1 /* Create threads from multiple threads in parallel.
2 Copyright 2007-2024 Free Software Foundation, Inc.
3
4 This file is part of GDB.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18
19 #include <pthread.h>
20 #include <stdio.h>
21 #include <limits.h>
22
23 #define NUM_CREATE 1
24 #define NUM_THREAD 8
25
26 void *
thread_function(void * arg)27 thread_function (void *arg)
28 {
29 int x = * (int *) arg;
30
31 printf ("Thread <%d> executing\n", x);
32
33 return NULL;
34 }
35
36 void *
create_function(void * arg)37 create_function (void *arg)
38 {
39 pthread_attr_t attr;
40 pthread_t threads[NUM_THREAD];
41 int args[NUM_THREAD];
42 size_t stacksize;
43 int i = * (int *) arg;
44 int j;
45
46 pthread_attr_init (&attr); /* set breakpoint 1 here. */
47 pthread_attr_getstacksize (&attr, &stacksize);
48 pthread_attr_setstacksize (&attr, 2 * stacksize);
49
50 /* Create a ton of quick-executing threads, then wait for them to
51 complete. */
52 for (j = 0; j < NUM_THREAD; ++j)
53 {
54 args[j] = i * 1000 + j;
55 pthread_create (&threads[j], &attr, thread_function, &args[j]);
56 }
57
58 for (j = 0; j < NUM_THREAD; ++j)
59 pthread_join (threads[j], NULL);
60
61 pthread_attr_destroy (&attr);
62
63 return NULL;
64 }
65
66 int
main(int argc,char ** argv)67 main (int argc, char **argv)
68 {
69 pthread_attr_t attr;
70 pthread_t threads[NUM_CREATE];
71 int args[NUM_CREATE];
72 size_t stacksize;
73 int n, i;
74
75 pthread_attr_init (&attr);
76 pthread_attr_getstacksize (&attr, &stacksize);
77 pthread_attr_setstacksize (&attr, 2 * stacksize);
78
79 for (n = 0; n < 100; ++n)
80 {
81 for (i = 0; i < NUM_CREATE; i++)
82 {
83 args[i] = i;
84 pthread_create (&threads[i], &attr, create_function, &args[i]);
85 }
86
87 create_function (&i);
88 for (i = 0; i < NUM_CREATE; i++)
89 pthread_join (threads[i], NULL);
90 }
91
92 pthread_attr_destroy (&attr);
93
94 return 0;
95 }
96