CrtTimerHdlr

Tcl_CreateTimerHandler(3)   Tcl Library Procedures   Tcl_CreateTimerHandler(3)



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NAME
       Tcl_CreateTimerHandler, Tcl_DeleteTimerHandler - call a procedure at a
       given time

SYNOPSIS
       #include <tcl.h>

       Tcl_TimerToken
       Tcl_CreateTimerHandler(milliseconds, proc, clientData)

       Tcl_DeleteTimerHandler(token)

ARGUMENTS
       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).
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DESCRIPTION
       Tcl_CreateTimerHandler arranges for proc to be invoked at a time
       milliseconds 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 isn't 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
       delayed.

       Proc should have arguments and return value that match the type
       Tcl_TimerProc:
              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.
       Typically, 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.
       because 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.


KEYWORDS
       callback, clock, handler, timer



Tcl                                   7.5            Tcl_CreateTimerHandler(3)