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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
//
// System.Runtime.Remoting.Identity.cs
//
// Author: Lluis Sanchez Gual (lluis@ideary.com)
//
// (C) 2003, Lluis Sanchez Gual
//
//
// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Threading;
using System.Collections;
namespace System.Runtime.Remoting.Lifetime
{
internal class Lease : MarshalByRefObject, ILease
{
DateTime _leaseExpireTime;
LeaseState _currentState;
TimeSpan _initialLeaseTime;
TimeSpan _renewOnCallTime;
TimeSpan _sponsorshipTimeout;
ArrayList _sponsors;
Queue _renewingSponsors;
RenewalDelegate _renewalDelegate;
delegate TimeSpan RenewalDelegate(ILease lease);
public Lease()
{
_currentState = LeaseState.Initial;
_initialLeaseTime = LifetimeServices.LeaseTime;
_renewOnCallTime = LifetimeServices.RenewOnCallTime;
_sponsorshipTimeout = LifetimeServices.SponsorshipTimeout;
_leaseExpireTime = DateTime.Now + _initialLeaseTime;
}
public TimeSpan CurrentLeaseTime
{
get { return _leaseExpireTime - DateTime.Now; }
}
public LeaseState CurrentState
{
get { return _currentState; }
}
public void Activate()
{
// Called when then Lease is registered in the LeaseManager
_currentState = LeaseState.Active;
}
public TimeSpan InitialLeaseTime
{
get { return _initialLeaseTime; }
set
{
if (_currentState != LeaseState.Initial)
throw new RemotingException ("InitialLeaseTime property can only be set when the lease is in initial state; state is " + _currentState + ".");
_initialLeaseTime = value;
_leaseExpireTime = DateTime.Now + _initialLeaseTime;
if (value == TimeSpan.Zero) _currentState = LeaseState.Null;
}
}
public TimeSpan RenewOnCallTime
{
get { return _renewOnCallTime; }
set
{
if (_currentState != LeaseState.Initial)
throw new RemotingException ("RenewOnCallTime property can only be set when the lease is in initial state; state is " + _currentState + ".");
_renewOnCallTime = value;
}
}
public TimeSpan SponsorshipTimeout
{
get { return _sponsorshipTimeout; }
set
{
if (_currentState != LeaseState.Initial)
throw new RemotingException ("SponsorshipTimeout property can only be set when the lease is in initial state; state is " + _currentState + ".");
_sponsorshipTimeout = value;
}
}
public void Register (ISponsor obj)
{
Register (obj, TimeSpan.Zero);
}
public void Register (ISponsor obj, TimeSpan renewalTime)
{
lock (this) {
if (_sponsors == null)
_sponsors = new ArrayList();
_sponsors.Add (obj);
}
if (renewalTime != TimeSpan.Zero)
Renew (renewalTime);
}
public TimeSpan Renew (TimeSpan renewalTime)
{
DateTime newTime = DateTime.Now + renewalTime;
if (newTime > _leaseExpireTime) _leaseExpireTime = newTime;
return CurrentLeaseTime;
}
public void Unregister (ISponsor obj)
{
lock (this) {
if (_sponsors == null) return;
// Don't use ArrayList.Remove() here because it will end calling Equals, which may
// crash if the sponsor is not available anymore
for (int n=0; n < _sponsors.Count; n++) {
if (object.ReferenceEquals (_sponsors [n], obj)) {
_sponsors.RemoveAt (n);
break;
}
}
}
}
internal void UpdateState ()
{
// Called by the lease manager to update the state of this lease,
// basically for knowing if it has expired
if (_currentState != LeaseState.Active) return;
if (CurrentLeaseTime > TimeSpan.Zero) return;
// Expired. Try to renew using sponsors.
if (_sponsors != null)
{
_currentState = LeaseState.Renewing;
lock (this) {
_renewingSponsors = new Queue (_sponsors);
}
CheckNextSponsor ();
}
else
_currentState = LeaseState.Expired;
}
void CheckNextSponsor ()
{
if (_renewingSponsors.Count == 0) {
_currentState = LeaseState.Expired;
_renewingSponsors = null;
return;
}
ISponsor nextSponsor = (ISponsor) _renewingSponsors.Peek();
_renewalDelegate = new RenewalDelegate (nextSponsor.Renewal);
IAsyncResult ar = _renewalDelegate.BeginInvoke (this, null, null);
ThreadPool.RegisterWaitForSingleObject (ar.AsyncWaitHandle, new WaitOrTimerCallback (ProcessSponsorResponse), ar, _sponsorshipTimeout, true);
}
void ProcessSponsorResponse (object state, bool timedOut)
{
if (!timedOut)
{
try
{
IAsyncResult ar = (IAsyncResult)state;
TimeSpan newSpan = _renewalDelegate.EndInvoke (ar);
if (newSpan != TimeSpan.Zero)
{
Renew (newSpan);
_currentState = LeaseState.Active;
_renewingSponsors = null;
return;
}
}
catch { }
}
// Sponsor failed, timed out, or returned TimeSpan.Zero
Unregister ((ISponsor) _renewingSponsors.Dequeue()); // Drop the sponsor
CheckNextSponsor ();
}
}
}
|