1 /* Helper program for testing the pthread_mutex_t pretty printer.
2
3 Copyright (C) 2016-2023 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library 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 GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20 /* Keep the calls to the pthread_* functions on separate lines to make it easy
21 to advance through the program using the gdb 'next' command. */
22
23 #include <stdlib.h>
24 #include <errno.h>
25 #include <pthread.h>
26
27 #define PASS 0
28 #define FAIL 1
29
30 static int test_status_destroyed (pthread_mutex_t *mutex);
31 static int test_status_no_robust (pthread_mutex_t *mutex,
32 pthread_mutexattr_t *attr);
33 static int test_status_robust (pthread_mutex_t *mutex,
34 pthread_mutexattr_t *attr);
35 static int test_locking_state_robust (pthread_mutex_t *mutex);
36 static void *thread_func (void *arg);
37 static int test_recursive_locks (pthread_mutex_t *mutex,
38 pthread_mutexattr_t *attr);
39
40 int
41 main (void)
42 {
43 pthread_mutex_t mutex;
44 pthread_mutexattr_t attr;
45 int result = FAIL;
46
47 if (pthread_mutexattr_init (&attr) == 0
48 && test_status_destroyed (&mutex) == PASS
49 && test_status_no_robust (&mutex, &attr) == PASS
50 && test_status_robust (&mutex, &attr) == PASS
51 && test_recursive_locks (&mutex, &attr) == PASS)
52 result = PASS;
53 /* Else, one of the pthread_mutex* functions failed. */
54
55 return result;
56 }
57
58 /* Initializes MUTEX, then destroys it. */
59 static int
60 test_status_destroyed (pthread_mutex_t *mutex)
61 {
62 int result = FAIL;
63
64 if (pthread_mutex_init (mutex, NULL) == 0
65 && pthread_mutex_destroy (mutex) == 0)
66 result = PASS; /* Test status (destroyed). */
67
68 return result;
69 }
70
71 /* Tests locking of non-robust mutexes. */
72 static int
73 test_status_no_robust (pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
74 {
75 int result = FAIL;
76
77 if (pthread_mutexattr_setrobust (attr, PTHREAD_MUTEX_STALLED) == 0
78 && pthread_mutex_init (mutex, attr) == 0
79 && pthread_mutex_lock (mutex) == 0 /* Test status (non-robust). */
80 && pthread_mutex_unlock (mutex) == 0
81 && pthread_mutex_destroy (mutex) == 0)
82 result = PASS;
83
84 return result;
85 }
86
87 /* Tests locking of robust mutexes. */
88 static int
89 test_status_robust (pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
90 {
91 int result = FAIL;
92
93 if (pthread_mutexattr_setrobust (attr, PTHREAD_MUTEX_ROBUST) == 0
94 && pthread_mutex_init (mutex, attr) == 0
95 && test_locking_state_robust (mutex) == PASS /* Test status (robust). */
96 && pthread_mutex_destroy (mutex) == 0)
97 result = PASS;
98
99 return result;
100 }
101
102 /* Tests locking and state corruption of robust mutexes. We'll mark it as
103 inconsistent, then not recoverable. */
104 static int
105 test_locking_state_robust (pthread_mutex_t *mutex)
106 {
107 int result = FAIL;
108 pthread_t thread;
109
110 if (pthread_create (&thread, NULL, thread_func, mutex) == 0 /* Create. */
111 && pthread_join (thread, NULL) == 0
112 && pthread_mutex_lock (mutex) == EOWNERDEAD /* Test locking (robust). */
113 && pthread_mutex_unlock (mutex) == 0)
114 result = PASS;
115
116 return result;
117 }
118
119 /* Function to be called by the child thread when testing robust mutexes. */
120 static void *
121 thread_func (void *arg)
122 {
123 pthread_mutex_t *mutex = (pthread_mutex_t *)arg;
124
125 if (pthread_mutex_lock (mutex) != 0) /* Thread function. */
126 exit (FAIL);
127
128 /* Thread terminates without unlocking the mutex, thus marking it as
129 inconsistent. */
130 return NULL;
131 }
132
133 /* Tests locking the mutex multiple times in a row. */
134 static int
135 test_recursive_locks (pthread_mutex_t *mutex, pthread_mutexattr_t *attr)
136 {
137 int result = FAIL;
138
139 if (pthread_mutexattr_settype (attr, PTHREAD_MUTEX_RECURSIVE) == 0
140 && pthread_mutex_init (mutex, attr) == 0
141 && pthread_mutex_lock (mutex) == 0
142 && pthread_mutex_lock (mutex) == 0
143 && pthread_mutex_lock (mutex) == 0 /* Test recursive locks. */
144 && pthread_mutex_unlock (mutex) == 0
145 && pthread_mutex_unlock (mutex) == 0
146 && pthread_mutex_unlock (mutex) == 0
147 && pthread_mutex_destroy (mutex) == 0)
148 result = PASS;
149
150 return result;
151 }