1/* Support file for atexit/exit, etc. race tests (BZ #27749).
2 Copyright (C) 2021-2022 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/* The atexit/exit, at_quick_exit/quick_exit, __cxa_atexit/exit, etc.
20 exhibited data race while calling destructors.
21
22 This test registers destructors from the background thread, and checks that
23 the same destructor is not called more than once. */
24
25#include <stdatomic.h>
26#include <stdio.h>
27#include <stdlib.h>
28#include <support/check.h>
29#include <support/xthread.h>
30#include <support/xunistd.h>
31#include <sys/wait.h>
32#include <unistd.h>
33
34static atomic_int registered;
35static atomic_int todo = 100000;
36
37static void
38atexit_cb (void *arg)
39{
40 atomic_fetch_sub (&registered, 1);
41 static void *prev;
42 if (arg == prev)
43 FAIL_EXIT1 ("%s: %p\n", __func__, arg);
44 prev = arg;
45
46 while (atomic_load (&todo) > 0 && atomic_load (&registered) < 100)
47 ;
48}
49
50int __cxa_atexit (void (*func) (void *), void *arg, void *d);
51
52static void *
53thread_func (void *arg)
54{
55 void *cb_arg = NULL;
56 while (atomic_load (&todo) > 0)
57 {
58 if (atomic_load (&registered) < 10000)
59 {
60 int n = 10;
61 for (int i = 0; i < n; ++i)
62 __cxa_atexit (func: &atexit_cb, arg: ++cb_arg, d: 0);
63 atomic_fetch_add (&registered, n);
64 atomic_fetch_sub (&todo, n);
65 }
66 }
67
68 return NULL;
69}
70
71_Noreturn static void
72test_and_exit (void)
73{
74 pthread_attr_t attr;
75
76 xpthread_attr_init (attr: &attr);
77 xpthread_attr_setdetachstate (attr: &attr, detachstate: 1);
78
79 xpthread_create (attr: &attr, thread_func, NULL);
80 xpthread_attr_destroy (attr: &attr);
81
82 while (atomic_load (&registered) == 0)
83 ;
84 exit (0);
85}
86
87static int
88do_test (void)
89{
90 for (int i = 0; i < 20; ++i)
91 {
92 for (int i = 0; i < 10; ++i)
93 if (xfork () == 0)
94 test_and_exit ();
95
96 for (int i = 0; i < 10; ++i)
97 {
98 int status;
99 xwaitpid (0, status: &status, flags: 0);
100 if (!WIFEXITED (status))
101 FAIL_EXIT1 ("Failed iterations %d", i);
102 TEST_COMPARE (WEXITSTATUS (status), 0);
103 }
104 }
105
106 return 0;
107}
108
109#define TEST_FUNCTION do_test
110#include <support/test-driver.c>
111

source code of glibc/stdlib/test-cxa_atexit-race2.c