Semaphore.h++

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/* ---------------------------------------------------------------------------
   commonc++ - A C++ Common Class Library
   Copyright (C) 2005-2012  Mark A Lindner

   This file is part of commonc++.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   ---------------------------------------------------------------------------
*/

#ifndef __ccxx_Semaphore_hxx
#define __ccxx_Semaphore_hxx

#include <commonc++/Common.h++>
#include <commonc++/Lock.h++>
#include <commonc++/Permissions.h++>
#include <commonc++/String.h++>
#include <commonc++/SystemException.h++>

#ifdef CCXX_OS_POSIX
#include <fcntl.h>
#include <semaphore.h>
#endif

namespace ccxx {

class COMMONCPP_API Semaphore : public Lock
{
  public:

  Semaphore(const String &name, uint_t value = 1,
            const Permissions& perm = Permissions::USER_READ_WRITE);

  ~Semaphore() throw();

  void init() throw(SystemException);

  bool wait() throw();

  inline void lock() throw()
  { wait(); }

  bool tryWait() throw();

  bool signal() throw();

  inline void unlock() throw()
  { signal(); }

  int getValue() const throw();

  inline String getName() const
  { return(_name); }

  private:

  String _name;
  uint_t _value;
  Permissions _perm;
  bool _initialized;

#ifdef CCXX_OS_WINDOWS
  HANDLE _sem;
#else
  sem_t *_sem;
#endif
};

}; // namespace ccxx

#endif // __ccxx_Semaphore_hxx