/*
 * tryentercs.c
 *
 *
 * --------------------------------------------------------------------------
 *
 *      Pthreads-win32 - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999,2005 Pthreads-win32 contributors
 * 
 *      Contact Email: rpj@callisto.canberra.edu.au
 * 
 *      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.,
 *      51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 *
 * --------------------------------------------------------------------------
 *
 * See if we have the TryEnterCriticalSection function.
 * Does not use any part of pthreads.
 */

#include <windows.h>
#include <process.h>
#include <stdio.h>

/*
 * Function pointer to TryEnterCriticalSection if it exists
 * - otherwise NULL
 */
BOOL (WINAPI *_try_enter_critical_section)(LPCRITICAL_SECTION) =
NULL;

/*
 * Handle to kernel32.dll
 */
static HINSTANCE _h_kernel32;


int
main()
{
  CRITICAL_SECTION cs;

  SetLastError(0);

  printf("Last Error [main enter] %ld\n", (long) GetLastError());

  /*
   * Load KERNEL32 and try to get address of TryEnterCriticalSection
   */
  _h_kernel32 = LoadLibrary(TEXT("KERNEL32.DLL"));
  _try_enter_critical_section =
        (BOOL (PT_STDCALL *)(LPCRITICAL_SECTION))
        GetProcAddress(_h_kernel32,
                         (LPCSTR) "TryEnterCriticalSection");

  if (_try_enter_critical_section != NULL)
    {
      InitializeCriticalSection(&cs);

      SetLastError(0);

      if ((*_try_enter_critical_section)(&cs) != 0)
        {
          LeaveCriticalSection(&cs);
        }
	else
	  {
	    printf("Last Error [try enter] %ld\n", (long) GetLastError());

	    _try_enter_critical_section = NULL;
	  }
      DeleteCriticalSection(&cs);
    }

  (void) FreeLibrary(_h_kernel32);

  printf("This system %s TryEnterCriticalSection.\n",
         (_try_enter_critical_section == NULL) ? "DOES NOT SUPPORT" : "SUPPORTS");
  printf("POSIX Mutexes will be based on Win32 %s.\n",
         (_try_enter_critical_section == NULL) ? "Mutexes" : "Critical Sections");

  return(0);
}

