w32pthreads: always use Vista+ API, drop XP support
[libav.git] / libavfilter / pthread.c
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129bb238 1/*
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2 * This file is part of Libav.
3 *
4 * Libav 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 * Libav 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 Libav; 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 * Libavfilter multithreading support
22 */
23
24#include "config.h"
25
26#include "libavutil/common.h"
27#include "libavutil/cpu.h"
28#include "libavutil/mem.h"
29
30#include "avfilter.h"
31#include "internal.h"
32#include "thread.h"
33
34#if HAVE_PTHREADS
35#include <pthread.h>
36#elif HAVE_W32THREADS
37#include "compat/w32pthreads.h"
38#endif
39
40typedef struct ThreadContext {
41 AVFilterGraph *graph;
42
43 int nb_threads;
44 pthread_t *workers;
0767bfd1 45 avfilter_action_func *func;
129bb238 46
41ed7ab4 47 /* per-execute parameters */
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48 AVFilterContext *ctx;
49 void *arg;
50 int *rets;
51 int nb_rets;
52 int nb_jobs;
53
54 pthread_cond_t last_job_cond;
55 pthread_cond_t current_job_cond;
56 pthread_mutex_t current_job_lock;
57 int current_job;
3511d4fc 58 unsigned int current_execute;
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59 int done;
60} ThreadContext;
61
62static void* attribute_align_arg worker(void *v)
63{
64 ThreadContext *c = v;
65 int our_job = c->nb_jobs;
66 int nb_threads = c->nb_threads;
3511d4fc 67 unsigned int last_execute = 0;
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68 int self_id;
69
70 pthread_mutex_lock(&c->current_job_lock);
71 self_id = c->current_job++;
72 for (;;) {
73 while (our_job >= c->nb_jobs) {
74 if (c->current_job == nb_threads + c->nb_jobs)
75 pthread_cond_signal(&c->last_job_cond);
76
3511d4fc 77 while (last_execute == c->current_execute && !c->done)
eb90a209 78 pthread_cond_wait(&c->current_job_cond, &c->current_job_lock);
3511d4fc 79 last_execute = c->current_execute;
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80 our_job = self_id;
81
82 if (c->done) {
83 pthread_mutex_unlock(&c->current_job_lock);
84 return NULL;
85 }
86 }
87 pthread_mutex_unlock(&c->current_job_lock);
88
89 c->rets[our_job % c->nb_rets] = c->func(c->ctx, c->arg, our_job, c->nb_jobs);
90
91 pthread_mutex_lock(&c->current_job_lock);
92 our_job = c->current_job++;
93 }
94}
95
96static void slice_thread_uninit(ThreadContext *c)
97{
98 int i;
99
100 pthread_mutex_lock(&c->current_job_lock);
101 c->done = 1;
102 pthread_cond_broadcast(&c->current_job_cond);
103 pthread_mutex_unlock(&c->current_job_lock);
104
105 for (i = 0; i < c->nb_threads; i++)
106 pthread_join(c->workers[i], NULL);
107
108 pthread_mutex_destroy(&c->current_job_lock);
109 pthread_cond_destroy(&c->current_job_cond);
110 pthread_cond_destroy(&c->last_job_cond);
111 av_freep(&c->workers);
112}
113
114static void slice_thread_park_workers(ThreadContext *c)
115{
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116 while (c->current_job != c->nb_threads + c->nb_jobs)
117 pthread_cond_wait(&c->last_job_cond, &c->current_job_lock);
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118 pthread_mutex_unlock(&c->current_job_lock);
119}
120
0767bfd1 121static int thread_execute(AVFilterContext *ctx, avfilter_action_func *func,
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122 void *arg, int *ret, int nb_jobs)
123{
124 ThreadContext *c = ctx->graph->internal->thread;
125 int dummy_ret;
126
127 if (nb_jobs <= 0)
128 return 0;
129
130 pthread_mutex_lock(&c->current_job_lock);
131
132 c->current_job = c->nb_threads;
133 c->nb_jobs = nb_jobs;
134 c->ctx = ctx;
135 c->arg = arg;
136 c->func = func;
137 if (ret) {
138 c->rets = ret;
139 c->nb_rets = nb_jobs;
140 } else {
141 c->rets = &dummy_ret;
142 c->nb_rets = 1;
143 }
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144 c->current_execute++;
145
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146 pthread_cond_broadcast(&c->current_job_cond);
147
148 slice_thread_park_workers(c);
149
150 return 0;
151}
152
50612484 153static int thread_init_internal(ThreadContext *c, int nb_threads)
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154{
155 int i, ret;
156
157 if (!nb_threads) {
158 int nb_cpus = av_cpu_count();
159 av_log(c->graph, AV_LOG_DEBUG, "Detected %d logical cores.\n", nb_cpus);
160 // use number of cores + 1 as thread count if there is more than one
161 if (nb_cpus > 1)
162 nb_threads = nb_cpus + 1;
163 else
164 nb_threads = 1;
165 }
166
167 if (nb_threads <= 1)
168 return 1;
169
170 c->nb_threads = nb_threads;
171 c->workers = av_mallocz(sizeof(*c->workers) * nb_threads);
172 if (!c->workers)
173 return AVERROR(ENOMEM);
174
175 c->current_job = 0;
176 c->nb_jobs = 0;
177 c->done = 0;
178
179 pthread_cond_init(&c->current_job_cond, NULL);
180 pthread_cond_init(&c->last_job_cond, NULL);
181
182 pthread_mutex_init(&c->current_job_lock, NULL);
183 pthread_mutex_lock(&c->current_job_lock);
184 for (i = 0; i < nb_threads; i++) {
185 ret = pthread_create(&c->workers[i], NULL, worker, c);
186 if (ret) {
187 pthread_mutex_unlock(&c->current_job_lock);
188 c->nb_threads = i;
189 slice_thread_uninit(c);
190 return AVERROR(ret);
191 }
192 }
193
194 slice_thread_park_workers(c);
195
196 return c->nb_threads;
197}
198
199int ff_graph_thread_init(AVFilterGraph *graph)
200{
201 int ret;
202
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203 if (graph->nb_threads == 1) {
204 graph->thread_type = 0;
205 return 0;
206 }
207
208 graph->internal->thread = av_mallocz(sizeof(ThreadContext));
209 if (!graph->internal->thread)
210 return AVERROR(ENOMEM);
211
50612484 212 ret = thread_init_internal(graph->internal->thread, graph->nb_threads);
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213 if (ret <= 1) {
214 av_freep(&graph->internal->thread);
215 graph->thread_type = 0;
216 graph->nb_threads = 1;
217 return (ret < 0) ? ret : 0;
218 }
219 graph->nb_threads = ret;
220
221 graph->internal->thread_execute = thread_execute;
222
223 return 0;
224}
225
226void ff_graph_thread_free(AVFilterGraph *graph)
227{
228 if (graph->internal->thread)
229 slice_thread_uninit(graph->internal->thread);
230 av_freep(&graph->internal->thread);
231}