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-- C97114A.ADA

--                             Grant of Unlimited Rights

--

--     Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687,

--     F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained 

--     unlimited rights in the software and documentation contained herein.

--     Unlimited rights are defined in DFAR 252.227-7013(a)(19).  By making 

--     this public release, the Government intends to confer upon all 

--     recipients unlimited rights  equal to those held by the Government.  

--     These rights include rights to use, duplicate, release or disclose the 

--     released technical data and computer software in whole or in part, in 

--     any manner and for any purpose whatsoever, and to have or permit others 

--     to do so.

--

--                                    DISCLAIMER

--

--     ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR

--     DISCLOSED ARE AS IS.  THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED 

--     WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE

--     SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE 

--     OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A

--     PARTICULAR PURPOSE OF SAID MATERIAL.

--*

-- CHECK WHETHER A DELAY EXPRESSION FOLLOWING AN OPEN GUARD IS EVALUATED

-- DIRECTLY AFTER THE GUARD OR ONLY AFTER ALL GUARDS HAVE BEEN

-- EVALUATED, OR IN SOME MIXED ORDER SUCH THAT DELAY EXPRESSIONS ARE

-- EVALUATED AFTER THEIR GUARDS ARE DETERMINED TO BE OPEN.

-- RM 5/10/82

-- SPS 11/21/82

-- JBG 10/24/83

-- PWN 09/11/94  REMOVED PRAGMA PRIORITY FOR ADA 9X.

with Impdef;

WITH REPORT; USE REPORT;

WITH SYSTEM; USE SYSTEM;

PROCEDURE C97114A IS

     -- THE TASK WILL HAVE LAST PRIORITY ( PRIORITY'FIRST )

     EVAL_ORDER  :  STRING (1..6)       := ( 1..6 => '*' );

     EVAL_ORD    :  STRING (1..6)       := ( 1..6 => '*' );

     INDEX       :  INTEGER             := 0;

     DUMMY       :  INTEGER             := 0;

     FUNCTION F1 (X:INTEGER) RETURN INTEGER IS

     BEGIN

          INDEX := INDEX + 1;

          EVAL_ORDER (INDEX) := 'F';    -- 123: FGH

          EVAL_ORD   (INDEX) := 'G';    -- 123: GGG ( 'G' FOR 'GUARD' )

          RETURN ( IDENT_INT(7) );

     END F1;

     FUNCTION F2 (X:INTEGER) RETURN INTEGER IS

     BEGIN

          INDEX := INDEX + 1;

          EVAL_ORDER (INDEX) := 'G';

          EVAL_ORD   (INDEX) := 'G';

          RETURN ( IDENT_INT(7) );

     END F2;

     FUNCTION F3 (X:INTEGER) RETURN INTEGER IS

     BEGIN

          INDEX := INDEX + 1;

          EVAL_ORDER (INDEX) := 'H';

          EVAL_ORD   (INDEX) := 'G';

          RETURN ( IDENT_INT(7) );

     END F3;

     FUNCTION  D1( X:INTEGER )  RETURN DURATION IS

     BEGIN

          INDEX := INDEX + 1;

          EVAL_ORDER (INDEX) := 'A';    -- 123: ABC

          EVAL_ORD   (INDEX) := 'D';    -- 123: DDD ( 'D' FOR 'DELAY' )

          RETURN ( 1.0 );

     END D1;

     FUNCTION  D2( X:INTEGER )  RETURN DURATION IS

     BEGIN

          INDEX := INDEX + 1;

          EVAL_ORDER (INDEX) := 'B';

          EVAL_ORD   (INDEX) := 'D';

          RETURN ( 2.0 );

     END D2;

     FUNCTION  D3( X:INTEGER )  RETURN DURATION IS

     BEGIN

          INDEX := INDEX + 1;

          EVAL_ORDER (INDEX) := 'C';

          EVAL_ORD   (INDEX) := 'D';

          RETURN ( 3.0 );

     END D3;

     FUNCTION POS_OF (FUNC : CHARACTER) RETURN INTEGER  IS

     BEGIN

          FOR I IN EVAL_ORDER'RANGE LOOP

               IF EVAL_ORDER(I) = FUNC THEN

                    RETURN I;

               END IF;

          END LOOP;

          FAILED ("DID NOT FIND LETTER " & FUNC);

          RETURN 0;

     END POS_OF;

BEGIN

     TEST ("C97114A", "CHECK THAT THE DELAY EXPRESSIONS ARE" &

                      " EVALUATED AFTER THE GUARDS BUT"      &

                      " BEFORE THE RENDEZVOUS IS ATTEMPTED"  );

     DECLARE

          TASK T IS

               ENTRY E1;

          END T;

          TASK BODY T IS

          BEGIN

               WHILE  E1'COUNT = 0  -- IF  E1  NOT YET CALLED, THEN GIVE

               LOOP                 --     THE MAIN TASK AN OPPORTUNITY

                    DELAY  10.01 * Impdef.One_Second;   --     TO ISSUE THE CALL.

               END LOOP;

               SELECT

                         ACCEPT  E1;

               OR

                    WHEN  6 + F1(7) = 13  =>

                         DELAY  D1( DUMMY ) * Impdef.One_Second;

               OR

                    WHEN  6 + F2(7) = 13  =>

                         DELAY  D2( DUMMY ) * Impdef.One_Second;

               OR

                    WHEN  6 + F3(7) = 13  =>

                         DELAY  D3( DUMMY ) * Impdef.One_Second;

               END SELECT;

          END T;

     BEGIN

          T.E1;

     END; -- END OF BLOCK CONTAINING THE ENTRY CALLS

     COMMENT ("EVALUATIONS WERE DONE IN THE ORDER " & EVAL_ORD);

     COMMENT ("FUNCTIONS WERE CALLED IN THE ORDER " & EVAL_ORDER);

     IF EVAL_ORD = "GGGDDD" THEN

          COMMENT ("ALL GUARDS EVALUATED FIRST");

     ELSIF EVAL_ORD = "GDGDGD" THEN

          COMMENT ("DELAY EXPRESSION EVALUATED AFTER EACH GUARD");

     END IF;

-- CHECK THAT GUARDS ARE ALWAYS EVALUATED BEFORE DELAY EXPRESSIONS

     IF   POS_OF ('F') > POS_OF ('A') OR

          POS_OF ('G') > POS_OF ('B') OR

          POS_OF ('H') > POS_OF ('C') THEN

               FAILED ("A DELAY EXPRESSION WAS EVALUATED BEFORE ITS " &

                       "GUARD");

     END IF;

     RESULT;

END  C97114A;