source: doc/papers/concurrency/examples/ProdCons.sim@ 10c7f40

BEGIN
        CLASS Consumer( prod );
                REF(Producer) prod; ! constructor parameter;
                HIDDEN p1, p2, status, done, Main;
        BEGIN
                INTEGER p1, p2, status;
                BOOLEAN done;
                PROCEDURE main;
                BEGIN
                        INTEGER money, receipt;

                        money := 1;
                        WHILE NOT done DO BEGIN
                                OutText( "cons receives: " );
                                OutInt( p1, 3 );
                                OutText( ", " );
                                OutInt( p2, 3 );
                                status := status + 1;
                                OutText( " and pays $" );
                                OutInt( money, 3 ); OutImage;
                                receipt := prod.payment( money );
                                OutText( "cons receipt #" );
                                OutInt( receipt, 3 ); OutImage;
                                money := money + 1;
                        END;
                        OutText( "cons stops" ); OutImage;
                END;
                INTEGER PROCEDURE delivery( p1p, p2p );
                        INTEGER p1p, p2p;
                BEGIN
                        p1 := p1p;
                        p2 := p2p;
                        Resume( THIS Consumer );
                        delivery := status;
                END;
                PROCEDURE stop;
                BEGIN
                        done := TRUE;
                        Call( THIS Consumer );
                END;
                ! Consumer constructor code;
                status := 0;
                done := FALSE;
                Detach;
                main;
        END Consumer;

        CLASS Producer;
                HIDDEN cons, N, money, receipt, Main;
        BEGIN
                REF(Consumer) cons;
                INTEGER N, money, receipt;
                PROCEDURE main;
                BEGIN
                        INTEGER i, p1, p2, status;

                        FOR i := 1 STEP 1 UNTIL N DO BEGIN  
                                p1 := RandInt( 1, 100, p1 );
                                p2 := RandInt( 1, 100, p2 );
                                OutText( "prod delivers: " );
                                OutInt( p1, 3 ); OutText( ", " );
                                OutInt( p2, 3 ); OutImage;
                                status := cons.delivery( p1, p2 );
                                OutText( "prod status: " );
                                OutInt( status, 3 ); OutImage;
                        END;
                        cons.stop;
                        OutText( "prod stops" ); OutImage;
                END;
                INTEGER PROCEDURE payment( moneyp );
                        INTEGER moneyp;
                BEGIN
                        money := moneyp;
                        OutText( "prod payment of $" );
                        OutInt( money, 3 ); OutImage;
                        Resume( THIS Producer );
                        receipt := receipt + 1;
                        payment := receipt;
                END;
                PROCEDURE start( Np, consp );
                        INTEGER Np;
                        REF(Consumer) consp;
                BEGIN
                        N := Np;
                        cons :- consp;
                        Resume( THIS Producer );
                END;
                ! Producer constructor code;
                receipt := 0;
                Detach;
                main;
        END Producer;
        ! program main equivalent;
        REF(Producer) prod;
        REF(Consumer) cons;
        prod :- NEW Producer;
        cons :- NEW Consumer( prod );
        prod.start( 5, cons );
END;

! Local Variables: ;
! tab-width: 4 ;
! compile-command: "cim ProdCons.sim" ;
! End: ;