• Detecting Windows shutdown

    From Charlie Gibbs@21:1/5 to All on Sun Dec 12 05:56:13 2021
    I've written a program that does data collection. Normally it runs
    as long as Windows is up, although it can receive a command via a
    TCP/IP connection to tell it to do an orderly shutdown. The program
    also checks for a WM_QUERYENDSESSION message; in this case it displays
    a message box asking the user if it's OK to shut down. (I'm thinking
    of removing this message box and just doing an orderly shutdown

    This program is normally started and shut down by another program
    which manages various facilities in our system. The problem comes
    when this manager program is running as a service, which makes my
    program run as a service as well. It's a GUI program, so it can't
    display anything on the screen this way, but at least the Windows message-passing mechanism works properly for such things as timer
    ticks. The problem is that when Windows is shut down or restarted,
    I don't get a WM_QUERYENDSESSION message - when I log the message
    stream I see WM_TIMER messages, but then the program is silently
    killed without having the chance to flush buffers, close files,
    and clean up after itself. This can result in data loss.

    Is there any way to coax Windows to send me a WM_QUERYENDSESSION
    message when I'm running as a service? Or is there some other way
    I can determine when Windows is shutting down?

    The program is written in C and uses the standard Win32 API.


    /~\ Charlie Gibbs | Life is perverse.
    \ / <cgibbs@kltpzyxm.invalid> | It can be beautiful -
    X I'm really at ac.dekanfrus | but it won't.
    / \ if you read it the right way. | -- Lily Tomlin

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)