/*
* This file is part of libbluray
* Copyright (C) 2010-2016 Petri Hintukainen <phintuka@users.sourceforge.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include "event_queue.h"
#include "util/macro.h"
#include "util/mutex.h"
#include <string.h>
#define MAX_EVENTS 31 /* 2^n - 1 */
struct bd_event_queue {
BD_MUTEX mutex;
size_t event_size;
unsigned in; /* next free slot */
unsigned out; /* next event */
unsigned char ev[1];
};
void event_queue_destroy(BD_EVENT_QUEUE **pp)
{
if (pp && *pp) {
BD_EVENT_QUEUE *eq = *pp;
bd_mutex_destroy(&eq->mutex);
X_FREE(*pp);
}
}
BD_EVENT_QUEUE *event_queue_new(size_t event_size)
{
BD_EVENT_QUEUE *eq = calloc(1, sizeof(BD_EVENT_QUEUE) + event_size * (MAX_EVENTS + 1));
if (eq) {
bd_mutex_init(&eq->mutex);
eq->event_size = event_size;
}
return eq;
}
int event_queue_get(BD_EVENT_QUEUE *eq, void *ev)
{
int result = 0;
if (eq) {
bd_mutex_lock(&eq->mutex);
if (eq->in != eq->out) {
memcpy(ev, &eq->ev[eq->out * eq->event_size], eq->event_size);
eq->out = (eq->out + 1) & MAX_EVENTS;
result = 1;
}
bd_mutex_unlock(&eq->mutex);
}
return result;
}
int event_queue_put(BD_EVENT_QUEUE *eq, const void *ev)
{
int result = 0;
if (eq) {
bd_mutex_lock(&eq->mutex);
unsigned new_in = (eq->in + 1) & MAX_EVENTS;
if (new_in != eq->out) {
memcpy(&eq->ev[eq->in * eq->event_size], ev, eq->event_size);
eq->in = new_in;
result = 1;
}
bd_mutex_unlock(&eq->mutex);
}
return result;
}