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,  XConnectionWatchProc  procedure,  XPointer
              client_data);

       void XRemoveConnectionWatch(Display  *display,  XConnectionWatchProc  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 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 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 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 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