, the issue is several of these processes start before I finished it.
I'm trying to understand if there is a way to delay the start of processes on Windows startup, until I finish my task. Is there any event or anything familiar that I can set that will block those?
The other option is to do the needed task on shutdown. I did not find a way to do so yet, and all the related questions seem a bit old (how to delay shutdown and run a process in window service
), and regard to older version of windows.
This solution needs to be compatible with Windows versions greater than 7.
You can do this by using MoveFileEx and setting MOVEFILE_DELAY_UNTIL_REBOOT which will replace the file at the next reboot.
This should be well before any other processes have started, but without more details on your usecase its hard to tell if this'll work for you. Either way, searching for this flag should give you lots of information about this kind of issue.
According to the documentation, this has been supported since XP.
I'm facing an issue with TerminateProcess() function.
The application I'm currently writing a JobScheduler app that schedules and launches job at a specific time.
For this purpose, I'm using CreateProcess() to execute my JobLauncher.
The JobLauncher process then launches a console program (using createprocess ) which effectively executes the job executable, waits for its termination and monitors the duration, user and kernel times elapsed etc.
In order to kill the job from the JobScheduler I firstly started using TerminateProcess() but it does not allow me to close the executable itself properly. I mean i found no way to hook any termination event.
Until I find a better way than a brutal TerminateProcess(), I wrote an intermediate solution using the GenerateConsoleCtrlEvent() in the calling program.
In the job application that launches the target job executable, I installed a handler using SetConsoleCtrlHandler().
And in the handler, I can terminate the process of the job and notifies my thirdparties properly.
This is the better solution I found for now.
Is there a better way to programmaticaly and properly close a process ?
Do you this solution is completly absurd ?
I'm not a "system-level" specialist developer though...
Z.
This well know Windows console problem and you can find some solutions here.
We used on internal console utility which has name "Kamikaze". It worked as described here and for me it's a best solution cause there is no problem with porting between Windows versions and Windows architectures (x86, x64).
I am writing an application in Qt which gets executed by a launcher app. How can I detect whether the Qt application was launched by the user or the launcher. Is command line parameters the only way or is there a better way?
Both the Qt app and launcher are written by me.
Lots of ways. A command line parameter could be easily sniffed (by Process Explorer, e.g.), if that's a concern. But a named mutex or some other interprocess handle that can be inherited by the child app would be more difficult to spoof.
I was hoping somebody here had some insight into what could be causing this problem. I've implemented several COM extensions for Explorer that provide ShellIconOverlays and a ContextMenu, and the overlays work perfectly. The Context Menu works fine when I click on the desktop but when I right click in any explorer instance, I can see the interface being queried in the debugger and an instance of IShellExtInit being generated but the initialize function doesn't get called in the explorer instances, but it is called fine from the desktop and a ContextMenu item is queried immediately after.
Has anybody here seen anything like this before?
If you're debugging a shell extension, chances are that you've had occasions to terminate the running explorer.exe process and start a new one. When you started a new one, was it running with the same integrity level as the original?
Do your Explorer settings say to browse files in a new process? If so, is that process running with the same integrity level as the original?
Also, since you're running a debugger, chances are that you built a debug build. Does explorer.exe sometimes try to load the debug build of your DLL and sometimes try to load the release build of your DLL?
OK, I run into the exact same problem here, and it turns out that the issue has to do with
ThreadingModel = Apartment
Basically, what I think you are experiencing, is that the second thread of explorer.exe (desktop runs in STA thread) uses the default (legacy) ThreadingModel - and expects your COM to implement IMarshal to do IPC. Apartment ThreadingModel allows multiple instances of your IShellExt class to co-exist.
Caveat - If you are using ActiveQt to develop Context Menu Shell Extensions, there are few more tricks to use.
How can i programatically check if the windows shell (explorer) has loaded all startup programs & the user login process is over ?
There is a somewhat documented event you can wait for, but it is signaled when explorer has started loading. On XP this event is called "msgina: ShellReadyEvent" and "ShellDesktopSwitchEvent" on Vista. I linked to the sources of some alternative shells in a post related to this event.
Another alternative would be to listen for the Taskbar Creation Notification message. It can fire more than once so you would need to keep track of that.
On Vista+ there is one last alternative that might just work: Programs set to run at startup are part of a job object so they cannot run at high priority. If your program runs at startup you could maybe check for this, either by using IsProcessInJob or SetPriorityClass+GetPriorityClass in a loop. (SetPriorityClass will lie about its return value IIRC)