LockedQueue.hpp

/***************************************************************************
  tag: Peter Soetens  Thu Oct 22 11:59:08 CEST 2009  LockedQueue.hpp

                        LockedQueue.hpp -  description
                           -------------------
    begin                : Thu October 22 2009
    copyright            : (C) 2009 Peter Soetens
    email                : peter@thesourcworks.com

 ***************************************************************************
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU General Public                   *
 *   License as published by the Free Software Foundation;                 *
 *   version 2 of the License.                                             *
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 *   software library without restriction.  Specifically, if other files   *
 *   instantiate templates or use macros or inline functions from this     *
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 *   produce an executable, this file does not by itself cause the         *
 *   resulting executable to be covered by the GNU General Public          *
 *   License.  This exception does not however invalidate any other        *
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 *   Public License.                                                       *
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 ***************************************************************************/


#ifndef ORO_LOCKED_QUEUE_HPP
#define ORO_LOCKED_QUEUE_HPP

#include <deque>
#include "../os/Mutex.hpp"
#include "../os/MutexLock.hpp"

namespace RTT
{ namespace internal {

    template< class T>
    class LockedQueue
    {
    public:
        typedef T value_t;
    private:
        typedef std::deque<value_t> BufferType;
        typedef typename BufferType::iterator Iterator;
        typedef typename BufferType::const_iterator CIterator;
        mutable os::Mutex lock;
        BufferType data;

        unsigned int cap;
    public:
        typedef unsigned int size_type;

        LockedQueue(unsigned int lsize)
            : cap(lsize)
        {
            data.resize(lsize);
            data.resize(0);
        }

        ~LockedQueue() {
        }

        size_type capacity() const
        {
            return cap;
        }

        size_type size() const
        {
            os::MutexLock locker(lock);
            return data.size();
        }

        bool isEmpty() const
        {
            os::MutexLock locker(lock);
            return data.empty();
        }

        bool isFull() const
        {
            os::MutexLock locker(lock);
            return data.size() ==  cap;
        }

        void clear()
        {
            os::MutexLock locker(lock);
            data.clear();
        }

        bool enqueue(const T& value)
        {
            {
                os::MutexLock locker(lock);
                if (cap == data.size() )
                    return false;
                data.push_back(value);
            }
            return true;
        }

        bool dequeue( T& result )
        {
            {
                os::MutexLock locker(lock);
                if ( data.empty() )
                    return false;
                result = data.front();
                data.pop_front();
            }
            return true;
        }

        value_t front() const
        {
            os::MutexLock locker(lock);
            value_t item = value_t();
            if ( !data.empty() )
                item = data.front();
            return item;
        }

        value_t back() const
        {
            os::MutexLock locker(lock);
            value_t item = value_t();
            if ( !data.empty() )
                item = data.back();
            return item;
        }

    };

}}

#endif