Semaphore.h++

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/* ---------------------------------------------------------------------------
   commonc++ - A C++ Common Class Library
   Copyright (C) 2005-2014  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();

  void init();

  bool wait();

  inline void lock()
  { wait(); }

  bool tryWait();

  bool signal();

  inline void unlock()
  { signal(); }

  int getValue() const;

  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