My process sometimes throws exception like dllnotfound after start. i have a monitor service responsible for maintaining the consistent state of the process.
how can i keep track of state of my process using windows service.
is there an open source implementation of windows service that maintains/track the state of process in windows.
Edit: So the actual problem wasn't that the process was dying, but that the process was stuck in an exception handler dialog waiting for the user to hit debug or cancel. The solution to the problem was to disable the .net JIT debug dialog, instructions here http://weblogs.asp.net/fmarguerie/archive/2004/08/27/how-to-turn-off-disable-the-net-jit-debugging-dialog.aspx
My original proposed solution is below
Not a window service, but this is a pretty easy .NET program to write.
use System.Diagnostics.Process to get a Process object for the process you want to check. You can use GetProcessByName if you want to open an existing process. If you create the process from C#, then you will already have the process object.
Then you just can WaitForExit either with or without a timeout on the Process object. or test the HasExited property, or register an Exited callback. Once the process has exited, you can check the ExitCode property to find out whether the process returned an error value.
That's not possible, exceptions are local to a thread first, local to a process secondary if it is unhandled. An unhandled exception will terminate the process. The only shrapnel you could pick up from such a dead process is the process exit code. Which should be set to 0xe0434f4e, the exception code for an unmanaged exception. No other relevant info is available, unless there's an unhandled exception handler in the process that logs state. That state is very unreliable, the process suffered a major heart attack.
Keeping multiple processes in synch and running properly when they may die from exceptions is extraordinarily difficult. Only death can be detect reliably, avoid doing more.
One thing you could do is to monitor the CPU usage of the process. I am assuming your process goes away when the exception is thrown. Therefore, the CPU usage of the process should be 0 since it is no longer available. Therefore, if the CPU usage stays at zero for a certain period of time, you can safely assume that the process has raised the exception. This method is not fool proof since you are basing your decision on CPU usage and a legitimate process may have a zero CPU usage for a given period of time. You can incorporate this check inside your monitoring service or you could write a simple VB script to check process CPU usage externally.
In the case of DllNotFoundException and other things that happen at startup, you can have the application indicate when it's finished starting up. Have it write a timestamp to a file, for instance. Your monitor can compare the time the application started with the time in the file.
Have your process write events and exceptions to the system's application log and have your monitor check for entries periodically to find events relating to your process, and you can check the system events for service start and stop events.
If the process itself is a windows service, you can check its status using the `System.ServiceProcess.ServiceController'.