PC power button - Slightly off-topic
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From: Jim Stewart on 17 Mar 2010 15:17 I know that if you push the power button on a running PC, the machine does not power down until the OS has done its shutdown silly walk. Are there software hooks that allow an application to shutdown in an orderly fashion first?
From: D Yuniskis on 17 Mar 2010 15:54 Hi Jim, Jim Stewart wrote: > I know that if you push the power button on a > running PC, the machine does not power down > until the OS has done its shutdown silly walk. I think a "short" press causes that response. IIRC, the "hold for 4 seconds" behavior is done in hardware (to deal with the problem of a hung processor). I *vaguely* remember that from designing with COMBO chips in years past (I suspect most of those are no longer made as the floppy is a thing of the past) > Are there software hooks that allow an application > to shutdown in an orderly fashion first? Depends on the operating system. Of course, the application doesn't have to heed these warnings...
From: Mel on 17 Mar 2010 16:09 D Yuniskis wrote: > Hi Jim, > > Jim Stewart wrote: >> I know that if you push the power button on a >> running PC, the machine does not power down >> until the OS has done its shutdown silly walk. > > I think a "short" press causes that response. > IIRC, the "hold for 4 seconds" behavior is done > in hardware (to deal with the problem of a hung > processor). I *vaguely* remember that from designing > with COMBO chips in years past (I suspect most of those > are no longer made as the floppy is a thing of the past) > >> Are there software hooks that allow an application >> to shutdown in an orderly fashion first? > > Depends on the operating system. Of course, the application > doesn't have to heed these warnings... In Linux/Unix/Posix/... its the SIGTERM and SIGKILL signals. Mel.
From: Tim Wescott on 17 Mar 2010 16:39 D Yuniskis wrote: > Hi Jim, > > Jim Stewart wrote: >> I know that if you push the power button on a >> running PC, the machine does not power down >> until the OS has done its shutdown silly walk. > > I think a "short" press causes that response. > IIRC, the "hold for 4 seconds" behavior is done > in hardware (to deal with the problem of a hung > processor). I *vaguely* remember that from designing > with COMBO chips in years past (I suspect most of those > are no longer made as the floppy is a thing of the past) > >> Are there software hooks that allow an application >> to shutdown in an orderly fashion first? > > Depends on the operating system. Of course, the application > doesn't have to heed these warnings... I think it's 10 seconds. And yes, if you're not doing a hard power-down the OS will tap the applications on the shoulder, and point to the exit sign. -- Tim Wescott Control system and signal processing consulting www.wescottdesign.com
From: Tom on 17 Mar 2010 20:09
Tim Wescott wrote: > D Yuniskis wrote: >> Hi Jim, >> >> Jim Stewart wrote: >>> I know that if you push the power button on a >>> running PC, the machine does not power down >>> until the OS has done its shutdown silly walk. >> >> I think a "short" press causes that response. >> IIRC, the "hold for 4 seconds" behavior is done >> in hardware (to deal with the problem of a hung >> processor). I *vaguely* remember that from designing >> with COMBO chips in years past (I suspect most of those >> are no longer made as the floppy is a thing of the past) >> >>> Are there software hooks that allow an application >>> to shutdown in an orderly fashion first? >> >> Depends on the operating system. Of course, the application >> doesn't have to heed these warnings... > > I think it's 10 seconds. > > And yes, if you're not doing a hard power-down the OS will tap the > applications on the shoulder, and point to the exit sign. > Be aware that in Windows some applications may refuse and OS will not shut down. We had to look for a workaround for UPS to shutdown a PC with Citect Scada running on it. Tom |