1 /* Multithreading primitives.
2 Copyright (C) 2005-2022 Free Software Foundation, Inc.
3
4 This file is free software: you can redistribute it and/or modify
5 it under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 2.1 of the
7 License, or (at your option) any later version.
8
9 This file 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
12 GNU Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
16
17 /* Written by Bruno Haible <bruno@clisp.org>, 2005. */
18
19 #include <config.h>
20
21 /* ========================================================================= */
22
23 #if USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS
24
25 /* Use the POSIX threads library. */
26
27 # include <errno.h>
28 # include <pthread.h>
29 # include <stdlib.h>
30
31 # if PTHREAD_IN_USE_DETECTION_HARD
32
33 # if defined __FreeBSD__ || defined __DragonFly__ /* FreeBSD */
34
35 /* Test using pthread_key_create. */
36
37 int
glthread_in_use(void)38 glthread_in_use (void)
39 {
40 static int tested;
41 static int result; /* 1: linked with -lpthread, 0: only with libc */
42
43 if (!tested)
44 {
45 pthread_key_t key;
46 int err = pthread_key_create (&key, NULL);
47
48 if (err == ENOSYS)
49 result = 0;
50 else
51 {
52 result = 1;
53 if (err == 0)
54 pthread_key_delete (key);
55 }
56 tested = 1;
57 }
58 return result;
59 }
60
61 # else /* Solaris, HP-UX */
62
63 /* Test using pthread_create. */
64
65 /* The function to be executed by a dummy thread. */
66 static void *
dummy_thread_func(void * arg)67 dummy_thread_func (void *arg)
68 {
69 return arg;
70 }
71
72 int
glthread_in_use(void)73 glthread_in_use (void)
74 {
75 static int tested;
76 static int result; /* 1: linked with -lpthread, 0: only with libc */
77
78 if (!tested)
79 {
80 pthread_t thread;
81
82 if (pthread_create (&thread, NULL, dummy_thread_func, NULL) != 0)
83 /* Thread creation failed. */
84 result = 0;
85 else
86 {
87 /* Thread creation works. */
88 void *retval;
89 if (pthread_join (thread, &retval) != 0)
90 abort ();
91 result = 1;
92 }
93 tested = 1;
94 }
95 return result;
96 }
97
98 # endif
99
100 # endif
101
102 #endif
103
104 /* ========================================================================= */
105
106 /* This declaration is solely to ensure that after preprocessing
107 this file is never empty. */
108 typedef int dummy;
109