Question

I run a Visual C++ console test program inside the daily build. Every now and then the test would call some function that was changed by other developers improperly, descend into an infinite loop and hang thus blocking the build.

I need a watchdog solution as simple as possible. Here’s what I came up with. In the test program entry point I start a separate thread that loops continuosly and checks elapsed time. If some predefined period is exceeded it calls TerminateProcess(). Pseudocode:

DWORD WatchDog( LPVOID)
{
     DWORD start = GetTickCount();
     while( true ) {
        Sleep( ReasonablePeriod );
        if( GetTickCount() - start > MaxAllowed ) {
            TerminateProcess( GetCurrentProcess(), 0 );
        }
     }
     return 0;
}

Is this solution any worse than a watchdog implemented as a separate master program?

Answer 1

I think it’s preferable to implement the watchdog as a separate process. It’s easier to re-use it, it’s easier to detect if your app crashed and to get its return code.