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.
________________________________________________________________________________________________________________

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 void 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  will not 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.

       Note that if the  callback  is  being  used  to  delete  a  resource  that  must  be  released  on  exit,
       Tcl_CreateExitHandler  should  be  used  to  ensure  that  a callback is received even if the application
       terminates without deleting the interpreter.

SEE ALSO

       Tcl_CreateExitHandler(3tcl), Tcl_CreateThreadExitHandler(3tcl)

KEYWORDS

       callback, cleanup, delete, interpreter