I've got reply from libx11 bug tracker. https://bugs.freedesktop.org/show_bug.cgi?id=89028#c1 Do `flush` from `Graphics.X11.Xlib.Event` after `resetScreenSaver` is the solution. `getScreenSaver` calls XFlush() internally. On Sun, Feb 8, 2015 at 10:10 PM, YCH wrote:

On Wed, Jan 21, 2015 at 3:22 PM, Dontdie YCH wrote:

...

Hello,

I'm looking for what is proper method to inhibit screensaver(DPMS) without xscreensaver, KDE, GNOME ... .

My video player 'bomi'(was cmplayer) try these, in order,

~~~ [App] Initialize screensaver functions. [App] Try to connect 'org.gnome.SessionManager'. [App] Failed to connect 'org.gnome.SessionManager'. Fallback to 'org.freedesktop.ScreenSaver'. [App] Failed to connect 'org.freedesktop.ScreenSaver'. Fallback to XResetScreenSaver(). [App] Disable screensaver with XResetScreenSaver(). ~~~

But it does not working. I didn't know how I directly deal with X11 lib. Fortunately, I found 'resetScreenSaver' from 'Graphics.X11.Xlib.Misc' that say interface to XResetScreenSaver().

resetScreenSaver.hs :

~~~ import Graphics.X11.Xlib import Graphics.X11.Xlib.Misc import Control.Concurrent import Control.Monad

main = do dpy <- openDisplay "" forever $ do putStrLn "reset" resetScreenSaver dpy threadDelay (5*1000000) ~~~

~~~ $ xset s 10 $ runhaskell resetScreenSaver.hs ~~~

Unfortunately, It does not working. `activateScreenSaver` and `forceScreenSaver` also does not working.

But `xset s reset` is working as intended and also there is `xdg-screensaver [ suspend | resume | reset ]` command from 'xdg-utils' package (Arch). It looks like abstraction layer for xset, xscreensaver, KDE, GNOME ... .

So I'm curious about whether this is bug of xorg or I misunderstand something. And what is right way to do this if I don't want any screensaver daemon? `xset s` or `xdg-screensaver`?

Thanks.

I've experiment couple of things and then find relation between `getScreenSaver` and `resetScreenSaver`. resetScreenSaver only works if I call getScreenSaver immediately before.

Any know about this?

Working as intended,

~~~ $ xset s 5; runhaskell withgetScreenSaver.hs $ cat withgetScreenSaver.hs import Graphics.X11.Xlib import Graphics.X11.Xlib.Misc import Control.Concurrent import Control.Monad

main = do dpy <- openDisplay "" forever $ do getScreenSaver dpy resetScreenSaver dpy threadDelay (3*1000000) ~~~

Does not working as intended,

~~~ $ xset s 5; runhaskell onlyresetScreenSaver.hs $ cat onlyresetScreenSaver.hs import Graphics.X11.Xlib import Graphics.X11.Xlib.Misc import Control.Concurrent import Control.Monad

main = do dpy <- openDisplay "" forever $ do resetScreenSaver dpy threadDelay (3*1000000) ~~~

If I call `getScreenSaver` outside loop, it also does not working.

~~~ import Graphics.X11.Xlib import Graphics.X11.Xlib.Misc import Control.Concurrent import Control.Monad

main = do dpy <- openDisplay "" getScreenSaver dpy forever $ do resetScreenSaver dpy threadDelay (3*1000000) ~~~

Thanks