3 * This file is part of FFmpeg.
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.
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.
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
22 * Libavfilter multithreading support
27 #include "libavutil/common.h"
28 #include "libavutil/cpu.h"
29 #include "libavutil/mem.h"
38 #include "compat/os2threads.h"
40 #include "compat/w32pthreads.h"
43 typedef struct ThreadContext {
48 avfilter_action_func *func;
50 /* per-execute perameters */
57 pthread_cond_t last_job_cond;
58 pthread_cond_t current_job_cond;
59 pthread_mutex_t current_job_lock;
61 unsigned int current_execute;
65 static void* attribute_align_arg worker(void *v)
68 int our_job = c->nb_jobs;
69 int nb_threads = c->nb_threads;
70 unsigned int last_execute = 0;
73 pthread_mutex_lock(&c->current_job_lock);
74 self_id = c->current_job++;
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);
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;
86 pthread_mutex_unlock(&c->current_job_lock);
90 pthread_mutex_unlock(&c->current_job_lock);
92 c->rets[our_job % c->nb_rets] = c->func(c->ctx, c->arg, our_job, c->nb_jobs);
94 pthread_mutex_lock(&c->current_job_lock);
95 our_job = c->current_job++;
99 static void slice_thread_uninit(ThreadContext *c)
103 pthread_mutex_lock(&c->current_job_lock);
105 pthread_cond_broadcast(&c->current_job_cond);
106 pthread_mutex_unlock(&c->current_job_lock);
108 for (i = 0; i < c->nb_threads; i++)
109 pthread_join(c->workers[i], NULL);
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);
117 static void slice_thread_park_workers(ThreadContext *c)
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);
124 static int thread_execute(AVFilterContext *ctx, avfilter_action_func *func,
125 void *arg, int *ret, int nb_jobs)
127 ThreadContext *c = ctx->graph->internal->thread;
133 pthread_mutex_lock(&c->current_job_lock);
135 c->current_job = c->nb_threads;
136 c->nb_jobs = nb_jobs;
142 c->nb_rets = nb_jobs;
144 c->rets = &dummy_ret;
147 c->current_execute++;
149 pthread_cond_broadcast(&c->current_job_cond);
151 slice_thread_park_workers(c);
156 static int thread_init_internal(ThreadContext *c, int nb_threads)
161 int nb_cpus = av_cpu_count();
162 // use number of cores + 1 as thread count if there is more than one
164 nb_threads = nb_cpus + 1;
172 c->nb_threads = nb_threads;
173 c->workers = av_mallocz_array(sizeof(*c->workers), nb_threads);
175 return AVERROR(ENOMEM);
181 pthread_cond_init(&c->current_job_cond, NULL);
182 pthread_cond_init(&c->last_job_cond, NULL);
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);
189 pthread_mutex_unlock(&c->current_job_lock);
191 slice_thread_uninit(c);
196 slice_thread_park_workers(c);
198 return c->nb_threads;
201 int ff_graph_thread_init(AVFilterGraph *graph)
209 if (graph->nb_threads == 1) {
210 graph->thread_type = 0;
214 graph->internal->thread = av_mallocz(sizeof(ThreadContext));
215 if (!graph->internal->thread)
216 return AVERROR(ENOMEM);
218 ret = thread_init_internal(graph->internal->thread, graph->nb_threads);
220 av_freep(&graph->internal->thread);
221 graph->thread_type = 0;
222 graph->nb_threads = 1;
223 return (ret < 0) ? ret : 0;
225 graph->nb_threads = ret;
227 graph->internal->thread_execute = thread_execute;
232 void ff_graph_thread_free(AVFilterGraph *graph)
234 if (graph->internal->thread)
235 slice_thread_uninit(graph->internal->thread);
236 av_freep(&graph->internal->thread);