Asynch_Connector.h

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/* -*- C++ -*- */

//=============================================================================
/**
 *  @file    Asynch_Connector.h
 *
 *  Asynch_Connector.h,v 1.12 2005/11/27 12:11:35 ossama Exp
 *
 *  @author Alexander Libman <alibman@ihug.com.au>
 */
//=============================================================================

#ifndef ACE_ASYNCH_CONNECTOR_H
#define ACE_ASYNCH_CONNECTOR_H
#include /**/ "ace/pre.h"

#include "ace/config-all.h"

#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */

#if (defined (ACE_WIN32) || defined (ACE_HAS_AIO_CALLS)) && !defined(ACE_HAS_WINCE)
// This only works on platforms that support async i/o.

#include "ace/Asynch_IO.h"
#include "ace/INET_Addr.h"

ACE_BEGIN_VERSIONED_NAMESPACE_DECL

// Forward declarations
class ACE_Message_Block;

/**
 * @class ACE_Asynch_Connector
 *
 * @brief This class is an example of the Connector pattern.  This class
 * will establish new connections and create new HANDLER objects to handle
 * the new connections.
 *
 * Unlike the ACE_Connector, however, this class is designed to
 * be used asynchronously with the ACE Proactor framework.
 */

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

  /// Virtual destruction
  virtual ~ACE_Asynch_Connector (void);

  /**
   * This opens asynch connector
   */
  virtual int open (int pass_addresses = 0,
                    ACE_Proactor *proactor = 0,
                    int validate_new_connection = 1);

  /// This initiates a new asynchronous connect
  virtual int connect (const ACE_INET_Addr &remote_sap,
                       const ACE_INET_Addr &local_sap =
                         (const ACE_INET_Addr &)ACE_Addr::sap_any,
                       int reuse_addr = 1,
                       const void *act = 0);

  /**
   * This cancels all pending accepts operations that were issued by
   * the calling thread.
   *
   * @note On Windows, this method does not cancel connect operations
   *       issued by other threads.
   *
   * @note On POSIX, delegates cancelation to ACE_POSIX_Asynch_Connect.
   */
  virtual int cancel (void);


  /**
   * Template method to validate peer before service is opened.
   * This method is called when the connection attempt completes,
   * whether it succeeded or failed, if the @a validate_connection
   * argument to @c open() was non-zero or the @c validate_new_connection()
   * method is called to turn this feature on.  The default implementation
   * returns 0.  Users can (and probably should) reimplement this method
   * to learn about the success or failure of the connection attempt.
   * If the connection completed successfully, this method can be used to
   * perform validation of the peer using it's address, running an
   * authentication procedure (such as SSL) or anything else necessary or
   * desireable. The return value from this method determines whether or
   * not ACE will continue opening the service or abort the connection.
   *
   * @param result  Result of the connection acceptance. Use
   *                result.success() to determine success or failure of
   *                the connection attempt.
   * @param remote  Peer's address. If the connection failed, this object
   *                is undefined.
   * @param local   Local address connection was completed from. If the
   *                connection failed, this object is undefined.
   *
   * @retval  -1  ACE_Asynch_Connector will close the connection, and
   *              the service will not be opened.
   * @retval  0   Service opening will proceeed.
   * @return  Return value is ignored if the connection attempt failed.
   */
  virtual int validate_connection (const ACE_Asynch_Connect::Result& result,
                                   const ACE_INET_Addr &remote,
                                   const ACE_INET_Addr& local);

  //
  // These are low level tweaking methods
  //

  /// Set and get flag that indicates if parsing and passing of
  /// addresses to the service_handler is necessary.
  virtual int  pass_addresses (void) const;
  virtual void pass_addresses (int new_value);

  /// Set and get flag that indicates if address validation is
  /// required.
  virtual int  validate_new_connection (void) const;
  virtual void validate_new_connection (int new_value);

protected:

  /// This is called when an outstanding accept completes.
  virtual void handle_connect (const ACE_Asynch_Connect::Result &result);


  /// This parses the address from read buffer.
  void parse_address (const ACE_Asynch_Connect::Result &result,
                      ACE_INET_Addr &remote_address,
                      ACE_INET_Addr &local_address);

  /// Return the asynch Connect object.
  ACE_Asynch_Connect & asynch_connect (void);

  /**
   * This is the template method used to create new handler.
   * Subclasses must overwrite this method if a new handler creation
   * strategy is required.
   */
  virtual HANDLER *make_handler (void);

private:

  /// Asynch_Connect used to make life easier :-)
  ACE_Asynch_Connect asynch_connect_;

  /// Flag that indicates if parsing of addresses is necessary.
  int pass_addresses_;

  /// Flag that indicates if address validation is required.
  int validate_new_connection_;

};

ACE_END_VERSIONED_NAMESPACE_DECL

#if defined (ACE_TEMPLATES_REQUIRE_SOURCE)
#include "ace/Asynch_Connector.cpp"
#endif /* ACE_TEMPLATES_REQUIRE_SOURCE */

#if defined (ACE_TEMPLATES_REQUIRE_PRAGMA)
#pragma implementation ("Asynch_Connector.cpp")
#endif /* ACE_TEMPLATES_REQUIRE_PRAGMA */

#endif /* ACE_WIN32 || ACE_HAS_AIO_CALLS */
#include /**/ "ace/post.h"
#endif /* ACE_ASYNCH_CONNECTOR_H */

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