Files
ustreamer/janus/src/queue.c
Maxim Devaev 0f753dc654 queue fix
2022-06-06 02:04:16 +03:00

93 lines
3.3 KiB
C

/*****************************************************************************
# #
# uStreamer - Lightweight and fast MJPEG-HTTP streamer. #
# #
# Copyright (C) 2018-2022 Maxim Devaev <mdevaev@gmail.com> #
# #
# This program is free software: you can redistribute it and/or modify #
# it under the terms of the GNU General Public License as published by #
# the Free Software Foundation, either version 3 of the License, or #
# (at your option) any later version. #
# #
# This program 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 General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with this program. If not, see <https://www.gnu.org/licenses/>. #
# #
*****************************************************************************/
#include "queue.h"
queue_s *queue_init(unsigned capacity) {
queue_s *queue;
A_CALLOC(queue, 1);
A_CALLOC(queue->items, capacity);
queue->capacity = capacity;
A_MUTEX_INIT(&queue->mutex);
pthread_condattr_t attrs;
assert(!pthread_condattr_init(&attrs));
assert(!pthread_condattr_setclock(&attrs, CLOCK_MONOTONIC));
assert(!pthread_cond_init(&queue->full_cond, &attrs));
assert(!pthread_cond_init(&queue->empty_cond, &attrs));
assert(!pthread_condattr_destroy(&attrs));
return queue;
}
void queue_destroy(queue_s *queue) {
free(queue->items);
free(queue);
}
#define WAIT_OR_UNLOCK(_var, _cond) { \
struct timespec ts; \
assert(!clock_gettime(CLOCK_MONOTONIC, &ts)); \
ts.tv_sec += timeout; \
while (_var) { \
int err = pthread_cond_timedwait(_cond, &queue->mutex, &ts); \
if (err == ETIMEDOUT) { \
A_MUTEX_UNLOCK(&queue->mutex); \
return -1; \
} \
assert(!err); \
} \
}
int queue_put(queue_s *queue, void *item, unsigned timeout) {
A_MUTEX_LOCK(&queue->mutex);
WAIT_OR_UNLOCK(queue->size == queue->capacity, &queue->full_cond);
queue->items[queue->in] = item;
++queue->size;
++queue->in;
queue->in %= queue->capacity;
A_MUTEX_UNLOCK(&queue->mutex);
assert(!pthread_cond_broadcast(&queue->empty_cond));
return 0;
}
int queue_get(queue_s *queue, void **item, unsigned timeout) {
A_MUTEX_LOCK(&queue->mutex);
WAIT_OR_UNLOCK(queue->size == 0, &queue->empty_cond);
*item = queue->items[queue->out];
--queue->size;
++queue->out;
queue->out %= queue->capacity;
A_MUTEX_UNLOCK(&queue->mutex);
assert(!pthread_cond_broadcast(&queue->full_cond));
return 0;
}
#undef WAIT_OR_UNLOCK
int queue_get_free(queue_s *queue) {
A_MUTEX_LOCK(&queue->mutex);
unsigned size = queue->size;
A_MUTEX_UNLOCK(&queue->mutex);
return queue->capacity - size;
}