The
XLockDisplay()
function locks out all other threads from using the specified display.
Other threads attempting to use the display will block until
the display is unlocked by this thread.
Nested calls to
XLockDisplay()
work correctly; the display will not actually be unlocked until
XUnlockDisplay()
has been called the same number of times as
XLockDisplay().
This function has no effect unless Xlib was successfully initialized
for threads using
XInitThreads().