FFmpeg 5.1.4
threadmessage.h
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1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public License
6 * as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public License
15 * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#ifndef AVUTIL_THREADMESSAGE_H
20#define AVUTIL_THREADMESSAGE_H
21
23
25
26 /**
27 * Perform non-blocking operation.
28 * If this flag is set, send and recv operations are non-blocking and
29 * return AVERROR(EAGAIN) immediately if they can not proceed.
30 */
32
34
35/**
36 * Allocate a new message queue.
37 *
38 * @param mq pointer to the message queue
39 * @param nelem maximum number of elements in the queue
40 * @param elsize size of each element in the queue
41 * @return >=0 for success; <0 for error, in particular AVERROR(ENOSYS) if
42 * lavu was built without thread support
43 */
45 unsigned nelem,
46 unsigned elsize);
47
48/**
49 * Free a message queue.
50 *
51 * The message queue must no longer be in use by another thread.
52 */
54
55/**
56 * Send a message on the queue.
57 */
59 void *msg,
60 unsigned flags);
61
62/**
63 * Receive a message from the queue.
64 */
66 void *msg,
67 unsigned flags);
68
69/**
70 * Set the sending error code.
71 *
72 * If the error code is set to non-zero, av_thread_message_queue_send() will
73 * return it immediately. Conventional values, such as AVERROR_EOF or
74 * AVERROR(EAGAIN), can be used to cause the sending thread to stop or
75 * suspend its operation.
76 */
78 int err);
79
80/**
81 * Set the receiving error code.
82 *
83 * If the error code is set to non-zero, av_thread_message_queue_recv() will
84 * return it immediately when there are no longer available messages.
85 * Conventional values, such as AVERROR_EOF or AVERROR(EAGAIN), can be used
86 * to cause the receiving thread to stop or suspend its operation.
87 */
89 int err);
90
91/**
92 * Set the optional free message callback function which will be called if an
93 * operation is removing messages from the queue.
94 */
96 void (*free_func)(void *msg));
97
98/**
99 * Return the current number of messages in the queue.
100 *
101 * @return the current number of messages or AVERROR(ENOSYS) if lavu was built
102 * without thread support
103 */
105
106/**
107 * Flush the message queue
108 *
109 * This function is mostly equivalent to reading and free-ing every message
110 * except that it will be done in a single operation (no lock/unlock between
111 * reads).
112 */
114
115#endif /* AVUTIL_THREADMESSAGE_H */
void av_thread_message_queue_set_err_send(AVThreadMessageQueue *mq, int err)
Set the sending error code.
int av_thread_message_queue_recv(AVThreadMessageQueue *mq, void *msg, unsigned flags)
Receive a message from the queue.
int av_thread_message_queue_alloc(AVThreadMessageQueue **mq, unsigned nelem, unsigned elsize)
Allocate a new message queue.
void av_thread_message_queue_set_free_func(AVThreadMessageQueue *mq, void(*free_func)(void *msg))
Set the optional free message callback function which will be called if an operation is removing mess...
void av_thread_message_queue_set_err_recv(AVThreadMessageQueue *mq, int err)
Set the receiving error code.
int av_thread_message_queue_nb_elems(AVThreadMessageQueue *mq)
Return the current number of messages in the queue.
AVThreadMessageFlags
Definition: threadmessage.h:24
@ AV_THREAD_MESSAGE_NONBLOCK
Perform non-blocking operation.
Definition: threadmessage.h:31
int av_thread_message_queue_send(AVThreadMessageQueue *mq, void *msg, unsigned flags)
Send a message on the queue.
void av_thread_message_flush(AVThreadMessageQueue *mq)
Flush the message queue.
void av_thread_message_queue_free(AVThreadMessageQueue **mq)
Free a message queue.
struct AVThreadMessageQueue AVThreadMessageQueue
Definition: threadmessage.h:22