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
|
//
// ThreadLocal.cs
//
// Author:
// Jérémie "Garuma" Laval <jeremie.laval@gmail.com>
// Rewritten by Paolo Molaro (lupus@ximian.com)
//
// Copyright (c) 2009 Jérémie "Garuma" Laval
//
// 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.
#if NET_4_0
using System;
using System.Collections.Generic;
using System.Runtime.Serialization;
using System.Runtime.InteropServices;
using System.Security.Permissions;
namespace System.Threading
{
[System.Diagnostics.DebuggerDisplay ("IsValueCreated={IsValueCreated}, Value={ValueForDebugDisplay}")]
public class ThreadLocal<T> : IDisposable
{
struct TlsDatum {
internal sbyte state; /* 0 uninitialized, < 0 initializing, > 0 inited */
internal Exception cachedException; /* this is per-thread */
internal T data;
}
Func<T> valueFactory;
/* The tlsdata field is handled magically by the JIT
* It must be a struct and it is always accessed by ldflda: the JIT, instead of
* computing the address inside the instance, will return the address of the variable
* for the current thread (based on tls_offset). This magic wouldn't be needed if C#
* let us declare an icall with a TlsDatum& return type...
* For this same reason, we must check tls_offset for != 0 to make sure it's valid before accessing tlsdata
* The address of the tls var is cached per method at the first IL ldflda instruction, so care must be taken
* not to cause it to be conditionally executed.
*/
uint tls_offset;
TlsDatum tlsdata;
public ThreadLocal ()
{
tls_offset = Thread.AllocTlsData (typeof (TlsDatum));
}
public ThreadLocal (Func<T> valueFactory) : this ()
{
if (valueFactory == null)
throw new ArgumentNullException ("valueFactory");
this.valueFactory = valueFactory;
}
#if NET_4_5
public ThreadLocal (bool trackAllValues) : this () {
if (trackAllValues)
throw new NotImplementedException ();
}
public ThreadLocal (Func<T> valueFactory, bool trackAllValues) : this (valueFactory) {
if (trackAllValues)
throw new NotImplementedException ();
}
#endif
public void Dispose ()
{
Dispose (true);
}
protected virtual void Dispose (bool disposing)
{
if (tls_offset != 0) {
uint o = tls_offset;
tls_offset = 0;
if (disposing)
valueFactory = null;
Thread.DestroyTlsData (o);
GC.SuppressFinalize (this);
}
}
~ThreadLocal ()
{
Dispose (false);
}
public bool IsValueCreated {
get {
if (tls_offset == 0)
throw new ObjectDisposedException ("ThreadLocal object");
/* ALERT! magic tlsdata JIT access redirects to TLS value instead of instance field */
return tlsdata.state > 0;
}
}
T GetSlowPath () {
/* ALERT! magic tlsdata JIT access redirects to TLS value instead of instance field */
if (tlsdata.cachedException != null)
throw tlsdata.cachedException;
if (tlsdata.state < 0)
throw new InvalidOperationException ("The initialization function attempted to reference Value recursively");
tlsdata.state = -1;
if (valueFactory != null) {
try {
tlsdata.data = valueFactory ();
} catch (Exception ex) {
tlsdata.cachedException = ex;
throw ex;
}
} else {
tlsdata.data = default (T);
}
tlsdata.state = 1;
return tlsdata.data;
}
[System.Diagnostics.DebuggerBrowsableAttribute (System.Diagnostics.DebuggerBrowsableState.Never)]
public T Value {
get {
if (tls_offset == 0)
throw new ObjectDisposedException ("ThreadLocal object");
/* ALERT! magic tlsdata JIT access redirects to TLS value instead of instance field */
if (tlsdata.state > 0)
return tlsdata.data;
return GetSlowPath ();
}
set {
if (tls_offset == 0)
throw new ObjectDisposedException ("ThreadLocal object");
/* ALERT! magic tlsdata JIT access redirects to TLS value instead of instance field */
tlsdata.state = 1;
tlsdata.data = value;
}
}
#if NET_4_5
public IList<T> Values {
get {
if (tls_offset == 0)
throw new ObjectDisposedException ("ThreadLocal object");
throw new NotImplementedException ();
}
}
#endif
public override string ToString ()
{
return Value.ToString ();
}
}
}
#endif
|
