summaryrefslogtreecommitdiffstats
path: root/libavcodec/pthread.c
blob: 702adb533d4e86364f98a372d6b5349bc8ee3ec4 (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
/*
 * Copyright (c) 2004 Roman Shaposhnik.
 *
 * Many thanks to Steven M. Schultz for providing clever ideas and
 * to Michael Niedermayer <michaelni@gmx.at> for writing initial
 * implementation.
 *
 * 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 <pthread.h>

#include "avcodec.h"

typedef int (action_t)(AVCodecContext *c, void *arg);

typedef struct ThreadContext {
    pthread_t *workers;
    action_t *func;
    void **args;
    int *rets;
    int rets_count;
    int job_count;

    pthread_cond_t last_job_cond;
    pthread_cond_t current_job_cond;
    pthread_mutex_t current_job_lock;
    int current_job;
    int done;
} ThreadContext;

static void* attribute_align_arg worker(void *v)
{
    AVCodecContext *avctx = v;
    ThreadContext *c = avctx->thread_opaque;
    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);

            pthread_cond_wait(&c->current_job_cond, &c->current_job_lock);
            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(avctx, c->args[our_job]);

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

static av_always_inline void avcodec_thread_park_workers(ThreadContext *c, int thread_count)
{
    pthread_cond_wait(&c->last_job_cond, &c->current_job_lock);
    pthread_mutex_unlock(&c->current_job_lock);
}

void avcodec_thread_free(AVCodecContext *avctx)
{
    ThreadContext *c = avctx->thread_opaque;
    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->thread_opaque);
}

int avcodec_thread_execute(AVCodecContext *avctx, action_t* func, void **arg, int *ret, int job_count)
{
    ThreadContext *c= avctx->thread_opaque;
    int dummy_ret;

    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->args = arg;
    c->func = func;
    if (ret) {
        c->rets = ret;
        c->rets_count = job_count;
    } else {
        c->rets = &dummy_ret;
        c->rets_count = 1;
    }
    pthread_cond_broadcast(&c->current_job_cond);

    avcodec_thread_park_workers(c, avctx->thread_count);

    return 0;
}

int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
{
    int i;
    ThreadContext *c;

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

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

    avctx->thread_opaque = c;
    avctx->thread_count = thread_count;
    c->current_job = 0;
    c->job_count = 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);
           avcodec_thread_free(avctx);
           return -1;
        }
    }

    avcodec_thread_park_workers(c, thread_count);

    avctx->execute = avcodec_thread_execute;
    return 0;
}
OpenPOWER on IntegriCloud