1 /* C11 threads timed mutex tests.
2 Copyright (C) 2018-2022 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 <threads.h>
20 #include <stdio.h>
21 #include <unistd.h>
22
23 #include <support/check.h>
24
25 /* Shared mutex between child and parent. */
26 static mtx_t mutex;
27
28 /* Shared counter to check possible race conditions. */
29 static char shrd_counter;
30
31 /* Maximum amount of time waiting for mutex. */
32 static struct timespec wait_time;
33
34 /* Function to choose an action to do, depending on mtx_timedlock
35 return value. */
36 static inline void
choose_action(int action,char * thread_name)37 choose_action (int action, char* thread_name)
38 {
39 switch (action)
40 {
41 case thrd_success:
42 ++shrd_counter;
43
44 if (mtx_unlock (&mutex) != thrd_success)
45 FAIL_EXIT1 ("mtx_unlock failed");
46 break;
47
48 case thrd_timedout:
49 break;
50
51 case thrd_error:
52 FAIL_EXIT1 ("%s lock error", thread_name);
53 break;
54 }
55 }
56
57 static int
child_add(void * arg)58 child_add (void *arg)
59 {
60 char child_name[] = "child";
61
62 /* Try to lock mutex. */
63 choose_action (mtx_timedlock (&mutex, &wait_time), child_name);
64 thrd_exit (thrd_success);
65 }
66
67 static int
do_test(void)68 do_test (void)
69 {
70 thrd_t id;
71 char parent_name[] = "parent";
72
73 if (mtx_init (&mutex, mtx_timed) != thrd_success)
74 FAIL_EXIT1 ("mtx_init failed");
75
76 if (clock_gettime (CLOCK_REALTIME, &wait_time) != 0)
77 FAIL_EXIT1 ("clock_gettime failed");
78 /* Tiny amount of time, to assure that if any thread finds it busy.
79 It will receive thrd_timedout. */
80 wait_time.tv_nsec += 1;
81 if (wait_time.tv_nsec == 1000 * 1000 * 1000)
82 {
83 wait_time.tv_sec += 1;
84 wait_time.tv_nsec = 0;
85 }
86
87 if (thrd_create (&id, child_add, NULL) != thrd_success)
88 FAIL_EXIT1 ("thrd_create failed");
89
90 choose_action (mtx_timedlock (&mutex, &wait_time), parent_name);
91
92 if (thrd_join (id, NULL) != thrd_success)
93 FAIL_EXIT1 ("thrd_join failed");
94
95 if (shrd_counter != 2 && shrd_counter != 1)
96 FAIL_EXIT1 ("shrd_counter != {1,2} (%d)", shrd_counter);
97
98 mtx_destroy (&mutex);
99
100 return 0;
101 }
102
103 #include <support/test-driver.c>
104