summaryrefslogtreecommitdiff
path: root/libavcodec/pthread_slice.c
blob: d7c73f08840fc61372bc2fb8ca02b09b6ebcf359 (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
/*
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * Slice multithreading support functions
 * @see doc/multithreading.txt
 */

#include "config.h"

#if HAVE_PTHREADS
#include <pthread.h>
#elif HAVE_W32THREADS
#include "compat/w32pthreads.h"
#endif

#include "avcodec.h"
#include "internal.h"
#include "pthread_internal.h"
#include "thread.h"

#include "libavutil/common.h"
#include "libavutil/cpu.h"
#include "libavutil/mem.h"

typedef int (action_func)(AVCodecContext *c, void *arg);
typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);

typedef struct SliceThreadContext {
    pthread_t *workers;
    action_func *func;
    action_func2 *func2;
    void *args;
    int *rets;
    int rets_count;
    int job_count;
    int job_size;

    pthread_cond_t last_job_cond;
    pthread_cond_t current_job_cond;
    pthread_mutex_t current_job_lock;
    unsigned current_execute;
    int current_job;
    int done;
} SliceThreadContext;

static void* attribute_align_arg worker(void *v)
{
    AVCodecContext *avctx = v;
    SliceThreadContext *c = avctx->internal->thread_ctx;
    unsigned last_execute = 0;
    int our_job = c->job_count;
    int thread_count = avctx->thread_count;
    int self_id;

    pthread_mutex_lock(&c->current_job_lock);
    self_id = c->current_job++;
    for (;;){
        while (our_job >= c->job_count) {
            if (c->current_job == thread_count + c->job_count)
                pthread_cond_signal(&c->last_job_cond);

            while (last_execute == c->current_execute && !c->done)
                pthread_cond_wait(&c->current_job_cond, &c->current_job_lock);
            last_execute = c->current_execute;
            our_job = self_id;

            if (c->done) {
                pthread_mutex_unlock(&c->current_job_lock);
                return NULL;
            }
        }
        pthread_mutex_unlock(&c->current_job_lock);

        c->rets[our_job%c->rets_count] = c->func ? c->func(avctx, (char*)c->args + our_job*c->job_size):
                                                   c->func2(avctx, c->args, our_job, self_id);

        pthread_mutex_lock(&c->current_job_lock);
        our_job = c->current_job++;
    }
}

void ff_slice_thread_free(AVCodecContext *avctx)
{
    SliceThreadContext *c = avctx->internal->thread_ctx;
    int i;

    pthread_mutex_lock(&c->current_job_lock);
    c->done = 1;
    pthread_cond_broadcast(&c->current_job_cond);
    pthread_mutex_unlock(&c->current_job_lock);

    for (i=0; i<avctx->thread_count; i++)
         pthread_join(c->workers[i], NULL);

    pthread_mutex_destroy(&c->current_job_lock);
    pthread_cond_destroy(&c->current_job_cond);
    pthread_cond_destroy(&c->last_job_cond);
    av_free(c->workers);
    av_freep(&avctx->internal->thread_ctx);
}

static av_always_inline void thread_park_workers(SliceThreadContext *c, int thread_count)
{
    while (c->current_job != thread_count + c->job_count)
        pthread_cond_wait(&c->last_job_cond, &c->current_job_lock);
    pthread_mutex_unlock(&c->current_job_lock);
}

static int thread_execute(AVCodecContext *avctx, action_func* func, void *arg, int *ret, int job_count, int job_size)
{
    SliceThreadContext *c = avctx->internal->thread_ctx;
    int dummy_ret;

    if (!(avctx->active_thread_type&FF_THREAD_SLICE) || avctx->thread_count <= 1)
        return avcodec_default_execute(avctx, func, arg, ret, job_count, job_size);

    if (job_count <= 0)
        return 0;

    pthread_mutex_lock(&c->current_job_lock);

    c->current_job = avctx->thread_count;
    c->job_count = job_count;
    c->job_size = job_size;
    c->args = arg;
    c->func = func;
    if (ret) {
        c->rets = ret;
        c->rets_count = job_count;
    } else {
        c->rets = &dummy_ret;
        c->rets_count = 1;
    }
    c->current_execute++;
    pthread_cond_broadcast(&c->current_job_cond);

    thread_park_workers(c, avctx->thread_count);

    return 0;
}

static int thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
{
    SliceThreadContext *c = avctx->internal->thread_ctx;
    c->func2 = func2;
    return thread_execute(avctx, NULL, arg, ret, job_count, 0);
}

int ff_slice_thread_init(AVCodecContext *avctx)
{
    int i;
    SliceThreadContext *c;
    int thread_count = avctx->thread_count;

#if HAVE_W32THREADS
    w32thread_init();
#endif

    if (!thread_count) {
        int nb_cpus = av_cpu_count();
        av_log(avctx, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);
        // use number of cores + 1 as thread count if there is more than one
        if (nb_cpus > 1)
            thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
        else
            thread_count = avctx->thread_count = 1;
    }

    if (thread_count <= 1) {
        avctx->active_thread_type = 0;
        return 0;
    }

    c = av_mallocz(sizeof(SliceThreadContext));
    if (!c)
        return -1;

    c->workers = av_mallocz(sizeof(pthread_t)*thread_count);
    if (!c->workers) {
        av_free(c);
        return -1;
    }

    avctx->internal->thread_ctx = c;
    c->current_job = 0;
    c->job_count = 0;
    c->job_size = 0;
    c->done = 0;
    pthread_cond_init(&c->current_job_cond, NULL);
    pthread_cond_init(&c->last_job_cond, NULL);
    pthread_mutex_init(&c->current_job_lock, NULL);
    pthread_mutex_lock(&c->current_job_lock);
    for (i=0; i<thread_count; i++) {
        if(pthread_create(&c->workers[i], NULL, worker, avctx)) {
           avctx->thread_count = i;
           pthread_mutex_unlock(&c->current_job_lock);
           ff_thread_free(avctx);
           return -1;
        }
    }

    thread_park_workers(c, thread_count);

    avctx->execute = thread_execute;
    avctx->execute2 = thread_execute2;
    return 0;
}