5 struct QueueItem * head;
6 struct QueueItem * tail;
12 struct QueueItem * next;
13 struct QueueItem * prev;
16 struct Queue * createQueue();
17 struct QueueItem * addNewItem(struct Queue * queue, void * ptr);
18 void removeItem(struct Queue * queue, struct QueueItem * item);
19 int isEmpty(struct Queue *queue);
20 struct QueueItem * getTail(struct Queue * queue);