1 /* Copyright (C) 2002-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <pthread.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <unistd.h>
22 #include <sys/file.h>
23
24
25 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
26
27 static int fd;
28
29
30 static void *
tf(void * arg)31 tf (void *arg)
32 {
33 if (flock (fd, LOCK_SH | LOCK_NB) != 0)
34 {
35 puts ("second flock failed");
36 exit (1);
37 }
38
39 pthread_mutex_unlock (&lock);
40
41 return NULL;
42 }
43
44
45 static int
do_test(void)46 do_test (void)
47 {
48 char tmp[] = "/tmp/tst-flock1-XXXXXX";
49
50 fd = mkstemp (tmp);
51 if (fd == -1)
52 {
53 puts ("mkstemp failed");
54 exit (1);
55 }
56
57 unlink (tmp);
58
59 write (fd, "foobar xyzzy", 12);
60
61 if (flock (fd, LOCK_EX | LOCK_NB) != 0)
62 {
63 puts ("first flock failed");
64 exit (1);
65 }
66
67 pthread_mutex_lock (&lock);
68
69 pthread_t th;
70 if (pthread_create (&th, NULL, tf, NULL) != 0)
71 {
72 puts ("pthread_create failed");
73 exit (1);
74 }
75
76 pthread_mutex_lock (&lock);
77
78 void *result;
79 if (pthread_join (th, &result) != 0)
80 {
81 puts ("pthread_join failed");
82 exit (1);
83 }
84
85 close (fd);
86
87 return result != NULL;
88 }
89
90 #define TEST_FUNCTION do_test ()
91 #include "../test-skeleton.c"
92