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  Licensed to Accellera Systems Initiative Inc. (Accellera) under one or
  more contributor license agreements.  See the NOTICE file distributed
  with this work for additional information regarding copyright ownership.
  Accellera licenses this file to you under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with the
  License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
  implied.  See the License for the specific language governing
  permissions and limitations under the License.

 *****************************************************************************/
#ifndef TLM_UTILS_INSTANCE_SPECIFIC_EXTENSIONS_INT_H_INCLUDED_
#define TLM_UTILS_INSTANCE_SPECIFIC_EXTENSIONS_INT_H_INCLUDED_

#ifndef SC_BUILD // incluce full TLM, when not building the library
#include <tlm>
#else
#include "tlm_core/tlm_2/tlm_generic_payload/tlm_gp.h"
#endif // SC_BUILD

namespace tlm_utils {
class SC_API ispex_base;
class SC_API instance_specific_extension_accessor;
class SC_API instance_specific_extension_container;
class instance_specific_extension_carrier;
class instance_specific_extension_container_pool;
}

namespace tlm {
SC_API_TEMPLATE_DECL_ tlm_array<tlm_utils::ispex_base*>;
} // namespace tlm

namespace tlm_utils {

//The private extension base. Similar to normal extension base, but without clone and free
class SC_API ispex_base
{
    friend class tlm::tlm_array<ispex_base*>;
    void free() {} // needed for explicit tlm_array instantiation
public:
    virtual ~ispex_base() {}
protected:
    static unsigned int register_private_extension(const std::type_info&);
};

//this thing is basically a snippet of the generic_payload
// it contains all the extension specific code (the extension API so to speak)
// the differences are:
// - it calls back to its owner whenever a real (==non-NULL) extension gets set for the first time
// - it calls back to its owner whenever a living (==non-NULL) extension gets cleared
class SC_API instance_specific_extensions_per_accessor
{
public:
  typedef instance_specific_extension_container container_type;

  explicit
  instance_specific_extensions_per_accessor(container_type* container)
    : m_container(container)
  {}

  template <typename T> T* set_extension(T* ext)
  {
      return static_cast<T*>( set_extension(T::priv_id, ext) );
  }

  // non-templatized version with manual index:
  ispex_base* set_extension(unsigned int index, ispex_base* ext);

  // Check for an extension, ext will point to 0 if not present
  template <typename T> void get_extension(T*& ext) const
  {
      ext = static_cast<T*>(get_extension(T::priv_id));
  }
  // Non-templatized version:
   ispex_base* get_extension(unsigned int index) const;

  // Clear extension, the argument is needed to find the right index:
  template <typename T> void clear_extension(const T*)
  {
      clear_extension(T::priv_id);
  }

  // Non-templatized version with manual index
  void clear_extension(unsigned int index);

  // Make sure the extension array is large enough. Can be called once by
  // an initiator module (before issuing the first transaction) to make
  // sure that the extension array is of correct size. This is only needed
  // if the initiator cannot guarantee that the generic payload object is
  // allocated after C++ static construction time.
  void resize_extensions();

private:
  tlm::tlm_array<ispex_base*> m_extensions;
  container_type* m_container;

}; // class instance_specific_extensions_per_accessor

#if defined(_MSC_VER) && !defined(SC_WIN_DLL_WARN)
#pragma warning(push)
#pragma warning(disable: 4251) // DLL import for vector
#endif

//this thing contains the vector of extensions per accessor
//which can be really large so this one should be pool allocated
// therefore it keeps a use_count of itself to automatically free itself
// - to this end it provides callbacks to the extensions per accessor
//   to increment and decrement the use_count
class SC_API instance_specific_extension_container
{
  friend class instance_specific_extension_accessor;
  friend class instance_specific_extension_carrier;
  friend class instance_specific_extension_container_pool;
  friend class instance_specific_extensions_per_accessor;

  typedef void release_fn(instance_specific_extension_carrier*,void*);

  instance_specific_extension_container();
  ~instance_specific_extension_container();

  void resize();

  void inc_use_count();
  void dec_use_count();

  static instance_specific_extension_container* create();
  void attach_carrier(instance_specific_extension_carrier*, void* txn, release_fn*);

  instance_specific_extensions_per_accessor* get_accessor(unsigned int index);

  std::vector<instance_specific_extensions_per_accessor*> m_ispex_per_accessor;
  unsigned int use_count;
  void* m_txn;
  release_fn* m_release_fn;
  instance_specific_extension_carrier* m_carrier;
  instance_specific_extension_container* next; //for pooling

}; // class instance_specific_extension_container

#if defined(_MSC_VER) && !defined(SC_WIN_DLL_WARN)
#pragma warning(pop)
#endif

// ----------------------------------------------------------------------------

//This class 'hides' all the instance specific extension stuff from the user
// he instantiates one of those (e.g. instance_specific_extension_accessor extAcc;) and can then access
// the private extensions
//    extAcc(txn).extensionAPIFnCall()
//  where extensionAPIFnCall is set_extension, get_extension, clear_extension,...
class SC_API instance_specific_extension_accessor
{
public:
  instance_specific_extension_accessor();

  template<typename T> // implementation in instance_specific_extensions.h
  inline instance_specific_extensions_per_accessor& operator()(T& txn);

protected:
  template<typename T>
  static void release_carrier(instance_specific_extension_carrier*, void* txn);

  unsigned int m_index;
}; // class instance_specific_extension_accessor

} // namespace tlm_utils
#endif // TLM_UTILS_INSTANCE_SPECIFIC_EXTENSIONS_INT_H_INCLUDED_