FFmpeg
pthread_slice.c
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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 /**
20  * @file
21  * Slice multithreading support functions
22  * @see doc/multithreading.txt
23  */
24 
25 #include "config.h"
26 
27 #include "avcodec.h"
28 #include "internal.h"
29 #include "pthread_internal.h"
30 #include "thread.h"
31 
32 #include "libavutil/avassert.h"
33 #include "libavutil/common.h"
34 #include "libavutil/cpu.h"
35 #include "libavutil/mem.h"
36 #include "libavutil/thread.h"
37 #include "libavutil/slicethread.h"
38 
39 typedef int (action_func)(AVCodecContext *c, void *arg);
40 typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);
42 
43 typedef struct SliceThreadContext {
48  void *args;
49  int *rets;
50  int job_size;
51 
52  int *entries;
58 
59 static void main_function(void *priv) {
60  AVCodecContext *avctx = priv;
62  c->mainfunc(avctx);
63 }
64 
65 static void worker_func(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads)
66 {
67  AVCodecContext *avctx = priv;
69  int ret;
70 
71  ret = c->func ? c->func(avctx, (char *)c->args + c->job_size * jobnr)
72  : c->func2(avctx, c->args, jobnr, threadnr);
73  if (c->rets)
74  c->rets[jobnr] = ret;
75 }
76 
78 {
80  int i;
81 
83 
84  for (i = 0; i < c->thread_count; i++) {
87  }
88 
89  av_freep(&c->entries);
92  av_freep(&avctx->internal->thread_ctx);
93 }
94 
95 static int thread_execute(AVCodecContext *avctx, action_func* func, void *arg, int *ret, int job_count, int job_size)
96 {
98 
99  if (!(avctx->active_thread_type&FF_THREAD_SLICE) || avctx->thread_count <= 1)
100  return avcodec_default_execute(avctx, func, arg, ret, job_count, job_size);
101 
102  if (job_count <= 0)
103  return 0;
104 
105  c->job_size = job_size;
106  c->args = arg;
107  c->func = func;
108  c->rets = ret;
109 
110  avpriv_slicethread_execute(c->thread, job_count, !!c->mainfunc );
111  return 0;
112 }
113 
114 static int thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
115 {
117  c->func2 = func2;
118  return thread_execute(avctx, NULL, arg, ret, job_count, 0);
119 }
120 
122 {
124  c->func2 = func2;
125  c->mainfunc = mainfunc;
126  return thread_execute(avctx, NULL, arg, ret, job_count, 0);
127 }
128 
130 {
132  int thread_count = avctx->thread_count;
133  static void (*mainfunc)(void *);
134 
135  // We cannot do this in the encoder init as the threads are created before
136  if (av_codec_is_encoder(avctx->codec) &&
137  avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO &&
138  avctx->height > 2800)
139  thread_count = avctx->thread_count = 1;
140 
141  if (!thread_count) {
142  int nb_cpus = av_cpu_count();
143  if (avctx->height)
144  nb_cpus = FFMIN(nb_cpus, (avctx->height+15)/16);
145  // use number of cores + 1 as thread count if there is more than one
146  if (nb_cpus > 1)
147  thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
148  else
149  thread_count = avctx->thread_count = 1;
150  }
151 
152  if (thread_count <= 1) {
153  avctx->active_thread_type = 0;
154  return 0;
155  }
156 
157  avctx->internal->thread_ctx = c = av_mallocz(sizeof(*c));
159  if (!c || (thread_count = avpriv_slicethread_create(&c->thread, avctx, worker_func, mainfunc, thread_count)) <= 1) {
160  if (c)
162  av_freep(&avctx->internal->thread_ctx);
163  avctx->thread_count = 1;
164  avctx->active_thread_type = 0;
165  return 0;
166  }
167  avctx->thread_count = thread_count;
168 
169  avctx->execute = thread_execute;
170  avctx->execute2 = thread_execute2;
171  return 0;
172 }
173 
175 {
177  int *entries = p->entries;
178 
179  pthread_mutex_lock(&p->progress_mutex[thread]);
180  entries[field] +=n;
181  pthread_cond_signal(&p->progress_cond[thread]);
183 }
184 
186 {
188  int *entries = p->entries;
189 
190  if (!entries || !field) return;
191 
192  thread = thread ? thread - 1 : p->thread_count - 1;
193 
194  pthread_mutex_lock(&p->progress_mutex[thread]);
195  while ((entries[field - 1] - entries[field]) < shift){
196  pthread_cond_wait(&p->progress_cond[thread], &p->progress_mutex[thread]);
197  }
199 }
200 
202 {
203  int i;
204 
205  if (avctx->active_thread_type & FF_THREAD_SLICE) {
207 
208  if (p->entries) {
209  av_assert0(p->thread_count == avctx->thread_count);
210  av_freep(&p->entries);
211  }
212 
213  p->thread_count = avctx->thread_count;
214  p->entries = av_mallocz_array(count, sizeof(int));
215 
216  if (!p->progress_mutex) {
219  }
220 
221  if (!p->entries || !p->progress_mutex || !p->progress_cond) {
222  av_freep(&p->entries);
224  av_freep(&p->progress_cond);
225  return AVERROR(ENOMEM);
226  }
227  p->entries_count = count;
228 
229  for (i = 0; i < p->thread_count; i++) {
232  }
233  }
234 
235  return 0;
236 }
237 
239 {
241  memset(p->entries, 0, p->entries_count * sizeof(int));
242 }
#define NULL
Definition: coverity.c:32
const struct AVCodec * codec
Definition: avcodec.h:1574
int ff_slice_thread_init(AVCodecContext *avctx)
static int shift(int a, int b)
Definition: sonic.c:82
static av_always_inline int pthread_mutex_destroy(pthread_mutex_t *mutex)
Definition: os2threads.h:108
#define pthread_mutex_lock(a)
Definition: ffprobe.c:61
static av_always_inline int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
Definition: os2threads.h:166
int av_cpu_count(void)
Definition: cpu.c:267
Memory handling functions.
static void worker_func(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads)
Definition: pthread_slice.c:65
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:236
void ff_thread_await_progress2(AVCodecContext *avctx, int field, int thread, int shift)
static av_always_inline int pthread_cond_destroy(pthread_cond_t *cond)
Definition: os2threads.h:140
int av_codec_is_encoder(const AVCodec *codec)
Definition: utils.c:94
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
struct AVSliceThread AVSliceThread
Definition: slicethread.h:22
void * thread_ctx
Definition: internal.h:163
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
Multithreading support functions.
pthread_mutex_t * progress_mutex
Definition: pthread_slice.c:56
static void main_function(void *priv)
Definition: pthread_slice.c:59
static av_always_inline int pthread_cond_signal(pthread_cond_t *cond)
Definition: os2threads.h:148
int( action_func)(AVCodecContext *c, void *arg)
Definition: pthread_slice.c:39
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this field
int active_thread_type
Which multithreading methods are in use by the codec.
Definition: avcodec.h:2843
AVSliceThread * thread
Definition: pthread_slice.c:44
action_func2 * func2
Definition: pthread_slice.c:46
const char * arg
Definition: jacosubdec.c:66
simple assert() macros that are a bit more flexible than ISO C assert().
GLsizei count
Definition: opengl_enc.c:108
action_func * func
Definition: pthread_slice.c:45
int ff_alloc_entries(AVCodecContext *avctx, int count)
static int thread_execute2(AVCodecContext *avctx, action_func2 *func2, void *arg, int *ret, int job_count)
#define FFMIN(a, b)
Definition: common.h:96
void avpriv_slicethread_free(AVSliceThread **pctx)
Destroy slice threading context.
Definition: slicethread.c:250
void ff_slice_thread_free(AVCodecContext *avctx)
Definition: pthread_slice.c:77
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int( main_func)(AVCodecContext *c)
Definition: pthread_slice.c:41
static av_always_inline int pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
Definition: os2threads.h:100
#define FF_THREAD_SLICE
Decode more than one part of a single frame at once.
Definition: avcodec.h:2836
pthread_cond_t * progress_cond
Definition: pthread_slice.c:55
int n
Definition: avisynth_c.h:760
#define pthread_mutex_unlock(a)
Definition: ffprobe.c:65
int thread_count
thread count is used to decide how many independent tasks should be passed to execute() ...
Definition: avcodec.h:2824
if(ret)
void ff_reset_entries(AVCodecContext *avctx)
int(* execute2)(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count)
The codec may call this to execute several independent things.
Definition: avcodec.h:2884
Libavcodec external API header.
void ff_thread_report_progress2(AVCodecContext *avctx, int field, int thread, int n)
enum AVCodecID codec_id
Definition: avcodec.h:1575
int avpriv_slicethread_create(AVSliceThread **pctx, void *priv, void(*worker_func)(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads), void(*main_func)(void *priv), int nb_threads)
Create slice threading context.
Definition: slicethread.c:236
main external API structure.
Definition: avcodec.h:1565
void avpriv_slicethread_execute(AVSliceThread *ctx, int nb_jobs, int execute_main)
Execute slice threading.
Definition: slicethread.c:245
int( action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr)
Definition: pthread_slice.c:40
#define MAX_AUTO_THREADS
#define FF_CODEC_CAP_SLICE_THREAD_HAS_MF
Codec initializes slice-based threading with a main function.
Definition: internal.h:70
int
common internal api header.
_fmutex pthread_mutex_t
Definition: os2threads.h:49
common internal and external API header
main_func * mainfunc
Definition: pthread_slice.c:47
int ff_slice_thread_execute_with_mainfunc(AVCodecContext *avctx, action_func2 *func2, main_func *mainfunc, void *arg, int *ret, int job_count)
static av_always_inline int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr)
Definition: os2threads.h:129
int caps_internal
Internal codec capabilities.
Definition: avcodec.h:3607
struct AVCodecInternal * internal
Private context used for internal data.
Definition: avcodec.h:1600
#define av_freep(p)
#define av_malloc_array(a, b)
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
static int thread_execute(AVCodecContext *avctx, action_func *func, void *arg, int *ret, int job_count, int job_size)
Definition: pthread_slice.c:95
int(* execute)(struct AVCodecContext *c, int(*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size)
The codec may call this to execute several independent things.
Definition: avcodec.h:2864
int avcodec_default_execute(AVCodecContext *c, int(*func)(AVCodecContext *c2, void *arg2), void *arg, int *ret, int count, int size)
Definition: utils.c:435
void * av_mallocz_array(size_t nmemb, size_t size)
Definition: mem.c:191