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5abebf3c | 1 | /* Multithreading primitives. |
5df4cba6 | 2 | Copyright (C) 2005-2020 Free Software Foundation, Inc. |
5abebf3c CB |
3 | |
4 | This program is free software; you can redistribute it and/or modify | |
5 | it under the terms of the GNU General Public License as published by | |
6 | the Free Software Foundation; either version 3, or (at your option) | |
7 | any later version. | |
8 | ||
9 | This program 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 General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
c0c3707f | 15 | along with this program; if not, see <https://www.gnu.org/licenses/>. */ |
5abebf3c CB |
16 | |
17 | /* Written by Bruno Haible <bruno@clisp.org>, 2005. */ | |
18 | ||
19 | #include <config.h> | |
20 | ||
21 | /* ========================================================================= */ | |
22 | ||
c0c3707f | 23 | #if USE_POSIX_THREADS || USE_ISOC_AND_POSIX_THREADS |
5abebf3c CB |
24 | |
25 | /* Use the POSIX threads library. */ | |
26 | ||
27 | # include <pthread.h> | |
28 | # include <stdlib.h> | |
29 | ||
30 | # if PTHREAD_IN_USE_DETECTION_HARD | |
31 | ||
32 | /* The function to be executed by a dummy thread. */ | |
33 | static void * | |
34 | dummy_thread_func (void *arg) | |
35 | { | |
36 | return arg; | |
37 | } | |
38 | ||
39 | int | |
40 | glthread_in_use (void) | |
41 | { | |
42 | static int tested; | |
43 | static int result; /* 1: linked with -lpthread, 0: only with libc */ | |
44 | ||
45 | if (!tested) | |
46 | { | |
47 | pthread_t thread; | |
48 | ||
49 | if (pthread_create (&thread, NULL, dummy_thread_func, NULL) != 0) | |
50 | /* Thread creation failed. */ | |
51 | result = 0; | |
52 | else | |
53 | { | |
54 | /* Thread creation works. */ | |
55 | void *retval; | |
56 | if (pthread_join (thread, &retval) != 0) | |
57 | abort (); | |
58 | result = 1; | |
59 | } | |
60 | tested = 1; | |
61 | } | |
62 | return result; | |
63 | } | |
64 | ||
65 | # endif | |
66 | ||
67 | #endif | |
68 | ||
69 | /* ========================================================================= */ | |
70 | ||
71 | /* This declaration is solely to ensure that after preprocessing | |
72 | this file is never empty. */ | |
73 | typedef int dummy; |