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
|
/*
* Copyright (c) Contributors, http://opensimulator.org/
* See CONTRIBUTORS.TXT for a full list of copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the OpenSim Project nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
using System;
using System.Threading;
namespace OpenSim.Framework.Communications
{
internal class SimpleAsyncResult : IAsyncResult
{
private readonly AsyncCallback m_callback;
/// <summary>
/// Is process completed?
/// </summary>
/// <remarks>Should really be boolean, but VolatileRead has no boolean method</remarks>
private byte m_completed;
/// <summary>
/// Did process complete synchronously?
/// </summary>
/// <remarks>I have a hard time imagining a scenario where this is the case, again, same issue about
/// booleans and VolatileRead as m_completed
/// </remarks>
private byte m_completedSynchronously;
private readonly object m_asyncState;
private ManualResetEvent m_waitHandle;
private Exception m_exception;
internal SimpleAsyncResult(AsyncCallback cb, object state)
{
m_callback = cb;
m_asyncState = state;
m_completed = 0;
m_completedSynchronously = 1;
}
#region IAsyncResult Members
public object AsyncState
{
get { return m_asyncState; }
}
public WaitHandle AsyncWaitHandle
{
get
{
if (m_waitHandle == null)
{
bool done = IsCompleted;
ManualResetEvent mre = new ManualResetEvent(done);
if (Interlocked.CompareExchange(ref m_waitHandle, mre, null) != null)
{
mre.Close();
}
else
{
if (!done && IsCompleted)
{
m_waitHandle.Set();
}
}
}
return m_waitHandle;
}
}
public bool CompletedSynchronously
{
get { return Thread.VolatileRead(ref m_completedSynchronously) == 1; }
}
public bool IsCompleted
{
get { return Thread.VolatileRead(ref m_completed) == 1; }
}
#endregion
#region class Methods
internal void SetAsCompleted(bool completedSynchronously)
{
m_completed = 1;
if (completedSynchronously)
m_completedSynchronously = 1;
else
m_completedSynchronously = 0;
SignalCompletion();
}
internal void HandleException(Exception e, bool completedSynchronously)
{
m_completed = 1;
if (completedSynchronously)
m_completedSynchronously = 1;
else
m_completedSynchronously = 0;
m_exception = e;
SignalCompletion();
}
private void SignalCompletion()
{
if (m_waitHandle != null) m_waitHandle.Set();
if (m_callback != null) m_callback(this);
}
public void EndInvoke()
{
// This method assumes that only 1 thread calls EndInvoke
if (!IsCompleted)
{
// If the operation isn't done, wait for it
AsyncWaitHandle.WaitOne();
AsyncWaitHandle.Close();
m_waitHandle = null; // Allow early GC
}
// Operation is done: if an exception occured, throw it
if (m_exception != null) throw m_exception;
}
#endregion
}
internal class AsyncResult<T> : SimpleAsyncResult
{
private T m_result = default(T);
public AsyncResult(AsyncCallback asyncCallback, Object state) :
base(asyncCallback, state)
{
}
public void SetAsCompleted(T result, bool completedSynchronously)
{
// Save the asynchronous operation's result
m_result = result;
// Tell the base class that the operation completed
// sucessfully (no exception)
base.SetAsCompleted(completedSynchronously);
}
public new T EndInvoke()
{
base.EndInvoke();
return m_result;
}
}
}
|
