x11vnc is very laggy due to commit 8fbff6ce

Submitted by QDeKIFHFSzq4Uyvj7U

Assigned to Olivier Fourdan @olivier

Description

Date: Tue Mar 24 21:04:17 2015 +0100

Implement vsync using OpenGL

Bug: 11642

it references https://bugzilla.xfce.org/show_bug.cgi?id=11642

Coming from https://github.com/LibVNC/x11vnc/issues/102 where I found out that during a VNC Viewer connection(from laptop) to an x11vnc(on desktop), in the same vnc session(ie. without disconnecting), in the case when x11vnc was started while the monitor was off (required), if I disable/enable xfwm4 compositor(via Start->Window Manager Tweaks->Compositor->[] Enable display compositing) the x11vnc lag* is gone / comes back respectively!!

*The lag or delay refers to there being a 3 second delay in updating the screen(seen on the VNC Viewer side) the first time when pressing a key or moving a window, and then any subsequent updates taking 1 second each, until you stop giving any inputs for a few seconds(1-2sec?) then the same 3/1 delay can start again on any new input.

I'm currently using xfwm4 4.12 commit 37527851 to work around this issue(ie. no delay), because that commit is what git log 8fbff6ce0c097897a1f909dd02f72f4160f23d99~1 shows(ie. the previous commit before the bad commit? even though I can't get any form of git log $args to show them to me in consecutive order; so maybe I'm wrong about it being the previous? or I don't know)

I wasn't able to figure out how to revert the "bad" commit(as bisect called it) on top of latest git, but even latest git xfwm4 causes that same x11vnc delay.

This happens with modesetting driver as well as with intel driver, in xorg configs.

Version: GIT Master