(* Copyright (C) 1989, Digital Equipment Corporation           *)
(* All rights reserved.                                        *)
(* See the file COPYRIGHT for a full description.              *)

(* Last modified on Tue Jun 26 00:26:24 1990 by muller         *)
(*      modified on Wed Apr 12 08:48:03 1989 by kalsow         *)

INTERFACE ThreadSup;

IMPORT Thread;

(* The variables below are local to each thread. More precisely, there is
   one location corresponding for each of these variable, but they are
   modified whenever switching occurs.

   handlers is used by the runtime system to store the head of the list of
   active handlers. stackLimit is used by the runtime to store the top
   of the stack and thus check stack overflow.
   These are not declared because we need declarations
	  extern char * _ThreadAs__stackLimit;
	  extern HANDLER * _ThreadAs__handlers;
   in most of the modules (via M3RuntimeDecls.h). But this declaration would
   conflict with the declaration produced by the compiler for modules which
   import ThreadSup. And the only client today is Thread.m3 that does not
   need explicit access to these variables. So we do not declare them in 
   the Modula world. *)

VAR
  self: Thread.T;
  (* stackLimit: ADDRESS; *)
  (* handlers: ADDRESS; *)

VAR
  inCritical: INTEGER;

<*EXTERNAL*>
VAR
  contextSize: INTEGER;

<*EXTERNAL*>
PROCEDURE InitTopContext (t: Thread.T; context: ADDRESS);

<*EXTERNAL*> 
PROCEDURE InitContext (t: Thread.T; context, stack: ADDRESS; size: INTEGER);

<*EXTERNAL*>
PROCEDURE Transfer (context: ADDRESS);

<*EXTERNAL*>
PROCEDURE Tos (context: ADDRESS; VAR start, stop: ADDRESS);

<*EXTERNAL*>
PROCEDURE SelfTos (VAR start, stop: ADDRESS);


<*EXTERNAL*>
PROCEDURE UserMain (self: Thread.Closure): REFANY;

END ThreadSup.