예제 #1
0
//Each elevator is a while loop. 
//Check the global list and if it’s empty, block on the condition variable for blocking elevators. 
//When the elevator gets a person to service, it moves to the appropriate flo0or and opens its door. 
//It puts itself into the person’s e field, then signals the person and blocks until the person wakes it up. 
//When it wakes up, it goes to the person’s destination floor, opens its door, signals the person and blocks. 
//When the person wakes it up, it closes its door and re-executes its while loop.
//• Your elevator’s should call open door(), close door() from move to floor() appropriately. 
//All sleeping and printing should be done in elevator skeleton.c. 
//Thus, your final program that you hand in should not do any sleeping or any printing.
void *elevator(void *arg)
{
    Person *person_in_transit;
    for(;;)
    {

        pthread_mutex_lock(((Elevator*)arg)->es->lock);
        while (!((Queue*)((Elevator*)arg)->es->v)->count)
            pthread_cond_wait(((Queue*)((Elevator*)arg)->es->v)->cond, ((Elevator*)arg)->es->lock);
            if(!dll_empty(((Queue*)((Elevator*)arg)->es->v)->passengers)){
             person_in_transit = (Person*)jval_v(dll_val(dll_first(((Queue*)((Elevator*)arg)->es->v)->passengers)));
             dll_delete_node(dll_first(((Queue*)((Elevator*)arg)->es->v)->passengers));
            }
        // unlock the critial section.
        pthread_mutex_unlock(((Elevator*)arg)->es->lock);
       //move the elevator.
        --((Queue*)((Elevator*)arg)->es->v)->count;
        person_in_transit->from == ((Elevator*)arg)->onfloor?:move_to_floor(((Elevator*)arg), person_in_transit->from);
        //open the door
        open_door(((Elevator*)arg));
        //add the people to the elevator
        person_in_transit->e = ((Elevator*)arg); 
        //signal the person
        pthread_mutex_lock(person_in_transit->lock);
        pthread_cond_signal(person_in_transit->cond);
        pthread_mutex_unlock(person_in_transit->lock);
        // have the elevator wait
        pthread_mutex_lock(((Elevator*)arg)->lock);
        pthread_cond_wait(((Elevator*)arg)->cond, ((Elevator*)arg)->lock);
        pthread_mutex_unlock(((Elevator*)arg)->lock);
        // close door 
        close_door(((Elevator*)arg));
        // elevator moves
        move_to_floor(person_in_transit->e,person_in_transit->to);
        // open the door once move has completed.
        open_door(((Elevator*)arg));
        // signal the person
        pthread_mutex_lock(person_in_transit->lock);
        pthread_cond_signal(person_in_transit->cond);
        pthread_mutex_unlock(person_in_transit->lock);
        // block the elevator
        pthread_mutex_lock(((Elevator*)arg)->lock);
        pthread_cond_wait(((Elevator*)arg)->cond, ((Elevator*)arg)->lock);
        pthread_mutex_unlock(((Elevator*)arg)->lock);
        // close the door
        close_door(((Elevator*)arg));
        // restart. 
    }
}
예제 #2
0
task main()
{
	move_to_bottom();

	wait1Msec(2000);

	do{
		if(SensorValue(floor_1) == 1){
			move_to_floor(current_floor(), FIRST);

		}

		else if(SensorValue(floor_2) == 1){
			move_to_floor(current_floor(), SECOND);
		}

		else if(SensorValue(floor_3) == 1){
			move_to_floor(current_floor(), THIRD);
		}
	}while(true);

	move_motors(0);
}
예제 #3
0
void *elevator(void *arg){
    Elevator *e = (Elevator *) arg; 
    Dllist item, next, pickup;
    Person *p;
    int direction = 1;
    pickup = new_dllist();

    while(1){

        if(e -> onfloor >= top) direction = -1;
        else if(e -> onfloor <= 1) direction = 1;
        //printf("\tElevator[%i] on floor %i going %s:\n",
        //        e -> id, e -> onfloor, direction == 1 ? "up": "down"); 

        /* pick people up */
        pthread_mutex_lock(lock);

        item = dll_first(people);
        while(!dll_empty(people) && item != dll_nil(people)){
            next = dll_next(item);
            p = (Person *) item -> val.v;

            //printf("\t\tShould I get %s %s going from %i to %i? ",
            //        p -> fname, p -> lname, p -> from, p -> to);

            if(e -> onfloor == p -> from){
                if(p -> to > e -> onfloor && direction == 1 || 
                   p -> to < e -> onfloor && direction == -1){
                    dll_append(pickup, item -> val);
                    dll_delete_node(item);
                    //printf("yes!\n");

                }
                //else printf("no!\n");
            }
            //else printf("no!\n");

            item = next;
        }

        pthread_mutex_unlock(lock);

        item = dll_first(pickup);
        while(!dll_empty(pickup) && item != dll_nil(pickup)){
            next = dll_next(item);
            p = (Person *) item -> val.v;

            if(!e -> door_open) open_door(e);
            pthread_mutex_lock(p -> lock);

            p -> e = e;

            pthread_cond_signal(p -> cond);
            pthread_mutex_lock(e -> lock);
            pthread_mutex_unlock(p -> lock);

            pthread_cond_wait(e -> cond, e -> lock);
            pthread_mutex_unlock(e -> lock);

            dll_delete_node(item);
            item = next;
        }
        if(e -> door_open) close_door(e);

        move_to_floor(e, e -> onfloor + direction);

        /* drop people off */
        item = dll_first(e -> people);
        while(!dll_empty(e -> people) && item != dll_nil(e -> people)){
            next = dll_next(item);
            p = (Person *) item -> val.v;

            if(p -> to == e -> onfloor){
               if(!e -> door_open) open_door(e);
                
               pthread_mutex_lock(p -> lock);
               pthread_cond_signal(p -> cond);
               pthread_mutex_lock(e -> lock);
               pthread_mutex_unlock(p -> lock);

               pthread_cond_wait(e -> cond, e -> lock);
               pthread_mutex_unlock(e -> lock);
            }

            item = next;
        }
        //if(e -> door_open) close_door(e);

    }

    return NULL;
}