spl/threading/Semaphore.h

/* Original source attribution */
/* ---------------------------------------------------------------------------
   commonc++ - A C++ Common Class Library
   Copyright (C) 2005-2009  Mark A Lindner

   Ported to SPL from 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 _semaphore_h
#define _semaphore_h

#include <spl/types.h>
#include <spl/Exception.h>
#include <spl/Memory.h>
#include <spl/threading/Mutex.h>
#include <spl/io/Permissions.h>
#include <spl/String.h>
#include <spl/RefCountPtr.h>

#ifndef _WINDOWS
#include <fcntl.h>
#include <semaphore.h>
#endif

class Semaphore;
typedef RefCountPtr<Semaphore> SemaphorePtr;
typedef WeakReference<Semaphore, SemaphorePtr> SemaphoreRef;

REGISTER_TYPEOF( 472, SemaphorePtr );
REGISTER_TYPEOF( 475, SemaphoreRef );

class Semaphore : public IMemoryValidate
{
private:
        String _name;

#ifdef _WINDOWS
        HANDLE _sem;
#else
        sem_t *_sem;
#endif

public:

        Semaphore
        (
                const String& name, 
                uint32 value = 1,
                const Permissions& perm = Permissions::USER_READ_WRITE
        );

        ~Semaphore();

        void Lock();

        bool TryWait();

        void Unlock();

        int GetValue() const;

        inline const String& GetName() const
        { 
                return(_name); 
        }

#ifdef DEBUG
        virtual void ValidateMem() const;
        virtual void CheckMem() const;
#endif
};

REGISTER_TYPEOF( 476, Semaphore );

#endif