src/systemc/ext/tlm_utils/instance_specific_extensions_int.h

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  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
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#ifndef __SYSTEMC_EXT_TLM_UTILS_INSTANCE_SPECIFIC_EXTENSIONS_INT_H__
#define __SYSTEMC_EXT_TLM_UTILS_INSTANCE_SPECIFIC_EXTENSIONS_INT_H__

#include <vector>

#include "../tlm_core/2/generic_payload/array.hh"

namespace tlm_utils
{

class ispex_base;
class instance_specific_extension_accessor;
class instance_specific_extension_container;
class instance_specific_extension_carrier;
class instance_specific_extension_container_pool;

} // namespace tlm_utils

namespace tlm
{

extern template class 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 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 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 be nullptr 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;
};

// 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 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.
};

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

// This class 'hides' all the instance specific extension stuff from the user.
// They 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 instance_specific_extension_accessor
{
  public:
    instance_specific_extension_accessor();

    // Implementation in instance_specific_extensions.h
    template <typename T>
    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;
};

} // namespace tlm_utils

#endif /* __SYSTEMC_EXT_TLM_UTILS_INSTANCE_SPECIFIC_EXTENSIONS_INT_H__ */