CallDel

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     NAME
          Tcl_CallWhenDeleted, Tcl_DontCallWhenDeleted - Arrange for
          callback when interpreter is deleted

     SYNOPSIS
          #include <tcl.h>

          Tcl_CallWhenDeleted(interp, proc, clientData)

          Tcl_DontCallWhenDeleted(interp, proc, clientData)

     ARGUMENTS
          Tcl_Interp             *interp      (in)      Interpreter
                                                        with  which to
                                                        associated
                                                        callback.

          Tcl_InterpDeleteProc   *proc        (in)      Procedure   to
                                                        call      when
                                                        interp      is
                                                        deleted.

          ClientData             clientData   (in)      Arbitrary
                                                        one-word value
                                                        to   pass   to
                                                        proc.
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     DESCRIPTION
          Tcl_CallWhenDeleted  arranges  for  proc  to  be  called  by
          Tcl_DeleteInterp  if/when  interp  is deleted at some future
          time.  Proc will be invoked just before the  interpreter  is
          deleted, but the interpreter will still be valid at the time
          of the call.  Proc should have  arguments  and  result  that
          match the type Tcl_InterpDeleteProc:
               typedef int Tcl_InterpDeleteProc(
                    ClientData clientData,
                    Tcl_Interp *interp);
          The clientData and  interp  parameters  are  copies  of  the
          clientData     and     interp     arguments     given     to
          Tcl_CallWhenDeleted.  Typically,  clientData  points  to  an
          application-specific   data  structure  that  proc  uses  to
          perform cleanup when an interpreter is  about  to  go  away.
          Proc does not return a value.

          Tcl_DontCallWhenDeleted   cancels   a   previous   call   to
          Tcl_CallWhenDeleted  with  the  same arguments, so that proc
          won't be called after all when interp is deleted.  If  there
          is  no  deletion  callback  that  matches  interp, proc, and
          clientData then the call to Tcl_DontCallWhenDeleted  has  no
          effect.


     KEYWORDS
          callback, delete, interpreter