hpux man page for xsynchronize

XSynchronize()															    XSynchronize()

Name
  XSynchronize - enable or disable synchronization for debugging.

Synopsis
  int (*XSynchronize(display, onoff))()
	Display *display;
	Bool onoff;

Arguments
  display   Specifies a connection to an X server; returned from XOpenDisplay().

  onoff     Specifies  whether	to enable or disable synchronization.  You can pass False (normal asynchronous mode) or True (enable synchro-
	    nization for debugging).

Returns
  The previous after function.

Description
  XSynchronize() turns on or off synchronous mode for debugging.  If onoff is True, it turns on synchronous behavior; False resets the	state
  to normal mode.

  When	events	are synchronized, they are reported as they occur instead of at some later time, but server performance is many times slower.
  This can be useful for debugging complex event handling routines.  Under UNIX, the same result can be achieved without hardcoding  by  set-
  ting the global variable _Xdebug to True from within a debugger.

  XSynchronize() returns the previous after function.

  For more information, see Volume One, Chapter 3, Basic Window Program.

See Also
  XQLength(),	XAllowEvents(),   XCheckIfEvent(),   XCheckMaskEvent(),  XCheckTypedEvent(),  XCheckTypedWindowEvent(),  XCheckWindowEvent(),
  XEventsQueued(), XGetInputFocus(), XGetMotionEvents(), XIfEvent(), XMaskEvent(), XNextEvent(),  XPeekEvent(),  XPeekIfEvent(),  XPending(),
  XPutBackEvent(), XSelectInput(), XSendEvent(), XSetInputFocus(), XWindowEvent().

Xlib - Input Handling														    XSynchronize()