| 1 | /* Multithreading primitives. |
| 2 | Copyright (C) 2005-2020 Free Software Foundation, Inc. |
| 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 |
| 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 <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; |