shared_message.h

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/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Copyright(c) 2020 John Wellbelove
 
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#ifndef ETL_SHARED_MESSAGE_INCLUDED
#define ETL_SHARED_MESSAGE_INCLUDED
 
#include "platform.h"
#include "utility.h"
#include "reference_counted_message.h"
#include "ireference_counted_message_pool.h"
#include "message.h"
#include "type_traits.h"
#include "static_assert.h"
 
//*****************************************************************************
//*****************************************************************************
namespace etl
{
  class shared_message
  {
  public:
 
    //*************************************************************************
    //*************************************************************************
    template <typename TPool, typename TMessage>
    shared_message(TPool& owner, const TMessage& message)
    {
      ETL_STATIC_ASSERT((etl::is_base_of<etl::ireference_counted_message_pool, TPool>::value), "TPool not derived from etl::ireference_counted_message_pool");
      ETL_STATIC_ASSERT((etl::is_base_of<etl::imessage, TMessage>::value), "TMessage not derived from etl::imessage");
 
      p_rcmessage = owner.allocate(message);
      
      if (p_rcmessage != ETL_NULLPTR)
      {
        p_rcmessage->get_reference_counter().set_reference_count(1U);
      }
    }
 
    //*************************************************************************
    //*************************************************************************
    shared_message(etl::ireference_counted_message& rcm)
    {
      p_rcmessage = &rcm;
 
      p_rcmessage->get_reference_counter().set_reference_count(1U);
    }
 
    //*************************************************************************
    //*************************************************************************
    shared_message(const etl::shared_message& other)
      : p_rcmessage(other.p_rcmessage)
    {
      p_rcmessage->get_reference_counter().increment_reference_count();
    }
 
#if ETL_USING_CPP11
    //*************************************************************************
    //*************************************************************************
    shared_message(etl::shared_message&& other) ETL_NOEXCEPT
      : p_rcmessage(etl::move(other.p_rcmessage))
    {
      other.p_rcmessage = ETL_NULLPTR;
    }
#endif
 
    //*************************************************************************
    //*************************************************************************
    shared_message& operator =(const etl::shared_message& other)
    {
      if (&other != this)
      {
        // Deal with the current message.
        if (p_rcmessage->get_reference_counter().decrement_reference_count() == 0U)
        {
          p_rcmessage->release();
        }
 
        // Copy over the new one.
        p_rcmessage = other.p_rcmessage;
        p_rcmessage->get_reference_counter().increment_reference_count();
       }
 
      return *this;
    }
 
#if ETL_USING_CPP11
    //*************************************************************************
    //*************************************************************************
    shared_message& operator =(etl::shared_message&& other) ETL_NOEXCEPT
    {
      if (&other != this)
      {
        // Deal with the current message.
        if (p_rcmessage->get_reference_counter().decrement_reference_count() == 0U)
        {
          p_rcmessage->release();
        }
 
        // Move over the new one.
        p_rcmessage = etl::move(other.p_rcmessage);
        other.p_rcmessage = ETL_NULLPTR;
      }
 
      return *this;
    }
#endif
 
    //*************************************************************************
    //*************************************************************************
    ~shared_message()
    {
      if ((p_rcmessage != ETL_NULLPTR) &&
          (p_rcmessage->get_reference_counter().decrement_reference_count() == 0U))
      {       
        p_rcmessage->release();
      }
    }
 
    //*************************************************************************
    //***********************************************************************
    ETL_NODISCARD etl::imessage& get_message()
    {
      return p_rcmessage->get_message();
    }
 
    //*************************************************************************
    //*************************************************************************
    ETL_NODISCARD const etl::imessage& get_message() const
    {
      return p_rcmessage->get_message();
    }
 
    //*************************************************************************
    //*************************************************************************
    ETL_NODISCARD uint32_t get_reference_count() const
    {
      return p_rcmessage->get_reference_counter().get_reference_count();
    }
 
    //*************************************************************************
    //*************************************************************************
    ETL_NODISCARD bool is_valid() const
    {
      return p_rcmessage != ETL_NULLPTR;
    }
 
  private:
 
    shared_message() ETL_DELETE;
 
    etl::ireference_counted_message* p_rcmessage; 
  };
}
 
#endif