1 /* Verify that pthread_create does not deadlock when ctors take locks.
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 #include <stdio.h>
20 #include <support/xdlfcn.h>
21 #include <support/xthread.h>
22
23 /*
24 Check if ctor and pthread_create deadlocks in
25
26 thread 1: dlopen -> ctor -> lock(user_lock)
27 thread 2: lock(user_lock) -> pthread_create
28
29 or in
30
31 thread 1: dlclose -> dtor -> lock(user_lock)
32 thread 2: lock(user_lock) -> pthread_create
33 */
34
35 static pthread_barrier_t bar_ctor;
36 static pthread_barrier_t bar_ctor_finish;
37 static pthread_barrier_t bar_dtor;
38 static pthread_mutex_t user_lock = PTHREAD_MUTEX_INITIALIZER;
39
40 void
ctor(void)41 ctor (void)
42 {
43 xpthread_barrier_wait (&bar_ctor);
44 dprintf (1, "thread 1: in ctor: started.\n");
45 xpthread_mutex_lock (&user_lock);
46 dprintf (1, "thread 1: in ctor: locked user_lock.\n");
47 xpthread_mutex_unlock (&user_lock);
48 dprintf (1, "thread 1: in ctor: unlocked user_lock.\n");
49 dprintf (1, "thread 1: in ctor: done.\n");
50 xpthread_barrier_wait (&bar_ctor_finish);
51 }
52
53 void
dtor(void)54 dtor (void)
55 {
56 xpthread_barrier_wait (&bar_dtor);
57 dprintf (1, "thread 1: in dtor: started.\n");
58 xpthread_mutex_lock (&user_lock);
59 dprintf (1, "thread 1: in dtor: locked user_lock.\n");
60 xpthread_mutex_unlock (&user_lock);
61 dprintf (1, "thread 1: in dtor: unlocked user_lock.\n");
62 dprintf (1, "thread 1: in dtor: done.\n");
63 }
64
65 static void *
thread3(void * a)66 thread3 (void *a)
67 {
68 dprintf (1, "thread 3: started.\n");
69 dprintf (1, "thread 3: done.\n");
70 return 0;
71 }
72
73 static void *
thread2(void * a)74 thread2 (void *a)
75 {
76 pthread_t t3;
77 dprintf (1, "thread 2: started.\n");
78
79 xpthread_mutex_lock (&user_lock);
80 dprintf (1, "thread 2: locked user_lock.\n");
81 xpthread_barrier_wait (&bar_ctor);
82 t3 = xpthread_create (0, thread3, 0);
83 xpthread_mutex_unlock (&user_lock);
84 dprintf (1, "thread 2: unlocked user_lock.\n");
85 xpthread_join (t3);
86 xpthread_barrier_wait (&bar_ctor_finish);
87
88 xpthread_mutex_lock (&user_lock);
89 dprintf (1, "thread 2: locked user_lock.\n");
90 xpthread_barrier_wait (&bar_dtor);
91 t3 = xpthread_create (0, thread3, 0);
92 xpthread_mutex_unlock (&user_lock);
93 dprintf (1, "thread 2: unlocked user_lock.\n");
94 xpthread_join (t3);
95
96 dprintf (1, "thread 2: done.\n");
97 return 0;
98 }
99
100 static void
thread1(void)101 thread1 (void)
102 {
103 dprintf (1, "thread 1: started.\n");
104 xpthread_barrier_init (&bar_ctor, NULL, 2);
105 xpthread_barrier_init (&bar_ctor_finish, NULL, 2);
106 xpthread_barrier_init (&bar_dtor, NULL, 2);
107 pthread_t t2 = xpthread_create (0, thread2, 0);
108 void *p = xdlopen ("tst-create1mod.so", RTLD_NOW | RTLD_GLOBAL);
109 dprintf (1, "thread 1: dlopen done.\n");
110 xdlclose (p);
111 dprintf (1, "thread 1: dlclose done.\n");
112 xpthread_join (t2);
113 dprintf (1, "thread 1: done.\n");
114 }
115
116 static int
do_test(void)117 do_test (void)
118 {
119 thread1 ();
120 return 0;
121 }
122
123 #include <support/test-driver.c>
124