第3月第13天 cpp模版 Iterator模式 proactor

1.模版除了传参，还可以自动创建。而传指针只是传参而已。

template <class TYPE, class FUNCTOR, class ACE_LOCK, typename TIME_POLICY = ACE_Default_Time_Policy>
class ACE_Timer_List_T : public ACE_Timer_Queue_T<TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY>
{
public:
  /// Type of iterator
  typedef ACE_Timer_List_Iterator_T<TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY> Iterator;

  /// Iterator is a friend
  friend class ACE_Timer_List_Iterator_T<TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY>;

  typedef ACE_Timer_Node_T<TYPE> Node;
  /// Type inherited from
  typedef ACE_Timer_Queue_T<TYPE, FUNCTOR, ACE_LOCK, TIME_POLICY> Base_Timer_Queue;
  typedef ACE_Free_List<Node> FreeList;

  // = Initialization and termination methods.
  /**
   * Default constructor. @a upcall_functor is the instance of the
   * FUNCTOR to be used by the list. If @a upcall_functor is 0, a
   * default FUNCTOR will be created.  @a freelist is the freelist of
   * timer nodes.  If 0, then a default freelist will be created.
   */
  ACE_Timer_List_T (FUNCTOR* upcall_functor = 0, FreeList* freelist = 0,
                    TIME_POLICY const & time_policy = TIME_POLICY());

template<typename TYPE, typename FUNCTOR>
class ACE_Timer_Queue_Upcall_Base
  : public ACE_Abstract_Timer_Queue<TYPE>
  , private ACE_Copy_Disabled
{
public:
  // Constructor
  explicit ACE_Timer_Queue_Upcall_Base(FUNCTOR * upcall_functor = 0);

  /// Destructor
  virtual ~ACE_Timer_Queue_Upcall_Base (void);

  /// Accessor to the upcall functor
  FUNCTOR & upcall_functor (void);

protected:
  /// Upcall functor
  FUNCTOR *upcall_functor_;

  /// To delete or not to delete is the question?
  bool const delete_upcall_functor_;
};


template <class TYPE, class FUNCTOR> ACE_INLINE
ACE_Timer_Queue_Upcall_Base<TYPE, FUNCTOR>::ACE_Timer_Queue_Upcall_Base (FUNCTOR * upcall_functor)
  : ACE_Abstract_Timer_Queue<TYPE>()
  , ACE_Copy_Disabled()
  , upcall_functor_(upcall_functor)
  , delete_upcall_functor_ (upcall_functor == 0)
{
  ACE_TRACE ("ACE_Timer_Queue_Upcall_Base::ACE_Timer_Queue_Upcall_Base");

  if (upcall_functor != 0)
    {
      return;
    }

  ACE_NEW (upcall_functor_, FUNCTOR);
}

2.Iterator模式

template <class TYPE>
class ACE_Timer_Queue_Iterator_T
{
public:
  // = Initialization and termination methods.
  /// Constructor.
  ACE_Timer_Queue_Iterator_T (void);

  /// Destructor.
  virtual ~ACE_Timer_Queue_Iterator_T (void);

  /// Positions the iterator at the earliest node in the Timer Queue
  virtual void first (void) = 0;

  /// Positions the iterator at the next node in the Timer Queue
  virtual void next (void) = 0;

  /// Returns true when there are no more nodes in the sequence
  virtual bool isdone (void) const = 0;

  /// Returns the node at the current position in the sequence
  virtual ACE_Timer_Node_T<TYPE> *item (void) = 0;
};

实现  ACE_Timer_Hash_T, ACE_Timer_Heap_T , ACE_Timer_List_T, ACE_Timer_Wheel_T

http://blog.csdn.net/u010700335/article/details/41214839

http://blogs.readthedocs.io/zh_CN/latest/Timer_mgr.html

3.proactor

1)

proactor关联了很多异步操作。Asynch_IO里的异步操作会调用proactor->create_asynch 。比如：ACE_Asynch_Accept::open  =>  proactor->create_asynch_accept ()  => ACE_WIN32_Asynch_Accept

ACE_Asynch_Read_Stream::open  => proactor->create_asynch_read_stream ()  =>  ACE_WIN32_Asynch_Read_Stream。

Receiver调用this->rs_.read (*mb, mb->size ()- 1)  => ACE_Asynch_Read_Stream::read  => ACE_WIN32_Asynch_Read_Stream::read。

有数据时proactor会调用  ACE_WIN32_Asynch_Read_Stream_Result::complete  => handler->handle_read_stream (result)就回到Receiver。

ACE_Asynch_Read_Stream_Impl *
ACE_Proactor::create_asynch_read_stream (void)
{
  return this->implementation ()->create_asynch_read_stream ();
}

ACE_Asynch_Write_Stream_Impl *
ACE_Proactor::create_asynch_write_stream (void)
{
  return this->implementation ()->create_asynch_write_stream ();
}

ACE_Asynch_Read_Dgram_Impl *
ACE_Proactor::create_asynch_read_dgram (void)
{
  return this->implementation ()->create_asynch_read_dgram ();
}

ACE_Asynch_Write_Dgram_Impl *
ACE_Proactor::create_asynch_write_dgram (void)
{
  return this->implementation ()->create_asynch_write_dgram ();
}

ACE_Asynch_Read_File_Impl *
ACE_Proactor::create_asynch_read_file (void)
{
  return this->implementation ()->create_asynch_read_file ();
}

ACE_Asynch_Write_File_Impl *
ACE_Proactor::create_asynch_write_file (void)
{
  return this->implementation ()->create_asynch_write_file ();
}

ACE_Asynch_Accept_Impl *
ACE_Proactor::create_asynch_accept (void)
{
  return this->implementation ()->create_asynch_accept ();
}

ACE_Asynch_Connect_Impl *
ACE_Proactor::create_asynch_connect (void)
{
  return this->implementation ()->create_asynch_connect ();
}

ACE_Asynch_Transmit_File_Impl *
ACE_Proactor::create_asynch_transmit_file (void)
{
  return this->implementation ()->create_asynch_transmit_file ();
}

 2)ACE_Asynch_Acceptor

ACE_Asynch_Acceptor an example of the Acceptor Pattern.

proactor需要定义ACE_Asynch_Acceptor。ACE_Asynch_Acceptor包含asynch_accept_对象，asynch_accept_对象的open方法创建了implementation_，implementation_的win32实现ACE_WIN32_Asynch_Accept又定义了proactor。

ACE_WIN32_Asynch_Accept::accept会创建ACE_WIN32_Asynch_Accept_Result，ACE_WIN32_Asynch_Accept_Result继承ACE_WIN32_Asynch_Result。ACE_WIN32_Asynch_Result::post_completion 就会调用win32_proactor。ACE_WIN32_Proactor::handle_events就会得到ACE_WIN32_Asynch_Result了。 

ACE_WIN32_Asynch_Result包含handler_，这个handler_就是ACE_Asynch_Acceptor对象。ACE_Asynch_Acceptor的handle_accept函数被调用时就会根据模板创建HANDLER *new_handler，然后调用open。

http://blog.csdn.net/ghosthjt/article/details/7624184

  ACE_Asynch_Acceptor<Receiver> acceptor;

  int Rc = -1 ;

  if ( host == NULL ) // Acceptor
    {
      // Simplify , initial read with  zero size
      Rc = acceptor.open (ACE_INET_Addr (port),0,1);

    }

void Receiver::open (ACE_HANDLE handle,
                     ACE_Message_Block &message_block)
{
...

template <class HANDLER>
class ACE_Asynch_Acceptor : public ACE_Handler
{
public:
  /// A do nothing constructor.
  ACE_Asynch_Acceptor (void);

  /// Virtual destruction
  virtual ~ACE_Asynch_Acceptor (void);
...
  /// Asynch_Accept used to make life easier :-)
  ACE_Asynch_Accept asynch_accept_;

class ACE_Export ACE_WIN32_Asynch_Accept : public virtual ACE_Asynch_Accept_Impl,
                                           public ACE_WIN32_Asynch_Operation
{
public:
  /// Constructor.
  ACE_WIN32_Asynch_Accept (ACE_WIN32_Proactor *win32_proactor);

  /**
   * This starts off an asynchronous accept.  The asynchronous accept
   * call also allows any initial data to be returned to the
   * <handler>.  Upto <bytes_to_read> will be read and stored in the
   * <message_block>.  The <accept_handle> will be used for the
   * <accept> call.  If (<accept_handle> == INVALID_HANDLE), a new
   * handle will be created.
   *
   * <message_block> must be specified. This is because the address of
   * the new connection is placed at the end of this buffer.
   */
  int accept (ACE_Message_Block &message_block,
              size_t bytes_to_read,
              ACE_HANDLE accept_handle,
              const void *act,
              int priority,
              int signal_number = 0);

  /// Destructor.
  ~ACE_WIN32_Asynch_Accept (void);

  // Methods belong to ACE_WIN32_Asynch_Operation base class. These
  // methods are defined here to avoid VC++ warnings. They route the
  // call to the ACE_WIN32_Asynch_Operation base class.

  /**
   * Initializes the factory with information which will be used with
   * each asynchronous call.  If (<handle> == ACE_INVALID_HANDLE),
   * <ACE_Handler::handle> will be called on the <handler> to get the
   * correct handle.
   */
  int open (ACE_Handler &handler,
            ACE_HANDLE handle,
            const void *completion_key,
            ACE_Proactor *proactor);

  /**
   * This cancels all pending accepts operations that were issued by
   * the calling thread.  The function does not cancel asynchronous
   * operations issued by other threads.
   */
  int cancel (void);

  /// Return the underlying proactor.
  ACE_Proactor* proactor (void) const;
};

class ACE_Export ACE_Asynch_Accept : public ACE_Asynch_Operation
{

public:
  /// A do nothing constructor.
  ACE_Asynch_Accept (void);

  /// Destructor.
  virtual ~ACE_Asynch_Accept (void);

  /**
   * Initializes the factory with information which will be used with
   * each asynchronous call. If (<handle> == ACE_INVALID_HANDLE),
   * <ACE_Handler::handle> will be called on the <handler> to get the
   * correct handle.
   */
  int open (ACE_Handler &handler,
            ACE_HANDLE handle = ACE_INVALID_HANDLE,
            const void *completion_key = 0,
            ACE_Proactor *proactor = 0);

  /**
   * This starts off an asynchronous accept.  The asynchronous accept
   * call also allows any initial data to be returned to the
   * <handler>.  Upto <bytes_to_read> will be read and stored in the
   * <message_block>.  The <accept_handle> will be used for the
   * <accept> call.  If (<accept_handle> == INVALID_HANDLE), a new
   * handle will be created. Priority of the
   * operation is specified by <priority>. On POSIX4-Unix, this is
   * supported. Works like <nice> in Unix. Negative values are not
   * allowed. 0 means priority of the operation same as the process
   * priority. 1 means priority of the operation is one less than
   * process. And so forth. On Win32, this is a no-op.
   *
   * <message_block> must be specified. This is because the address of
   * the new connection is placed at the end of this buffer.
   * <signal_number> is the POSIX4 real-time signal number to be used
   * for the operation. <signal_number> ranges from ACE_SIGRTMIN to
   * ACE_SIGRTMAX. This argument is a no-op on non-POSIX4 systems.
   */
  int accept (ACE_Message_Block &message_block,
              size_t bytes_to_read,
              ACE_HANDLE accept_handle = ACE_INVALID_HANDLE,
              const void *act = 0,
              int priority = 0,
              int signal_number = ACE_SIGRTMIN);

  /// Return the underlying implementation class.
  //  (this should be protected...)
  virtual ACE_Asynch_Operation_Impl *implementation (void) const;

protected:
  /// Delegation/implementation class that all methods will be
  /// forwarded to.
  ACE_Asynch_Accept_Impl *implementation_;

int
ACE_Asynch_Accept::open (ACE_Handler &handler,
                         ACE_HANDLE handle,
                         const void *completion_key,
                         ACE_Proactor *proactor)
{
  // Get a proactor for/from the user.
  proactor = this->get_proactor (proactor, handler);

  // Now let us get the implementation initialized.
  if ((this->implementation_ = proactor->create_asynch_accept ()) == 0)
    return -1;

  // Call the <open> method of the base class.
  return ACE_Asynch_Operation::open (handler,
                                     handle,
                                     completion_key,
                                     proactor);
}