void queue_push(QUEUE q, VALUE v) {
if (queue_empty(q)) {
q->head = q->tail = make_queue_node(v, NULL, NULL);
}
else {
QUEUE_NODE n = make_queue_node(v, tail, NULL);
q->tail->next = n;
q->tail = n;
}
}
/**
* Adds an item to the specified queue
* @returns 1 on success, 0 on failure
*/
int enqueue(queue_t* queue, void* data) {
queue_node_t* new_node;
new_node = make_queue_node(data);
if (new_node == NULL) {
return 0;
}
sem_wait(queue->limit_sem);
pthread_mutex_lock(&queue->mutex);
// If queue is empty
if (queue->head == NULL) {
assert(queue->tail == NULL);
queue->head = new_node;
queue->tail = new_node;
pthread_mutex_unlock(&queue->mutex);
sem_post(queue->fill_sem);
return 1;
}
// If queue already has something in it
assert(queue->tail->next == NULL);
new_node->prev = queue->tail;
queue->tail->next = new_node;
queue->tail = new_node;
pthread_mutex_unlock(&queue->mutex);
sem_post(queue->fill_sem);
return 1;
}
