calldel(3Tcl)

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 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