hpux man page for xsync

XSync() 																   XSync()

Name
  XSync - flush the request buffer and wait for all events and errors to be processed by the server.

Synopsis
  XSync(display, discard)
	Display *display;
	int discard;

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

  discard   Specifies whether XSync() discards all events on the input queue.  This argument is either True or False.

Description
  XSync()  flushes  the request buffer, then waits until all events and errors resulting from previous calls have been received and processed
  by the X server.  Events are placed on the input queue.  The client's XError routine is called once for each error received.

  If discard is True, XSync() discards all events on the input queue (including those events that  were  on  the  queue  before  XSync()  was
  called).

  XSync()  is  sometimes used with window manipulation functions (by the window manager) to wait for all resulting exposure events.  Very few
  clients need to use this function.

See Also
  XFlush().

Xlib - Output Buffer															   XSync()