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// -*- C++ -*-
//=============================================================================
/**
* @file FT_Round_Robin.h
*
* @author Kevin Stanley <stanleyk@ociweb.com>
*/
//=============================================================================
#ifndef FT_ROUND_ROBIN_H
#define FT_ROUND_ROBIN_H
#include /**/ "ace/pre.h"
#include "ace/Null_Mutex.h"
# if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
# endif /* ACE_LACKS_PRAGMA_ONCE */
#include "orbsvcs/Naming/FaultTolerant/FT_Location_Index_Map.h"
#include "orbsvcs/CosLoadBalancingS.h"
#include "ace/Vector_T.h"
#include "orbsvcs/Naming/FaultTolerant/ftnaming_export.h"
TAO_BEGIN_VERSIONED_NAMESPACE_DECL
class TAO_FT_Naming_Manager;
/**
* @class TAO_LB_RoundRobin_Strategy
*
* @brief "Round Robin" load balancing strategy used by the
* TAO_FT_Naming_Service.
*
* This load balancing strategy is designed to select an object group
* member residing at the next location from an object group managed
* by a specific Naming Manager. It selects an object from the object
* group in the order in which they are stored.
*/
class TAO_FtNaming_Export TAO_FT_Round_Robin
{
public:
/// Constructor.
TAO_FT_Round_Robin ();
/// This function obtains the next object's location as it is bound
/// within the object group.
/// @param naming_manager The TAO_FT_Naming_Manager which houses the
/// object groups.
/// @param location The resulting location
/// @param object_group The object group from which the object is to
/// be selected
/// @return False on error. Returns true if a valid object can
/// be selected using the Round Robin load balancing strategy.
virtual bool next_location (
PortableGroup::ObjectGroup_ptr object_group,
TAO_FT_Naming_Manager *naming_manager,
PortableGroup::Location& location);
/// Destructor
virtual ~TAO_FT_Round_Robin () = default;
private:
/// Lock used to ensure atomic access to state retained by this
/// class.
TAO_SYNCH_MUTEX lock_;
/// Table that maps PortableGroup::ObjectGroupId to location
/// sequence index specific to a given object group.
/**
* The location sequence corresponds to the sequence containing the
* locations of the members of a given object group. The value
* stored in this map corresponds to the index of the next element
* in that sequence. For example, if the index stored in the map is
* 2, location[2] will be used when retrieving the object reference
* to be returned from the Strategy::next_member() method.
*/
TAO_FT_Location_Index_Map location_index_map_;
};
TAO_END_VERSIONED_NAMESPACE_DECL
#include /**/ "ace/post.h"
#endif /* FT_ROUND_ROBIN_H */
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