XAddConnectionWatch(3X11)					  XLIB FUNCTIONS					 XAddConnectionWatch(3X11)

NAME

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

SYNTAX

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

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

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

       void XProcessInternalConnection(display, fd)
	     Display *display;
	     int fd;

       Status XInternalConnectionNumbers(display, fd_return, count_return)
	     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 private data in the location pointed to by watch_data; when the procedure is later called for this same connection
       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.  XAddConnectionWatch 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 connec-
       tions 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 procedure 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 inter-
       nal 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 speci-
       fied 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							    Release 6.6 					 XAddConnectionWatch(3X11)