FFmpeg
cpu_init.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 /*
20  * This test program tests whether the one-time initialization in
21  * av_get_cpu_flags() has data races.
22  */
23 
24 #include <stdio.h>
25 #include <string.h>
26 
27 #include "libavutil/cpu.h"
28 #include "libavutil/thread.h"
29 
30 static void *thread_main(void *arg)
31 {
32  int *flags = arg;
33 
35  return NULL;
36 }
37 
38 int main(void)
39 {
40  int cpu_flags1;
41  int cpu_flags2;
42  int ret;
43  pthread_t thread1;
44  pthread_t thread2;
45 
46  if ((ret = pthread_create(&thread1, NULL, thread_main, &cpu_flags1))) {
47  fprintf(stderr, "pthread_create failed: %s.\n", strerror(ret));
48  return 1;
49  }
50  if ((ret = pthread_create(&thread2, NULL, thread_main, &cpu_flags2))) {
51  fprintf(stderr, "pthread_create failed: %s.\n", strerror(ret));
52  return 1;
53  }
54  pthread_join(thread1, NULL);
55  pthread_join(thread2, NULL);
56 
57  if (cpu_flags1 < 0)
58  return 2;
59  if (cpu_flags2 < 0)
60  return 2;
61  if (cpu_flags1 != cpu_flags2)
62  return 3;
63 
64  return 0;
65 }
pthread_join
static av_always_inline int pthread_join(pthread_t thread, void **value_ptr)
Definition: os2threads.h:94
thread.h
av_get_cpu_flags
int av_get_cpu_flags(void)
Return the flags which specify extensions supported by the CPU.
Definition: cpu.c:107
thread_main
static void * thread_main(void *arg)
Definition: cpu_init.c:30
main
int main(void)
Definition: cpu_init.c:38
arg
const char * arg
Definition: jacosubdec.c:67
pthread_create
static av_always_inline int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg)
Definition: os2threads.h:80
NULL
#define NULL
Definition: coverity.c:32
cpu.h
pthread_t
Definition: os2threads.h:44
ret
ret
Definition: filter_design.txt:187
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:482