FFmpeg
pthread_internal.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
6  * License 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 GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #ifndef AVCODEC_PTHREAD_INTERNAL_H
20 #define AVCODEC_PTHREAD_INTERNAL_H
21 
22 #include "avcodec.h"
23 
24 /* H.264 slice threading seems to be buggy with more than 16 threads,
25  * limit the number of threads to 16 for automatic detection */
26 #define MAX_AUTO_THREADS 16
27 
30 
32 void ff_frame_thread_free(AVCodecContext *avctx, int thread_count);
33 
34 #define THREAD_SENTINEL 0 // This forbids putting a mutex/condition variable at the front.
35 /**
36  * Initialize/destroy a list of mutexes/conditions contained in a structure.
37  * The positions of these mutexes/conditions in the structure are given by
38  * their offsets. Because it is undefined behaviour to destroy
39  * an uninitialized mutex/condition, ff_pthread_init() stores the number
40  * of successfully initialized mutexes and conditions in the object itself
41  * and ff_pthread_free() uses this number to destroy exactly the mutexes and
42  * condition variables that have been successfully initialized.
43  *
44  * @param obj The object containing the mutexes/conditions.
45  * @param[in] offsets An array of offsets. Its first member gives the offset
46  * of the variable that contains the count of successfully
47  * initialized mutexes/condition variables; said variable
48  * must be an unsigned int. Two arrays of offsets, each
49  * delimited by a THREAD_SENTINEL follow. The first
50  * contains the offsets of all the mutexes, the second
51  * contains the offsets of all the condition variables.
52  */
53 int ff_pthread_init(void *obj, const unsigned offsets[]);
54 void ff_pthread_free(void *obj, const unsigned offsets[]);
55 
56 /**
57  * Macros to help creating the above lists. mutexes and conds need
58  * to be parentheses-enclosed lists of offsets in the containing structure.
59  */
60 #define OFFSET_ARRAY(...) __VA_ARGS__, THREAD_SENTINEL
61 #define DEFINE_OFFSET_ARRAY(type, name, cnt_variable, mutexes, conds) \
62 static const unsigned name ## _offsets[] = { offsetof(type, cnt_variable), \
63  OFFSET_ARRAY mutexes, \
64  OFFSET_ARRAY conds }
65 
66 #endif // AVCODEC_PTHREAD_INTERNAL_H
ff_slice_thread_init
int ff_slice_thread_init(AVCodecContext *avctx)
Definition: pthread_slice.c:134
ff_pthread_free
void ff_pthread_free(void *obj, const unsigned offsets[])
Definition: pthread.c:94
offsets
static const int offsets[]
Definition: hevc_pel.c:34
ff_frame_thread_free
void ff_frame_thread_free(AVCodecContext *avctx, int thread_count)
Definition: pthread_frame.c:726
ff_pthread_init
int ff_pthread_init(void *obj, const unsigned offsets[])
Initialize/destroy a list of mutexes/conditions contained in a structure.
Definition: pthread.c:107
avcodec.h
ff_frame_thread_init
int ff_frame_thread_init(AVCodecContext *avctx)
Definition: pthread_frame.c:866
AVCodecContext
main external API structure.
Definition: avcodec.h:398
ff_slice_thread_free
void ff_slice_thread_free(AVCodecContext *avctx)
Definition: pthread_slice.c:82