105436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Multithreading primitives.
205436638acc7c010349a69c3395f1a57c642dc62Ying Wang   Copyright (C) 2005-2012 Free Software Foundation, Inc.
305436638acc7c010349a69c3395f1a57c642dc62Ying Wang
405436638acc7c010349a69c3395f1a57c642dc62Ying Wang   This program is free software; you can redistribute it and/or modify
505436638acc7c010349a69c3395f1a57c642dc62Ying Wang   it under the terms of the GNU General Public License as published by
605436638acc7c010349a69c3395f1a57c642dc62Ying Wang   the Free Software Foundation; either version 3, or (at your option)
705436638acc7c010349a69c3395f1a57c642dc62Ying Wang   any later version.
805436638acc7c010349a69c3395f1a57c642dc62Ying Wang
905436638acc7c010349a69c3395f1a57c642dc62Ying Wang   This program is distributed in the hope that it will be useful,
1005436638acc7c010349a69c3395f1a57c642dc62Ying Wang   but WITHOUT ANY WARRANTY; without even the implied warranty of
1105436638acc7c010349a69c3395f1a57c642dc62Ying Wang   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
1205436638acc7c010349a69c3395f1a57c642dc62Ying Wang   GNU General Public License for more details.
1305436638acc7c010349a69c3395f1a57c642dc62Ying Wang
1405436638acc7c010349a69c3395f1a57c642dc62Ying Wang   You should have received a copy of the GNU General Public License
1505436638acc7c010349a69c3395f1a57c642dc62Ying Wang   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
1605436638acc7c010349a69c3395f1a57c642dc62Ying Wang
1705436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Written by Bruno Haible <bruno@clisp.org>, 2005.  */
1805436638acc7c010349a69c3395f1a57c642dc62Ying Wang
1905436638acc7c010349a69c3395f1a57c642dc62Ying Wang#include <config.h>
2005436638acc7c010349a69c3395f1a57c642dc62Ying Wang
2105436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* ========================================================================= */
2205436638acc7c010349a69c3395f1a57c642dc62Ying Wang
2305436638acc7c010349a69c3395f1a57c642dc62Ying Wang#if USE_POSIX_THREADS
2405436638acc7c010349a69c3395f1a57c642dc62Ying Wang
2505436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* Use the POSIX threads library.  */
2605436638acc7c010349a69c3395f1a57c642dc62Ying Wang
2705436638acc7c010349a69c3395f1a57c642dc62Ying Wang# include <pthread.h>
2805436638acc7c010349a69c3395f1a57c642dc62Ying Wang# include <stdlib.h>
2905436638acc7c010349a69c3395f1a57c642dc62Ying Wang
3005436638acc7c010349a69c3395f1a57c642dc62Ying Wang# if PTHREAD_IN_USE_DETECTION_HARD
3105436638acc7c010349a69c3395f1a57c642dc62Ying Wang
3205436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* The function to be executed by a dummy thread.  */
3305436638acc7c010349a69c3395f1a57c642dc62Ying Wangstatic void *
3405436638acc7c010349a69c3395f1a57c642dc62Ying Wangdummy_thread_func (void *arg)
3505436638acc7c010349a69c3395f1a57c642dc62Ying Wang{
3605436638acc7c010349a69c3395f1a57c642dc62Ying Wang  return arg;
3705436638acc7c010349a69c3395f1a57c642dc62Ying Wang}
3805436638acc7c010349a69c3395f1a57c642dc62Ying Wang
3905436638acc7c010349a69c3395f1a57c642dc62Ying Wangint
4005436638acc7c010349a69c3395f1a57c642dc62Ying Wangglthread_in_use (void)
4105436638acc7c010349a69c3395f1a57c642dc62Ying Wang{
4205436638acc7c010349a69c3395f1a57c642dc62Ying Wang  static int tested;
4305436638acc7c010349a69c3395f1a57c642dc62Ying Wang  static int result; /* 1: linked with -lpthread, 0: only with libc */
4405436638acc7c010349a69c3395f1a57c642dc62Ying Wang
4505436638acc7c010349a69c3395f1a57c642dc62Ying Wang  if (!tested)
4605436638acc7c010349a69c3395f1a57c642dc62Ying Wang    {
4705436638acc7c010349a69c3395f1a57c642dc62Ying Wang      pthread_t thread;
4805436638acc7c010349a69c3395f1a57c642dc62Ying Wang
4905436638acc7c010349a69c3395f1a57c642dc62Ying Wang      if (pthread_create (&thread, NULL, dummy_thread_func, NULL) != 0)
5005436638acc7c010349a69c3395f1a57c642dc62Ying Wang        /* Thread creation failed.  */
5105436638acc7c010349a69c3395f1a57c642dc62Ying Wang        result = 0;
5205436638acc7c010349a69c3395f1a57c642dc62Ying Wang      else
5305436638acc7c010349a69c3395f1a57c642dc62Ying Wang        {
5405436638acc7c010349a69c3395f1a57c642dc62Ying Wang          /* Thread creation works.  */
5505436638acc7c010349a69c3395f1a57c642dc62Ying Wang          void *retval;
5605436638acc7c010349a69c3395f1a57c642dc62Ying Wang          if (pthread_join (thread, &retval) != 0)
5705436638acc7c010349a69c3395f1a57c642dc62Ying Wang            abort ();
5805436638acc7c010349a69c3395f1a57c642dc62Ying Wang          result = 1;
5905436638acc7c010349a69c3395f1a57c642dc62Ying Wang        }
6005436638acc7c010349a69c3395f1a57c642dc62Ying Wang      tested = 1;
6105436638acc7c010349a69c3395f1a57c642dc62Ying Wang    }
6205436638acc7c010349a69c3395f1a57c642dc62Ying Wang  return result;
6305436638acc7c010349a69c3395f1a57c642dc62Ying Wang}
6405436638acc7c010349a69c3395f1a57c642dc62Ying Wang
6505436638acc7c010349a69c3395f1a57c642dc62Ying Wang# endif
6605436638acc7c010349a69c3395f1a57c642dc62Ying Wang
6705436638acc7c010349a69c3395f1a57c642dc62Ying Wang#endif
6805436638acc7c010349a69c3395f1a57c642dc62Ying Wang
6905436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* ========================================================================= */
7005436638acc7c010349a69c3395f1a57c642dc62Ying Wang
7105436638acc7c010349a69c3395f1a57c642dc62Ying Wang/* This declaration is solely to ensure that after preprocessing
7205436638acc7c010349a69c3395f1a57c642dc62Ying Wang   this file is never empty.  */
7305436638acc7c010349a69c3395f1a57c642dc62Ying Wangtypedef int dummy;
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