1 /*****************************************************************************
2  * threadpool.c: thread pooling
3  *****************************************************************************
4  * Copyright (C) 2010-2021 x264 project
5  *
6  * Authors: Steven Walters <kemuri9@gmail.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111, USA.
21  *
22  * This program is also available under a commercial proprietary license.
23  * For more information, contact us at licensing@x264.com.
24  *****************************************************************************/
25 
26 #include "common.h"
27 
28 typedef struct
29 {
30     void *(*func)(void *);
31     void *arg;
32     void *ret;
33 } x264_threadpool_job_t;
34 
35 struct x264_threadpool_t
36 {
37     volatile int   exit;
38     int            threads;
39     x264_pthread_t *thread_handle;
40     void           (*init_func)(void *);
41     void           *init_arg;
42 
43     /* requires a synchronized list structure and associated methods,
44        so use what is already implemented for frames */
45     x264_sync_frame_list_t uninit; /* list of jobs that are awaiting use */
46     x264_sync_frame_list_t run;    /* list of jobs that are queued for processing by the pool */
47     x264_sync_frame_list_t done;   /* list of jobs that have finished processing */
48 };
49 
threadpool_thread(x264_threadpool_t * pool)50 REALIGN_STACK static void *threadpool_thread( x264_threadpool_t *pool )
51 {
52     if( pool->init_func )
53         pool->init_func( pool->init_arg );
54 
55     while( !pool->exit )
56     {
57         x264_threadpool_job_t *job = NULL;
58         x264_pthread_mutex_lock( &pool->run.mutex );
59         while( !pool->exit && !pool->run.i_size )
60             x264_pthread_cond_wait( &pool->run.cv_fill, &pool->run.mutex );
61         if( pool->run.i_size )
62         {
63             job = (void*)x264_frame_shift( pool->run.list );
64             pool->run.i_size--;
65         }
66         x264_pthread_mutex_unlock( &pool->run.mutex );
67         if( !job )
68             continue;
69         job->ret = job->func( job->arg );
70         x264_sync_frame_list_push( &pool->done, (void*)job );
71     }
72     return NULL;
73 }
74 
x264_threadpool_init(x264_threadpool_t ** p_pool,int threads,void (* init_func)(void *),void * init_arg)75 int x264_threadpool_init( x264_threadpool_t **p_pool, int threads,
76                           void (*init_func)(void *), void *init_arg )
77 {
78     if( threads <= 0 )
79         return -1;
80 
81     if( x264_threading_init() < 0 )
82         return -1;
83 
84     x264_threadpool_t *pool;
85     CHECKED_MALLOCZERO( pool, sizeof(x264_threadpool_t) );
86     *p_pool = pool;
87 
88     pool->init_func = init_func;
89     pool->init_arg  = init_arg;
90     pool->threads   = threads;
91 
92     CHECKED_MALLOC( pool->thread_handle, pool->threads * sizeof(x264_pthread_t) );
93 
94     if( x264_sync_frame_list_init( &pool->uninit, pool->threads ) ||
95         x264_sync_frame_list_init( &pool->run, pool->threads ) ||
96         x264_sync_frame_list_init( &pool->done, pool->threads ) )
97         goto fail;
98 
99     for( int i = 0; i < pool->threads; i++ )
100     {
101        x264_threadpool_job_t *job;
102        CHECKED_MALLOC( job, sizeof(x264_threadpool_job_t) );
103        x264_sync_frame_list_push( &pool->uninit, (void*)job );
104     }
105     for( int i = 0; i < pool->threads; i++ )
106         if( x264_pthread_create( pool->thread_handle+i, NULL, (void*)threadpool_thread, pool ) )
107             goto fail;
108 
109     return 0;
110 fail:
111     return -1;
112 }
113 
x264_threadpool_run(x264_threadpool_t * pool,void * (* func)(void *),void * arg)114 void x264_threadpool_run( x264_threadpool_t *pool, void *(*func)(void *), void *arg )
115 {
116     x264_threadpool_job_t *job = (void*)x264_sync_frame_list_pop( &pool->uninit );
117     job->func = func;
118     job->arg  = arg;
119     x264_sync_frame_list_push( &pool->run, (void*)job );
120 }
121 
x264_threadpool_wait(x264_threadpool_t * pool,void * arg)122 void *x264_threadpool_wait( x264_threadpool_t *pool, void *arg )
123 {
124     x264_pthread_mutex_lock( &pool->done.mutex );
125     while( 1 )
126     {
127         for( int i = 0; i < pool->done.i_size; i++ )
128             if( ((x264_threadpool_job_t*)pool->done.list[i])->arg == arg )
129             {
130                 x264_threadpool_job_t *job = (void*)x264_frame_shift( pool->done.list+i );
131                 pool->done.i_size--;
132                 x264_pthread_mutex_unlock( &pool->done.mutex );
133 
134                 void *ret = job->ret;
135                 x264_sync_frame_list_push( &pool->uninit, (void*)job );
136                 return ret;
137             }
138 
139         x264_pthread_cond_wait( &pool->done.cv_fill, &pool->done.mutex );
140     }
141 }
142 
threadpool_list_delete(x264_sync_frame_list_t * slist)143 static void threadpool_list_delete( x264_sync_frame_list_t *slist )
144 {
145     for( int i = 0; slist->list[i]; i++ )
146     {
147         x264_free( slist->list[i] );
148         slist->list[i] = NULL;
149     }
150     x264_sync_frame_list_delete( slist );
151 }
152 
x264_threadpool_delete(x264_threadpool_t * pool)153 void x264_threadpool_delete( x264_threadpool_t *pool )
154 {
155     x264_pthread_mutex_lock( &pool->run.mutex );
156     pool->exit = 1;
157     x264_pthread_cond_broadcast( &pool->run.cv_fill );
158     x264_pthread_mutex_unlock( &pool->run.mutex );
159     for( int i = 0; i < pool->threads; i++ )
160         x264_pthread_join( pool->thread_handle[i], NULL );
161 
162     threadpool_list_delete( &pool->uninit );
163     threadpool_list_delete( &pool->run );
164     threadpool_list_delete( &pool->done );
165     x264_free( pool->thread_handle );
166     x264_free( pool );
167 }
168