/*
 * V4L2 Codec decoding example application
 * Kamil Debski <k.debski@samsung.com>
 *
 * Queue handling
 *
 * Copyright 2012 Samsung Electronics Co., Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include "common.h"
#include "queue.h"

#include <pthread.h>
#include <stdlib.h>

int queue_init(struct queue *q, int size)
{
	q->q = (int*)malloc(size * sizeof(int));
	if (!q->q) {
		err("Failed to init queue (malloc failed)");
		return -1;
	}
	q->size = size;
	q->head = 0;
	q->tail = 0;
	q->n = 0;
	pthread_mutex_init(&q->mutex, NULL);
	return 0;
}

int queue_add(struct queue *q, int e)
{
	pthread_mutex_lock(&q->mutex);
	if (q->n >= q->size) {
		pthread_mutex_unlock(&q->mutex);
		return -1;
	}
	q->q[q->head] = e;
	q->head++;
	q->head %= q->size;
	q->n++;
	pthread_mutex_unlock(&q->mutex);
	return 0;
}

int queue_remove(struct queue *q)
{
	int x;
	pthread_mutex_lock(&q->mutex);
	if (q->n == 0) {
		pthread_mutex_unlock(&q->mutex);
		return -1;
	}
	x = q->q[q->tail];
	q->tail++;
	q->tail %= q->size;
	q->n--;
	pthread_mutex_unlock(&q->mutex);
	return x;
}

int queue_empty(struct queue *q)
{
	int x;
	pthread_mutex_lock(&q->mutex);
	x = (q->n == 0);
	pthread_mutex_unlock(&q->mutex);
	return x;
}

void queue_free(struct queue *q)
{
	free(q->q);
	pthread_mutex_destroy(&q->mutex);
}