mingw-w64-libraries/winpthreads/tests/pthread_mutex/mutex4e.c

/*
 *      Pthreads-win32 - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999,2005 Pthreads-win32 contributors
 *      Copyright(C) 2026 mingw-w64 project
 *
 *      Contact Email: mingw-w64-public@lists.sourceforge.net
 *
 *      The current list of contributors is contained
 *      in the file CONTRIBUTORS included with the source
 *      code distribution. The list can also be seen at the
 *      following World Wide Web location:
 *      http://sources.redhat.com/pthreads-win32/contributors.html
 *
 *      This library is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU Lesser General Public
 *      License as published by the Free Software Foundation; either
 *      version 2 of the License, or (at your option) any later version.
 *
 *      This library is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *      Lesser General Public License for more details.
 *
 *      You should have received a copy of the GNU Lesser General Public
 *      License along with this library in the file COPYING.LIB;
 *      if not, write to the Free Software Foundation, Inc.,
 *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 *
 * --------------------------------------------------------------------------
 *
 * Thread A locks mutex - thread B tries to unlock.
 *
 * Depends on API functions:
 *  pthread_mutex_lock()
 *  pthread_mutex_trylock()
 *  pthread_mutex_unlock()
 */

#include "test.h"

static int wasHere = 0;

static pthread_mutex_t mutex1;

void *unlocker(void *arg)
{
  int expectedResult = (int) (size_t) arg;
  int h;

  wasHere++;
  h = pthread_mutex_unlock(&mutex1);
  printf("*** %d==%d\n\n", h, expectedResult);
  fflush(stdout);
  assert(h == expectedResult);
  wasHere++;

  return NULL;
}

int main(void)
{
  pthread_t t;
  pthread_mutexattr_t ma;

  assert(pthread_mutexattr_init(&ma) == 0);

  wasHere = 0;
  assert(pthread_mutexattr_settype(&ma, PTHREAD_MUTEX_ERRORCHECK) == 0);
  assert(pthread_mutex_init(&mutex1, &ma) == 0);
  assert(pthread_mutex_lock(&mutex1) == 0);
  assert(pthread_create(&t, NULL, unlocker, (void *) EPERM) == 0);
  assert(pthread_join(t, NULL) == 0);
  assert(pthread_mutex_unlock(&mutex1) == 0);
  assert(wasHere == 2);

  return 0;
}