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Tcl_CreateTimerHandler(3)   Tcl	Library	Procedures   Tcl_CreateTimerHandler(3)


       Tcl_CreateTimerHandler,	Tcl_DeleteTimerHandler - call a	procedure at a
       given time

       #include	<tcl.h>

       Tcl_CreateTimerHandler(milliseconds, proc, clientData)


       int milliseconds	(in)			 How many milliseconds to wait
						 before	invoking proc.

       Tcl_TimerProc *proc (in)			 Procedure   to	 invoke	 after
						 milliseconds have elapsed.

       ClientData clientData (in)		 Arbitrary one-word  value  to
						 pass to proc.

       Tcl_TimerToken token (in)		 Token	for previously created
						 timer	handler	 (the	return
						 value from some previous call
						 to Tcl_CreateTimerHandler).

       Tcl_CreateTimerHandler arranges for proc	to be invoked at a  time  mil-
       liseconds  milliseconds	in  the	 future.  The callback to proc will be
       made by Tcl_DoOneEvent, so Tcl_CreateTimerHandler  is  only  useful  in
       programs	 that  dispatch	 events	 through Tcl_DoOneEvent	or through Tcl
       commands	such as	vwait.	The call to proc may not be made at the	 exact
       time  given  by	milliseconds:  it will be made at the next opportunity
       after that time.	 For example, if Tcl_DoOneEvent	is  not	 called	 until
       long  after  the	time has elapsed, or if	there are other	pending	events
       to process before the call to proc, then	the call to proc will  be  de-

       Proc  should  have  arguments  and  return  value  that	match the type
	      typedef void Tcl_TimerProc(ClientData clientData);
       The clientData parameter	to proc	is a copy of the  clientData  argument
       given  to  Tcl_CreateTimerHandler when the callback was created.	 Typi-
       cally, clientData points	to a data  structure  containing  application-
       specific	information about what to do in	proc.

       Tcl_DeleteTimerHandler  may  be	called	to delete a previously created
       timer handler.  It deletes the handler indicated	by token  so  that  no
       call  to	proc will be made;  if that handler no longer exists (e.g. be-
       cause the time period has already elapsed and  proc  has	 been  invoked
       then  Tcl_DeleteTimerHandler  does  nothing.   The  tokens  returned by
       Tcl_CreateTimerHandler never have a value of NULL, so if	NULL is	passed
       to Tcl_DeleteTimerHandler then the procedure does nothing.

       callback, clock,	handler, timer

Tcl				      7.5	     Tcl_CreateTimerHandler(3)


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