X11R7.4 - man page for xinternalconnectionnumbers (x11r4 section 3)

XAddConnectionWatch(3)				    XLIB FUNCTIONS			       XAddConnectionWatch(3)

NAME
       XAddConnectionWatch, XRemoveConnectionWatch, XProcessInternalConnection, XInternalConnectionNumbers - handle
       Xlib internal connections

SYNTAX
       typedef void (*XConnectionWatchProc)(Display *display, XPointer client_data, int fd, Bool opening, XPointer
	      *watch_data);

       Status XAddConnectionWatch(Display *display, XWatchProc procedure, XPointer client_data);

       Status XRemoveConnectionWatch(Display *display, XWatchProc procedure, XPointer client_data);

       void XProcessInternalConnection(Display *display, int fd);

       Status XInternalConnectionNumbers(Display *display, int **fd_return, int *count_return);

ARGUMENTS
       client_data
		 Specifies the additional client data.

       count_return
		 Returns the number of file descriptors.

       display	 Specifies the connection to the X server.

       fd	 Specifies the file descriptor.

       fd_return Returns the file descriptors.

       procedure Specifies the procedure to be called.

DESCRIPTION
       The XAddConnectionWatch function registers a procedure to be called each time Xlib opens or closes an internal
       connection for the specified display.  The procedure is passed the display, the specified client_data, the
       file descriptor for the connection, a Boolean indicating whether the connection is being opened or closed, and
       a pointer to a location for private watch data.	If opening is True, the procedure can store a pointer to pri-
       vate data in the location pointed to by watch_data; when the procedure is later called for this same connec-
       tion and opening is False, the location pointed to by watch_data will hold this same private data pointer.

       This function can be called at any time after a display is opened.  If internal connections already exist, the
       registered procedure will immediately be called for each of them, before XAddConnectionWatch returns.  XAdd-
       ConnectionWatch returns a nonzero status if the procedure is successfully registered; otherwise, it returns
       zero.

       The registered procedure should not call any Xlib functions.  If the procedure directly or indirectly causes
       the state of internal connections or watch procedures to change, the result is not defined.  If Xlib has been
       initialized for threads, the procedure is called with the display locked and the result of a call by the pro-
       cedure to any Xlib function that locks the display is not defined unless the executing thread has externally
       locked the display using XLockDisplay.

       The XRemoveConnectionWatch function removes a previously registered connection watch procedure.	The
       client_data must match the client_data used when the procedure was initially registered.

       The XProcessInternalConnection function processes input available on an internal connection.  This function
       should be called for an internal connection only after an operating system facility (for example, select or
       poll) has indicated that input is available; otherwise, the effect is not defined.

       The XInternalConnectionNumbers function returns a list of the file descriptors for all internal connections
       currently open for the specified display.  When the allocated list is no longer needed, free it by using
       XFree.  This functions returns a nonzero status if the list is successfully allocated; otherwise, it returns
       zero.

SEE ALSO
       Xlib - C Language X Interface

X Version 11					     libX11 1.2.1			       XAddConnectionWatch(3)