change to system clock blanks windows - Xwindows

This is a discussion on change to system clock blanks windows - Xwindows ; I've seen this behavior consistently over the years but the question is "why" and "how do I keep it from happening?" When I modify the system clock while running X the screen blanks momentarily. However, if I execute a date/time ...

+ Reply to Thread
Results 1 to 7 of 7

Thread: change to system clock blanks windows

  1. change to system clock blanks windows


    I've seen this behavior consistently over the years but the question is
    "why" and "how do I keep it from happening?"

    When I modify the system clock while running X the screen blanks
    momentarily. However, if I execute a date/time change using the date
    command from within an xterm I don't get any screen blanking.

    I need to have an X app modify the system time using the settimeofday()
    function and NOT blank the screen while the change is occurring.

    Anything I can do in the X11 API to keep this from happening?

  2. Re: change to system clock blanks windows

    Just Me writes:

    > I've seen this behavior consistently over the years but the question is
    > "why" and "how do I keep it from happening?"
    >
    > When I modify the system clock while running X the screen blanks
    > momentarily. However, if I execute a date/time change using the date
    > command from within an xterm I don't get any screen blanking.
    >
    > I need to have an X app modify the system time using the settimeofday()
    > function and NOT blank the screen while the change is occurring.
    >
    > Anything I can do in the X11 API to keep this from happening?


    It's probably the screensaver activating because the system suddenly
    indicates that more time has passed. I've seen that happen on
    occasion.

    --
    Måns Rullgård
    mans@mansr.com

  3. Re: change to system clock blanks windows

    On Fri, 29 Feb 2008 02:18:25 +0000, Måns Rullgård wrote:

    > Just Me writes:
    >
    >> I've seen this behavior consistently over the years but the question is
    >> "why" and "how do I keep it from happening?"
    >>
    >> When I modify the system clock while running X the screen blanks
    >> momentarily. However, if I execute a date/time change using the date
    >> command from within an xterm I don't get any screen blanking.
    >>
    >> I need to have an X app modify the system time using the settimeofday()
    >> function and NOT blank the screen while the change is occurring.
    >>
    >> Anything I can do in the X11 API to keep this from happening?

    >
    > It's probably the screensaver activating because the system suddenly
    > indicates that more time has passed. I've seen that happen on occasion.



    good call. I thought of that and disabled the screensaver to test.
    Unfortunately the phenomenon still occurs. I'm disabling the screensaver
    with

    xset s 0 0

    any other way I should be attempting to disable it?


  4. Re: change to system clock blanks windows

    Just Me writes:

    > On Fri, 29 Feb 2008 02:18:25 +0000, Måns Rullgård wrote:
    >
    >> Just Me writes:
    >>
    >>> I've seen this behavior consistently over the years but the question is
    >>> "why" and "how do I keep it from happening?"
    >>>
    >>> When I modify the system clock while running X the screen blanks
    >>> momentarily. However, if I execute a date/time change using the date
    >>> command from within an xterm I don't get any screen blanking.
    >>>
    >>> I need to have an X app modify the system time using the settimeofday()
    >>> function and NOT blank the screen while the change is occurring.
    >>>
    >>> Anything I can do in the X11 API to keep this from happening?

    >>
    >> It's probably the screensaver activating because the system suddenly
    >> indicates that more time has passed. I've seen that happen on occasion.

    >
    > good call. I thought of that and disabled the screensaver to test.
    > Unfortunately the phenomenon still occurs. I'm disabling the screensaver
    > with
    >
    > xset s 0 0
    >
    > any other way I should be attempting to disable it?


    This should disable any screen blanking:

    xset s off dpms 0 0 0

    --
    Måns Rullgård
    mans@mansr.com

  5. Re: change to system clock blanks windows

    On Fri, 29 Feb 2008 02:28:45 +0000, Måns Rullgård wrote:

    >> good call. I thought of that and disabled the screensaver to test.
    >> Unfortunately the phenomenon still occurs. I'm disabling the
    >> screensaver with
    >>
    >> xset s 0 0
    >>
    >> any other way I should be attempting to disable it?

    >
    > This should disable any screen blanking:
    >
    > xset s off dpms 0 0 0


    thanks. that was the solution. I didn't have a reference that
    adequately explained the format of xset with regard to screen blanking
    and dpms.




  6. Re: change to system clock blanks windows

    In article <47c76a2f$0$31116$ec3e2dad@unlimited.usenetmonster. com>,
    Just Me writes:
    >
    >
    > I need to have an X app modify the system time using the settimeofday()
    > function


    Why? If your ntpd is working properly it should keep the clock in sync
    without settimeofday(). And slewing the clock by a few ppm as ntpd does
    has no side effects on the screensaver.

  7. Re: change to system clock blanks windows

    On Sat, 01 Mar 2008 16:46:48 +0000, Dick Wesseling wrote:

    > In article <47c76a2f$0$31116$ec3e2dad@unlimited.usenetmonster. com>,
    > Just Me writes:
    >>
    >>
    >> I need to have an X app modify the system time using the settimeofday()
    >> function

    >
    > Why? If your ntpd is working properly it should keep the clock in sync
    > without settimeofday(). And slewing the clock by a few ppm as ntpd does
    > has no side effects on the screensaver.


    because not all systems, especially embedded systems, have access to an
    external clock source for ntpd.


+ Reply to Thread