Intercept signal / event when 'Stop Debugging' button is pressed in Visual Studio

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votes

Background: I am writing a QA automation platform for an API which outputs formatted results to a specified directory. In addition, I have developed a GUI application for analyzing these results. A user may run the second application trying to analyze test results while our automated build system is running the first application modifying / generating new test data. To avoid thrashing, I have each application acquire file locks when making modifications, and releasing them when they are done. Upon normal program termination, if the running application has acquired a lock on the data directory it is released.

Problem: I need to be able to release the aforementioned file locks when either tool exists prematurely (user pressing CTRL-C, user stopping the application in debugger, or due to buggy API / application logic being tested). To handle this, I have implemented a signal handler using sigaction which handles intercepting fatal signals (tested and working), and have implemented a ctrl-c handler via the Win32 function SetConsoleCtrlHandler. However, I cannot seem to find a way to intercept the event of a user pressing the Stop Debugging button in Visual Studio. I assume this event generates something like SIGKILL / SIGSTOP (which cannot be handled through sigaction) but I would also hope there is some std library or Win32 functionality to intercept this event and perform some cleanup. Do you guys know of a way to handle this event or even what exactly this button does to kill a running application?

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c++visual-studiosignals
The button will call TerminateProcess. There is no way for the target process to intercept that. However, a dying process will automatically release all locks (and all handles and all memory). What is not working for you? – avakar
As the file locks are acquired over nfs I cannot use flock. Also I cannot use fnctl as it is not available on windows. I use mkdir / rmdir as described in this post : stackoverflow.com/questions/6228915/… – Sir Digby Chicken Caesar
Perhaps it would be better to use F_SETLK/F_UNLCK fcntl locks on non Windows platforms and use some Win32 locking function on windows. Do you know of any Win32 file locking functions that work over nfs? – Sir Digby Chicken Caesar
Use msdn.microsoft.com/en-us/library/windows/desktop/… – avakar

1 Answers

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If you're using boost, you can use boost::interprocess::windows_shared_memory.

It is guaranteed to be released when the process ends.

Boost is just a neat wrapper around the windows API in this case. It wraps the Windows Named Shared Memory API.