1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
|
// -*- C++ -*-
//=============================================================================
/**
* @file LB_LeastLoaded.h
*
* $Id$
*
* @author Ossama Othman <ossama@uci.edu>
*/
//=============================================================================
#ifndef LB_LEAST_LOADED_H
#define LB_LEAST_LOADED_H
#include "ace/pre.h"
#include "LB_LoadMap.h"
# if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
# endif /* ACE_LACKS_PRAGMA_ONCE */
#include "orbsvcs/CosLoadBalancingC.h"
#include "ace/Synch.h"
namespace TAO_LB
{
/**
* @name Default LeastLoaded strategy parameters.
*
* Defaults defined by the Load Balancing specification.
*/
const CORBA::Float LL_DEFAULT_CRITICAL_THRESHOLD = 0;
const CORBA::Float LL_DEFAULT_REJECT_THRESHOLD = 0;
const CORBA::Float LL_DEFAULT_TOLERANCE = 1;
const CORBA::Float LL_DEFAULT_DAMPENING = 0;
const CORBA::Float LL_DEFAULT_PER_BALANCE_LOAD = 0;
}
/**
* @class TAO_LB_LeastLoaded
*
* @brief "Least loaded" load balancing strategy
*
* This load balancing strategy is designed to select an object group
* member residing at a location with the smallest load.
*/
class TAO_LB_LeastLoaded
: public virtual CosLoadBalancing::Strategy,
public virtual CORBA::LocalObject
{
public:
/// Constructor.
TAO_LB_LeastLoaded (
CORBA::Float critical_threshold = TAO_LB::LL_DEFAULT_CRITICAL_THRESHOLD,
CORBA::Float reject_threshold = TAO_LB::LL_DEFAULT_REJECT_THRESHOLD,
CORBA::Float tolerance = TAO_LB::LL_DEFAULT_TOLERANCE,
CORBA::Float dampening = TAO_LB::LL_DEFAULT_DAMPENING,
CORBA::Float per_balance_load = TAO_LB::LL_DEFAULT_PER_BALANCE_LOAD);
/// Destructor.
~TAO_LB_LeastLoaded (void);
/**
* @name CosLoadBalancing::Strategy methods
*
* Methods required by the CosLoadBalancing::Strategy interface.
*/
//@{
virtual char * name (ACE_ENV_SINGLE_ARG_DECL_WITH_DEFAULTS)
ACE_THROW_SPEC ((CORBA::SystemException));
virtual CosLoadBalancing::Properties * get_properties (
ACE_ENV_SINGLE_ARG_DECL_WITH_DEFAULTS)
ACE_THROW_SPEC ((CORBA::SystemException));
virtual void push_loads (
const PortableGroup::Location & the_location,
const CosLoadBalancing::LoadList & loads
ACE_ENV_ARG_DECL_WITH_DEFAULTS)
ACE_THROW_SPEC ((CORBA::SystemException));
virtual CORBA::Object_ptr next_member (
PortableGroup::ObjectGroup_ptr object_group,
CosLoadBalancing::LoadManager_ptr load_manager
ACE_ENV_ARG_DECL_WITH_DEFAULTS)
ACE_THROW_SPEC ((CORBA::SystemException,
PortableGroup::ObjectGroupNotFound,
PortableGroup::MemberNotFound));
// virtual void analyze_loads (
// PortableGroup::ObjectGroup_ptr object_group,
// CosLoadBalancing::LoadManager_ptr load_manager
// ACE_ENV_ARG_DECL_WITH_DEFAULTS)
// ACE_THROW_SPEC ((CORBA::SystemException));
//@}
protected:
/// Retrieve the least loaded location from the given list of
/// locations.
CORBA::Boolean get_location (PortableGroup::ObjectGroup_ptr object_group,
CosLoadBalancing::LoadManager_ptr load_manager,
const PortableGroup::Locations & locations,
PortableGroup::Location & location
ACE_ENV_ARG_DECL);
/// Return the effective load.
CORBA::Float effective_load (CORBA::Float previous_load,
CORBA::Float new_load);
/// Push the new load into this Strategy's load processor, and
/// return the corresponding effective load.
void push_loads (
const PortableGroup::Location & the_location,
const CosLoadBalancing::LoadList & loads,
CosLoadBalancing::Load & effective_load
ACE_ENV_ARG_DECL);
private:
/// Table that maps location to load list.
TAO_LB_LoadMap * load_map_;
/// Lock used to ensure atomic access to state retained by this
/// class.
TAO_SYNCH_MUTEX * lock_;
CORBA::Float critical_threshold_;
CORBA::Float reject_threshold_;
CORBA::Float tolerance_;
CORBA::Float dampening_;
CORBA::Float per_balance_load_;
};
#if defined (__ACE_INLINE__)
#include "LB_LeastLoaded.inl"
#endif /* defined INLINE */
#include "ace/post.h"
#endif /* LB_LEAST_LOADED_H */
|
