1 /* Test pthread_once.
2    Copyright (C) 2000-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library;  if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #define _GNU_SOURCE
20 
21 #include <pthread.h>
22 #include <assert.h>
23 #include <error.h>
24 #include <errno.h>
25 
26 #define THREADS 10
27 
28 pthread_once_t inc_var_once = PTHREAD_ONCE_INIT;
29 int var;
30 
31 void
inc_var(void)32 inc_var (void)
33 {
34   var++;
35 }
36 
37 void *
thr(void * arg)38 thr (void *arg)
39 {
40   int i;
41 
42   for (i = 0; i < 500; i++)
43     pthread_once (&inc_var_once, inc_var);
44 
45   return 0;
46 }
47 
48 int
main(int argc,char ** argv)49 main (int argc, char **argv)
50 {
51   error_t err;
52   int i;
53   pthread_t tid[THREADS];
54 
55   for (i = 0; i < THREADS; i++)
56     {
57       err = pthread_create (&tid[i], 0, thr, 0);
58       if (err)
59 	error (1, err, "pthread_create (%d)", i);
60     }
61 
62   assert (thr (0) == 0);
63 
64   for (i = 0; i < THREADS; i++)
65     {
66       void *ret;
67 
68       err = pthread_join (tid[i], &ret);
69       if (err)
70 	error (1, err, "pthread_join");
71 
72       assert (ret == 0);
73     }
74 
75   assert (var == 1);
76 
77   return 0;
78 }
79