1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
/* Test for exit/dlclose race (Bug 22180).
Copyright (C) 2017-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
/* This file must be run from within a directory called "stdlib". */
/* This test verifies that when dlopen in one thread races against exit
in another thread, we don't call registered destructor twice.
Expected result:
second
first
... clean termination
*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <semaphore.h>
#include <support/check.h>
#include <support/xdlfcn.h>
#include <support/xthread.h>
/* Semaphore to ensure we have a happens-before between the first function
starting and exit being called. */
sem_t order1;
/* Semaphore to ensure we have a happens-before between the second function
starting and the first function returning. */
sem_t order2;
void *
exit_thread (void *arg)
{
/* Wait for the dlclose to start... */
sem_wait (&order1);
/* Then try to run the exit sequence which should call all
__cxa_atexit registered functions and in parallel with
the executing dlclose(). */
exit (0);
}
void
last (void)
{
/* Let dlclose thread proceed. */
sem_post (&order2);
}
int
main (void)
{
int value;
void *dso;
pthread_t thread;
atexit (last);
dso = xdlopen ("$ORIGIN/test-dlclose-exit-race-helper.so",
RTLD_NOW|RTLD_GLOBAL);
if ((value = pthread_create (&thread, NULL, exit_thread, NULL)) != 0)
{
/* If pthread_create fails, then exit() is called in the main
thread instead of a second thread, so the semaphore post that
would have happened in 'last' gets blocked behind the call to
first() - which is waiting on the semaphore, and thus
hangs. */
sem_post (&order2);
errno = value;
FAIL_EXIT1 ("pthread_create: %m");
}
xdlclose (dso);
xpthread_join (thread);
FAIL_EXIT1 ("Did not terminate via exit(0) in exit_thread() as expected.");
}
|
