DataObjectLocked.hpp

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/***************************************************************************
  tag: Peter Soetens  Mon Jan 19 14:11:26 CET 2004  DataObjectLocked.hpp

                        DataObjectLocked.hpp -  description
                           -------------------
    begin                : Mon January 19 2004
    copyright            : (C) 2004 Peter Soetens
    email                : peter.soetens@mech.kuleuven.ac.be

 ***************************************************************************
 *   This library is free software; you can redistribute it and/or         *
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 *   version 2 of the License.                                             *
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#ifndef CORELIB_DATAOBJECT_LOCKED_HPP
#define CORELIB_DATAOBJECT_LOCKED_HPP


#include "../os/MutexLock.hpp"
#include "DataObjectInterface.hpp"

namespace RTT
{ namespace base {

    template<class T>
    class DataObjectLocked
        : public DataObjectInterface<T>
    {
        typedef typename DataObjectInterface<T>::value_t value_t;
        typedef typename DataObjectInterface<T>::reference_t reference_t;
        typedef typename DataObjectInterface<T>::param_t param_t;

        mutable os::Mutex lock;

        value_t data;

        mutable FlowStatus status;
        bool initialized;

    public:
        DataObjectLocked()
            : data(), status(NoData), initialized(false) {}

        DataObjectLocked( param_t initial_value )
            : data(initial_value), status(NoData), initialized(true) {}

        typedef T DataType;

        virtual FlowStatus Get( reference_t pull, bool copy_old_data = true ) const {
            os::MutexLock locker(lock);
            FlowStatus result = status;
            if (status == NewData) {
                pull = data;
                status = OldData;
            } else if ((status == OldData) && copy_old_data) {
                pull = data;
            }
            return result;
        }

        virtual value_t Get() const {
            DataType cache = DataType();
            Get(cache);
            return cache;
        }

        virtual bool Set( param_t push ) {
            os::MutexLock locker(lock);
            data = push;
            status = NewData;
            return true;
        }

        virtual bool data_sample( param_t sample, bool reset ) {
            os::MutexLock locker(lock);
            if (!initialized || reset) {
                data = sample;
                status = NoData;
                initialized = true;
                return true;
            } else {
                return initialized;
            }
        }

        virtual value_t data_sample() const {
            os::MutexLock locker(lock);
            return data;
        }

        virtual void clear() {
            os::MutexLock locker(lock);
            status = NoData;
        }
    };
}}

#endif