| /* |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg 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. |
| * |
| * FFmpeg 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 FFmpeg; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #ifndef AVUTIL_THREADMESSAGE_H |
| #define AVUTIL_THREADMESSAGE_H |
| |
| typedef struct AVThreadMessageQueue AVThreadMessageQueue; |
| |
| typedef enum AVThreadMessageFlags { |
| |
| /** |
| * Perform non-blocking operation. |
| * If this flag is set, send and recv operations are non-blocking and |
| * return AVERROR(EAGAIN) immediately if they can not proceed. |
| */ |
| AV_THREAD_MESSAGE_NONBLOCK = 1, |
| |
| } AVThreadMessageFlags; |
| |
| /** |
| * Allocate a new message queue. |
| * |
| * @param mq pointer to the message queue |
| * @param nelem maximum number of elements in the queue |
| * @param elsize size of each element in the queue |
| * @return >=0 for success; <0 for error, in particular AVERROR(ENOSYS) if |
| * lavu was built without thread support |
| */ |
| int av_thread_message_queue_alloc(AVThreadMessageQueue **mq, |
| unsigned nelem, |
| unsigned elsize); |
| |
| /** |
| * Free a message queue. |
| * |
| * The message queue must no longer be in use by another thread. |
| */ |
| void av_thread_message_queue_free(AVThreadMessageQueue **mq); |
| |
| /** |
| * Send a message on the queue. |
| */ |
| int av_thread_message_queue_send(AVThreadMessageQueue *mq, |
| void *msg, |
| unsigned flags); |
| |
| /** |
| * Receive a message from the queue. |
| */ |
| int av_thread_message_queue_recv(AVThreadMessageQueue *mq, |
| void *msg, |
| unsigned flags); |
| |
| /** |
| * Set the sending error code. |
| * |
| * If the error code is set to non-zero, av_thread_message_queue_send() will |
| * return it immediately. Conventional values, such as AVERROR_EOF or |
| * AVERROR(EAGAIN), can be used to cause the sending thread to stop or |
| * suspend its operation. |
| */ |
| void av_thread_message_queue_set_err_send(AVThreadMessageQueue *mq, |
| int err); |
| |
| /** |
| * Set the receiving error code. |
| * |
| * If the error code is set to non-zero, av_thread_message_queue_recv() will |
| * return it immediately when there are no longer available messages. |
| * Conventional values, such as AVERROR_EOF or AVERROR(EAGAIN), can be used |
| * to cause the receiving thread to stop or suspend its operation. |
| */ |
| void av_thread_message_queue_set_err_recv(AVThreadMessageQueue *mq, |
| int err); |
| |
| /** |
| * Set the optional free message callback function which will be called if an |
| * operation is removing messages from the queue. |
| */ |
| void av_thread_message_queue_set_free_func(AVThreadMessageQueue *mq, |
| void (*free_func)(void *msg)); |
| |
| /** |
| * Return the current number of messages in the queue. |
| * |
| * @return the current number of messages or AVERROR(ENOSYS) if lavu was built |
| * without thread support |
| */ |
| int av_thread_message_queue_nb_elems(AVThreadMessageQueue *mq); |
| |
| /** |
| * Flush the message queue |
| * |
| * This function is mostly equivalent to reading and free-ing every message |
| * except that it will be done in a single operation (no lock/unlock between |
| * reads). |
| */ |
| void av_thread_message_flush(AVThreadMessageQueue *mq); |
| |
| #endif /* AVUTIL_THREADMESSAGE_H */ |
