summaryrefslogtreecommitdiffstats
path: root/media/ffvpx/libavutil/slicethread.c
blob: 115b0997369921bfb986c3af3f9f02f96bcf77f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/*
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <stdatomic.h>
#include "cpu.h"
#include "internal.h"
#include "slicethread.h"
#include "mem.h"
#include "thread.h"
#include "avassert.h"

#define MAX_AUTO_THREADS 16

#if HAVE_PTHREADS || HAVE_W32THREADS || HAVE_OS2THREADS

typedef struct WorkerContext {
    AVSliceThread   *ctx;
    pthread_mutex_t mutex;
    pthread_cond_t  cond;
    pthread_t       thread;
    int             done;
} WorkerContext;

struct AVSliceThread {
    WorkerContext   *workers;
    int             nb_threads;
    int             nb_active_threads;
    int             nb_jobs;

    atomic_uint     first_job;
    atomic_uint     current_job;
    pthread_mutex_t done_mutex;
    pthread_cond_t  done_cond;
    int             done;
    int             finished;

    void            *priv;
    void            (*worker_func)(void *priv, int jobnr, int threadnr, int nb_jobs, int nb_threads);
    void            (*main_func)(void *priv);
};

static int run_jobs(AVSliceThread *ctx)
{
    unsigned nb_jobs    = ctx->nb_jobs;
    unsigned nb_active_threads = ctx->nb_active_threads;
    unsigned first_job    = atomic_fetch_add_explicit(&ctx->first_job, 1, memory_order_acq_rel);
    unsigned current_job  = first_job;

    do {
        ctx->worker_func(ctx->priv, current_job, first_job, nb_jobs, nb_active_threads);
    } while ((current_job = atomic_fetch_add_explicit(&ctx->current_job, 1, memory_order_acq_rel)) < nb_jobs);

    return current_job == nb_jobs + nb_active_threads - 1;
}

static void *attribute_align_arg thread_worker(void *v)
{
    WorkerContext *w = v;
    AVSliceThread *ctx = w->ctx;

    pthread_mutex_lock(&w->mutex);
    pthread_cond_signal(&w->cond);

    while (1) {
        w->done = 1;
        while (w->done)
            pthread_cond_wait(&w->cond, &w->mutex);

        if (ctx->finished) {
            pthread_mutex_unlock(&w->mutex);
            return NULL;
        }

        if (run_jobs(ctx)) {
            pthread_mutex_lock(&ctx->done_mutex);
            ctx->done = 1;
            pthread_cond_signal(&ctx->done_cond);
            pthread_mutex_unlock(&ctx->done_mutex);
        }
    }
}

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)
{
    AVSliceThread *ctx;
    int nb_workers, i;

    av_assert0(nb_threads >= 0);
    if (!nb_threads) {
        int nb_cpus = av_cpu_count();
        if (nb_cpus > 1)
            nb_threads = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
        else
            nb_threads = 1;
    }

    nb_workers = nb_threads;
    if (!main_func)
        nb_workers--;

    *pctx = ctx = av_mallocz(sizeof(*ctx));
    if (!ctx)
        return AVERROR(ENOMEM);

    if (nb_workers && !(ctx->workers = av_calloc(nb_workers, sizeof(*ctx->workers)))) {
        av_freep(pctx);
        return AVERROR(ENOMEM);
    }

    ctx->priv        = priv;
    ctx->worker_func = worker_func;
    ctx->main_func   = main_func;
    ctx->nb_threads  = nb_threads;
    ctx->nb_active_threads = 0;
    ctx->nb_jobs     = 0;
    ctx->finished    = 0;

    atomic_init(&ctx->first_job, 0);
    atomic_init(&ctx->current_job, 0);
    pthread_mutex_init(&ctx->done_mutex, NULL);
    pthread_cond_init(&ctx->done_cond, NULL);
    ctx->done        = 0;

    for (i = 0; i < nb_workers; i++) {
        WorkerContext *w = &ctx->workers[i];
        int ret;
        w->ctx = ctx;
        pthread_mutex_init(&w->mutex, NULL);
        pthread_cond_init(&w->cond, NULL);
        pthread_mutex_lock(&w->mutex);
        w->done = 0;

        if (ret = pthread_create(&w->thread, NULL, thread_worker, w)) {
            ctx->nb_threads = main_func ? i : i + 1;
            pthread_mutex_unlock(&w->mutex);
            pthread_cond_destroy(&w->cond);
            pthread_mutex_destroy(&w->mutex);
            avpriv_slicethread_free(pctx);
            return AVERROR(ret);
        }

        while (!w->done)
            pthread_cond_wait(&w->cond, &w->mutex);
        pthread_mutex_unlock(&w->mutex);
    }

    return nb_threads;
}

void avpriv_slicethread_execute(AVSliceThread *ctx, int nb_jobs, int execute_main)
{
    int nb_workers, i, is_last = 0;

    av_assert0(nb_jobs > 0);
    ctx->nb_jobs           = nb_jobs;
    ctx->nb_active_threads = FFMIN(nb_jobs, ctx->nb_threads);
    atomic_store_explicit(&ctx->first_job, 0, memory_order_relaxed);
    atomic_store_explicit(&ctx->current_job, ctx->nb_active_threads, memory_order_relaxed);
    nb_workers             = ctx->nb_active_threads;
    if (!ctx->main_func || !execute_main)
        nb_workers--;

    for (i = 0; i < nb_workers; i++) {
        WorkerContext *w = &ctx->workers[i];
        pthread_mutex_lock(&w->mutex);
        w->done = 0;
        pthread_cond_signal(&w->cond);
        pthread_mutex_unlock(&w->mutex);
    }

    if (ctx->main_func && execute_main)
        ctx->main_func(ctx->priv);
    else
        is_last = run_jobs(ctx);

    if (!is_last) {
        pthread_mutex_lock(&ctx->done_mutex);
        while (!ctx->done)
            pthread_cond_wait(&ctx->done_cond, &ctx->done_mutex);
        ctx->done = 0;
        pthread_mutex_unlock(&ctx->done_mutex);
    }
}

void avpriv_slicethread_free(AVSliceThread **pctx)
{
    AVSliceThread *ctx;
    int nb_workers, i;

    if (!pctx || !*pctx)
        return;

    ctx = *pctx;
    nb_workers = ctx->nb_threads;
    if (!ctx->main_func)
        nb_workers--;

    ctx->finished = 1;
    for (i = 0; i < nb_workers; i++) {
        WorkerContext *w = &ctx->workers[i];
        pthread_mutex_lock(&w->mutex);
        w->done = 0;
        pthread_cond_signal(&w->cond);
        pthread_mutex_unlock(&w->mutex);
    }

    for (i = 0; i < nb_workers; i++) {
        WorkerContext *w = &ctx->workers[i];
        pthread_join(w->thread, NULL);
        pthread_cond_destroy(&w->cond);
        pthread_mutex_destroy(&w->mutex);
    }

    pthread_cond_destroy(&ctx->done_cond);
    pthread_mutex_destroy(&ctx->done_mutex);
    av_freep(&ctx->workers);
    av_freep(pctx);
}

#else /* HAVE_PTHREADS || HAVE_W32THREADS || HAVE_OS32THREADS */

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)
{
    *pctx = NULL;
    return AVERROR(ENOSYS);
}

void avpriv_slicethread_execute(AVSliceThread *ctx, int nb_jobs, int execute_main)
{
    av_assert0(0);
}

void avpriv_slicethread_free(AVSliceThread **pctx)
{
    av_assert0(!pctx || !*pctx);
}

#endif /* HAVE_PTHREADS || HAVE_W32THREADS || HAVE_OS32THREADS */