Index for Section 3X11

Alphabetical listing for X

Bottom of page

XFlush(3X11)
X11R6
NAME
  XFlush, XSync, XEventsQueued, XPending - handle output buffer or event
  queue

SYNOPSIS
  XFlush(display)
	  Display *display;

  XSync(display, discard)
	  Display *display;
	  Bool discard;

  int XEventsQueued(display, mode)
	  Display *display;
	  int mode;

  int XPending(display)
	  Display *display;

ARGUMENTS
  discard
      Specifies a Boolean value that indicates whether XSync discards all
      events on the event queue.

  display
      Specifies the connection to the X server.

  mode
      Specifies the mode. You can pass QueuedAlready, QueuedAfterFlush, or
      QueuedAfterReading.

DESCRIPTION
  The XFlush function flushes the output buffer. Most client applications
  need not use this function because the output buffer is automatically
  flushed as needed by calls to XPending, XNextEvent, and XWindowEvent.
  Events generated by the server may be enqueued into the library's event
  queue.

  The XSync function flushes the output buffer and then waits until all
  requests have been received and processed by the X server.  Any errors
  generated must be handled by the error handler. For each protocol error
  received by Xlib, XSync calls the client application's error handling
  routine (see section 11.8.2). Any events generated by the server are
  enqueued into the library's event queue.

  Finally, if you passed False, XSync does not discard the events in the
  queue. If you passed True, XSync discards all events in the queue,
  including those events that were on the queue before XSync was called.
  Client applications seldom need to call XSync.

  If mode is QueuedAlready, XEventsQueued returns the number of events
  already in the event queue (and never performs a system call). If mode is
  QueuedAfterFlush, XEventsQueued returns the number of events already in the
  queue if the number is nonzero. If there are no events in the queue,
  XEventsQueued flushes the output buffer, attempts to read more events out
  of the application's connection, and returns the number read. If mode is
  QueuedAfterReading, XEventsQueued returns the number of events already in
  the queue if the number is nonzero. If there are no events in the queue,
  XEventsQueued attempts to read more events out of the application's
  connection without flushing the output buffer and returns the number read.

  XEventsQueued always returns immediately without I/O if there are events
  already in the queue.	 XEventsQueued with mode QueuedAfterFlush is
  identical in behavior to XPending.  XEventsQueued with mode QueuedAlready
  is identical to the XQLength function.

  The XPending function returns the number of events that have been received
  from the X server but have not been removed from the event queue.  XPending
  is identical to XEventsQueued with the mode QueuedAfterFlush specified.

SEE ALSO
  AllPlanes(3X11), XIfEvent(3X11), XNextEvent(3X11), XPutBackEvent(3X11)

  Xlib -- C Language X Interface

Index for Section 3X11

Alphabetical listing for X

Top of page