Imported Debian version 2.4.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavfilter / pthread.c
CommitLineData
2ba45a60
DM
1/*
2 *
3 * This file is part of FFmpeg.
4 *
5 * FFmpeg is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * FFmpeg is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with FFmpeg; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20/**
21 * @file
22 * Libavfilter multithreading support
23 */
24
25#include "config.h"
26
27#include "libavutil/common.h"
28#include "libavutil/cpu.h"
29#include "libavutil/mem.h"
30
31#include "avfilter.h"
32#include "internal.h"
33#include "thread.h"
34
35#if HAVE_PTHREADS
36#include <pthread.h>
37#elif HAVE_OS2THREADS
38#include "compat/os2threads.h"
39#elif HAVE_W32THREADS
40#include "compat/w32pthreads.h"
41#endif
42
43typedef struct ThreadContext {
44 AVFilterGraph *graph;
45
46 int nb_threads;
47 pthread_t *workers;
48 avfilter_action_func *func;
49
50 /* per-execute perameters */
51 AVFilterContext *ctx;
52 void *arg;
53 int *rets;
54 int nb_rets;
55 int nb_jobs;
56
57 pthread_cond_t last_job_cond;
58 pthread_cond_t current_job_cond;
59 pthread_mutex_t current_job_lock;
60 int current_job;
61 unsigned int current_execute;
62 int done;
63} ThreadContext;
64
65static void* attribute_align_arg worker(void *v)
66{
67 ThreadContext *c = v;
68 int our_job = c->nb_jobs;
69 int nb_threads = c->nb_threads;
70 unsigned int last_execute = 0;
71 int self_id;
72
73 pthread_mutex_lock(&c->current_job_lock);
74 self_id = c->current_job++;
75 for (;;) {
76 while (our_job >= c->nb_jobs) {
77 if (c->current_job == nb_threads + c->nb_jobs)
78 pthread_cond_signal(&c->last_job_cond);
79
80 while (last_execute == c->current_execute && !c->done)
81 pthread_cond_wait(&c->current_job_cond, &c->current_job_lock);
82 last_execute = c->current_execute;
83 our_job = self_id;
84
85 if (c->done) {
86 pthread_mutex_unlock(&c->current_job_lock);
87 return NULL;
88 }
89 }
90 pthread_mutex_unlock(&c->current_job_lock);
91
92 c->rets[our_job % c->nb_rets] = c->func(c->ctx, c->arg, our_job, c->nb_jobs);
93
94 pthread_mutex_lock(&c->current_job_lock);
95 our_job = c->current_job++;
96 }
97}
98
99static void slice_thread_uninit(ThreadContext *c)
100{
101 int i;
102
103 pthread_mutex_lock(&c->current_job_lock);
104 c->done = 1;
105 pthread_cond_broadcast(&c->current_job_cond);
106 pthread_mutex_unlock(&c->current_job_lock);
107
108 for (i = 0; i < c->nb_threads; i++)
109 pthread_join(c->workers[i], NULL);
110
111 pthread_mutex_destroy(&c->current_job_lock);
112 pthread_cond_destroy(&c->current_job_cond);
113 pthread_cond_destroy(&c->last_job_cond);
114 av_freep(&c->workers);
115}
116
117static void slice_thread_park_workers(ThreadContext *c)
118{
119 while (c->current_job != c->nb_threads + c->nb_jobs)
120 pthread_cond_wait(&c->last_job_cond, &c->current_job_lock);
121 pthread_mutex_unlock(&c->current_job_lock);
122}
123
124static int thread_execute(AVFilterContext *ctx, avfilter_action_func *func,
125 void *arg, int *ret, int nb_jobs)
126{
127 ThreadContext *c = ctx->graph->internal->thread;
128 int dummy_ret;
129
130 if (nb_jobs <= 0)
131 return 0;
132
133 pthread_mutex_lock(&c->current_job_lock);
134
135 c->current_job = c->nb_threads;
136 c->nb_jobs = nb_jobs;
137 c->ctx = ctx;
138 c->arg = arg;
139 c->func = func;
140 if (ret) {
141 c->rets = ret;
142 c->nb_rets = nb_jobs;
143 } else {
144 c->rets = &dummy_ret;
145 c->nb_rets = 1;
146 }
147 c->current_execute++;
148
149 pthread_cond_broadcast(&c->current_job_cond);
150
151 slice_thread_park_workers(c);
152
153 return 0;
154}
155
156static int thread_init_internal(ThreadContext *c, int nb_threads)
157{
158 int i, ret;
159
160 if (!nb_threads) {
161 int nb_cpus = av_cpu_count();
162 // use number of cores + 1 as thread count if there is more than one
163 if (nb_cpus > 1)
164 nb_threads = nb_cpus + 1;
165 else
166 nb_threads = 1;
167 }
168
169 if (nb_threads <= 1)
170 return 1;
171
172 c->nb_threads = nb_threads;
173 c->workers = av_mallocz_array(sizeof(*c->workers), nb_threads);
174 if (!c->workers)
175 return AVERROR(ENOMEM);
176
177 c->current_job = 0;
178 c->nb_jobs = 0;
179 c->done = 0;
180
181 pthread_cond_init(&c->current_job_cond, NULL);
182 pthread_cond_init(&c->last_job_cond, NULL);
183
184 pthread_mutex_init(&c->current_job_lock, NULL);
185 pthread_mutex_lock(&c->current_job_lock);
186 for (i = 0; i < nb_threads; i++) {
187 ret = pthread_create(&c->workers[i], NULL, worker, c);
188 if (ret) {
189 pthread_mutex_unlock(&c->current_job_lock);
190 c->nb_threads = i;
191 slice_thread_uninit(c);
192 return AVERROR(ret);
193 }
194 }
195
196 slice_thread_park_workers(c);
197
198 return c->nb_threads;
199}
200
201int ff_graph_thread_init(AVFilterGraph *graph)
202{
203 int ret;
204
205#if HAVE_W32THREADS
206 w32thread_init();
207#endif
208
209 if (graph->nb_threads == 1) {
210 graph->thread_type = 0;
211 return 0;
212 }
213
214 graph->internal->thread = av_mallocz(sizeof(ThreadContext));
215 if (!graph->internal->thread)
216 return AVERROR(ENOMEM);
217
218 ret = thread_init_internal(graph->internal->thread, graph->nb_threads);
219 if (ret <= 1) {
220 av_freep(&graph->internal->thread);
221 graph->thread_type = 0;
222 graph->nb_threads = 1;
223 return (ret < 0) ? ret : 0;
224 }
225 graph->nb_threads = ret;
226
227 graph->internal->thread_execute = thread_execute;
228
229 return 0;
230}
231
232void ff_graph_thread_free(AVFilterGraph *graph)
233{
234 if (graph->internal->thread)
235 slice_thread_uninit(graph->internal->thread);
236 av_freep(&graph->internal->thread);
237}