spicec-x11: Put locks around xlib calls which wait for a reply

Since libX11-1.3.4 the multi-threading handling code of libX11 has been
changed, see:
http://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=933aee1d5c53b0cc7d608011a29188b594c8d70b

This causes several issues. One of them is the display inside the
client not getting updated when there are no XEvents being generated,
this is caused by the following part of the referenced commit message:

Caveats:
- If one thread is waiting for events and another thread tries to read a reply,
  both will hang until an event arrives. Previously, if this happened it might
  work sometimes, but otherwise would trigger either an assertion failure or
  a permanent hang.

We were depending on the otherwise behavior and apparently were lucky.
This can be seen by starting F14 in runlevel 3 and then doing startx
and not touching the mouse / keyb afterwards. Once you move the mouse
(generate an event you see the UI contents being updated but not before.

Another thing both I and Alon (iirc) have seen are hangs where 2
threads are stuck in XSync waiting for a reply simultaneously. This might
be related to libxcb version, according to the libX11 commit a libxcb
newer then 1.6 was needed, and my system had 1.5 at the time I saw this
after updating to libxcb 1.7 I can no longer reproduce.

This patch tackles both problems (and is needed for the 1st one
indepently of the 2nd one possibly being fixed) by adding XLockDisplay
calls around all libX11 calls which wait for a reply or an event.

0 files changed, 0 insertions, 0 deletions