XFlush(3X11)                  X11 SDE 5.4R3.00                  XFlush(3X11)


NAME
       XFlush, XSync, XEventsQueued, XPending - handle output buffer or
       event queue

SYNTAX
       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,



Licensed material--property of copyright holder(s)                         1

XFlush(3X11)                  X11 SDE 5.4R3.00                  XFlush(3X11)


       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





































Licensed material--property of copyright holder(s)                         2