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
|
// -*- C++ -*-
// $Id$
// ============================================================================
//
// = LIBRARY
// TAO_LoadBalancing
//
// = FILENAME
// ReplicaProxy.h
//
// = AUTHOR
// Ossama Othman <ossama@uci.edu>
//
// ============================================================================
#ifndef TAO_REPLICAPROXY_H
#define TAO_REPLICAPROXY_H
#include "ace/pre.h"
#include "ace/Synch.h"
#include "orbsvcs/LoadBalancingS.h"
#include "LoadBalancing_export.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
#if defined(_MSC_VER)
#if (_MSC_VER >= 1200)
#pragma warning(push)
#endif /* _MSC_VER >= 1200 */
#pragma warning(disable:4250)
#endif /* _MSC_VER */
class TAO_LB_LoadBalancer;
// Forward declaration
class TAO_LoadBalancing_Export TAO_LB_ReplicaProxy :
public virtual POA_LoadBalancing::ReplicaProxy,
public virtual PortableServer::RefCountServantBase
{
friend class TAO_LB_LoadBalancer;
public:
TAO_LB_ReplicaProxy (void);
CORBA::Float current_load (void) const;
// Read the stored load of the Object being load balanced from the
// ReplicaProxy.
CORBA::Object_ptr replica (void);
// Return a reference to the Replica.
virtual void current_load (CORBA::Float load,
CORBA::Environment &ACE_TRY_ENV)
ACE_THROW_SPEC ((CORBA::SystemException));
// Send the value of the current load on the Object being load
// balanced, where the definition of "load" is load balancing
// algorithm specific.
// @@ Ossama: i had to implement dampening mechanisms in the load,
// otherwise the spikes where killing me, but i'm not sure if that
// should be implemented in the client or the server.
// @@ I think that the 'Right Thing' is to have the client send
// 'instantaneous load' and get the load balancing service to do the
// dampening... that way we can modify the algorithm in the server,
// without affecting the client, or detect rapid raises in load and
// react proactively to those...
virtual void disconnect (CORBA::Environment &ACE_TRY_ENV)
ACE_THROW_SPEC ((LoadBalancing::ReplicaProxy::NotConnected,
CORBA::SystemException));
// Send a request to disconnect from the LoadBalancer.
// @@ Ossama: could you please fix the mess i left here? it is my
// fault, but i was running short on time.
int has_high_load_;
// Has the high load advisory been sent
// @@ Ossama: i added this flag to avoid multiple nomimal load
// advisories and high load advisories to be sent.
LoadBalancing::ReplicaControl_var control_;
// Reference to the ReplicaControl.
private:
~TAO_LB_ReplicaProxy (void);
// Destructor is private to ensure that this object is allocated on
// the heap.
void connect (TAO_LB_LoadBalancer *balancer,
LoadBalancing::ReplicaControl_ptr control,
CORBA::Object_ptr replica,
CORBA::Environment &ACE_TRY_ENV)
ACE_THROW_SPEC ((LoadBalancing::ReplicaProxy::NilControl,
LoadBalancing::ReplicaProxy::NilReplica,
CORBA::SystemException));
// Register the ReplicaControl and the Object being load balanced
// with the ReplicaProxy.
private:
TAO_SYNCH_MUTEX lock_;
// Mutex used to ensure access ReplicaProxy state is atomic.
CORBA::Object_var replica_;
// Reference to the Object being load balanced.
TAO_LB_LoadBalancer *balancer_;
// Pointer to the Load Balancer this ReplicaProxy is registered
// with.
CORBA::Float current_load_;
// The current load on the Object being load balanced.
CORBA::Boolean connected_;
// 1 == currently connected to load balancer
// 0 == currently disconnected from load balancer
};
#if defined(__ACE_INLINE__)
#include "ReplicaProxy.i"
#endif /* __ACE_INLINE__ */
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
#pragma warning(pop)
#endif /* _MSC_VER */
#include "ace/post.h"
#endif /* TAO_REPLICAPROXY_H */
|
