| 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 | |
| 22 | typedef struct AVThreadMessageQueue AVThreadMessageQueue; |
| 23 | |
| 24 | typedef enum AVThreadMessageFlags { |
| 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 | */ |
| 31 | AV_THREAD_MESSAGE_NONBLOCK = 1, |
| 32 | |
| 33 | } AVThreadMessageFlags; |
| 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 | */ |
| 44 | int av_thread_message_queue_alloc(AVThreadMessageQueue **mq, |
| 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 | */ |
| 53 | void av_thread_message_queue_free(AVThreadMessageQueue **mq); |
| 54 | |
| 55 | /** |
| 56 | * Send a message on the queue. |
| 57 | */ |
| 58 | int av_thread_message_queue_send(AVThreadMessageQueue *mq, |
| 59 | void *msg, |
| 60 | unsigned flags); |
| 61 | |
| 62 | /** |
| 63 | * Receive a message from the queue. |
| 64 | */ |
| 65 | int av_thread_message_queue_recv(AVThreadMessageQueue *mq, |
| 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_recv() will |
| 73 | * return it immediately when there are no longer available messages. |
| 74 | * Conventional values, such as AVERROR_EOF or AVERROR(EAGAIN), can be used |
| 75 | * to cause the receiving thread to stop or suspend its operation. |
| 76 | */ |
| 77 | void av_thread_message_queue_set_err_send(AVThreadMessageQueue *mq, |
| 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_send() will |
| 84 | * return it immediately. Conventional values, such as AVERROR_EOF or |
| 85 | * AVERROR(EAGAIN), can be used to cause the sending thread to stop or |
| 86 | * suspend its operation. |
| 87 | */ |
| 88 | void av_thread_message_queue_set_err_recv(AVThreadMessageQueue *mq, |
| 89 | int err); |
| 90 | |
| 91 | #endif /* AVUTIL_THREADMESSAGE_H */ |