116 lines
3.8 KiB
C
116 lines
3.8 KiB
C
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/*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public License
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* as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef AVUTIL_THREADMESSAGE_H
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#define AVUTIL_THREADMESSAGE_H
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typedef struct AVThreadMessageQueue AVThreadMessageQueue;
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typedef enum AVThreadMessageFlags {
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/**
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* Perform non-blocking operation.
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* If this flag is set, send and recv operations are non-blocking and
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* return AVERROR(EAGAIN) immediately if they can not proceed.
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*/
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AV_THREAD_MESSAGE_NONBLOCK = 1,
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} AVThreadMessageFlags;
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/**
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* Allocate a new message queue.
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*
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* @param mq pointer to the message queue
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* @param nelem maximum number of elements in the queue
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* @param elsize size of each element in the queue
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* @return >=0 for success; <0 for error, in particular AVERROR(ENOSYS) if
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* lavu was built without thread support
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*/
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int av_thread_message_queue_alloc(AVThreadMessageQueue **mq,
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unsigned nelem,
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unsigned elsize);
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/**
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* Free a message queue.
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*
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* The message queue must no longer be in use by another thread.
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*/
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void av_thread_message_queue_free(AVThreadMessageQueue **mq);
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/**
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* Send a message on the queue.
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*/
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int av_thread_message_queue_send(AVThreadMessageQueue *mq,
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void *msg,
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unsigned flags);
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/**
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* Receive a message from the queue.
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*/
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int av_thread_message_queue_recv(AVThreadMessageQueue *mq,
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void *msg,
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unsigned flags);
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/**
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* Set the sending error code.
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*
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* If the error code is set to non-zero, av_thread_message_queue_send() will
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* return it immediately. Conventional values, such as AVERROR_EOF or
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* AVERROR(EAGAIN), can be used to cause the sending thread to stop or
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* suspend its operation.
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*/
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void av_thread_message_queue_set_err_send(AVThreadMessageQueue *mq,
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int err);
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/**
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* Set the receiving error code.
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*
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* If the error code is set to non-zero, av_thread_message_queue_recv() will
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* return it immediately when there are no longer available messages.
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* Conventional values, such as AVERROR_EOF or AVERROR(EAGAIN), can be used
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* to cause the receiving thread to stop or suspend its operation.
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*/
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void av_thread_message_queue_set_err_recv(AVThreadMessageQueue *mq,
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int err);
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/**
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* Set the optional free message callback function which will be called if an
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* operation is removing messages from the queue.
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*/
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void av_thread_message_queue_set_free_func(AVThreadMessageQueue *mq,
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void (*free_func)(void *msg));
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/**
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* Return the current number of messages in the queue.
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*
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* @return the current number of messages or AVERROR(ENOSYS) if lavu was built
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* without thread support
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*/
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int av_thread_message_queue_nb_elems(AVThreadMessageQueue *mq);
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/**
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* Flush the message queue
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*
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* This function is mostly equivalent to reading and free-ing every message
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* except that it will be done in a single operation (no lock/unlock between
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* reads).
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*/
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void av_thread_message_flush(AVThreadMessageQueue *mq);
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#endif /* AVUTIL_THREADMESSAGE_H */
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