實現:
begin stop ,run:semaphore
stop:=0;run:=0;
cobegin
driver: begin
L1: P(run);
啟動車輛;
正常行車;
到站停車;
V(stop);
goto L1;
end;
conductor:begin
L2:上乘客;
關車門;
V(run);
售票;
P(stop);
開車門;
下乘客;
goto L2;
coend;