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Moved Lazy to the TPL where it belongs
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‎System.Threading.Tasks.Net35.csproj‎

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<Compile Include="System.Collections.Concurrent.Partitioners\UserRangePartitioner.cs" />
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<Compile Include="System.Collections.Generic\GenericEqualityComparer.cs" />
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<Compile Include="System.Collections.Generic\DefaultEqualityComparer.cs" />
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<Compile Include="System\Lazy.cs" />
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<Compile Include="System\LazyThreadSafetyMode.cs" />
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</ItemGroup>
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<ItemGroup>
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<Folder Include="System.Collections.Concurrent\" />

‎System/Lazy.cs‎

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//
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// Lazy.cs
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//
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// Authors:
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// Zoltan Varga (vargaz@gmail.com)
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// Marek Safar (marek.safar@gmail.com)
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//
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// Copyright (C) 2009 Novell
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//
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// Permission is hereby granted, free of charge, to any person obtaining
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// a copy of this software and associated documentation files (the
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// "Software"), to deal in the Software without restriction, including
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// without limitation the rights to use, copy, modify, merge, publish,
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// distribute, sublicense, and/or sell copies of the Software, and to
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// permit persons to whom the Software is furnished to do so, subject to
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// the following conditions:
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//
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// The above copyright notice and this permission notice shall be
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// included in all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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//
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using System;
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using System.Runtime.Serialization;
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using System.Runtime.InteropServices;
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using System.Security.Permissions;
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using System.Threading;
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using System.Diagnostics;
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namespace System
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{
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[SerializableAttribute]
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[ComVisibleAttribute(false)]
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[HostProtectionAttribute(SecurityAction.LinkDemand, Synchronization = true, ExternalThreading = true)]
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[DebuggerDisplay ("ThreadSafetyMode={Mode}, IsValueCreated={IsValueCreated}, IsValueFaulted={IsValueFaulted}, Value={ValueForDebugDisplay}")]
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public class Lazy<T>
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{
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T value;
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Func<T> factory;
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object monitor;
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Exception exception;
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LazyThreadSafetyMode mode;
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bool inited;
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public Lazy ()
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: this (LazyThreadSafetyMode.ExecutionAndPublication)
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{
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}
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public Lazy (Func<T> valueFactory)
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: this (valueFactory, LazyThreadSafetyMode.ExecutionAndPublication)
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{
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}
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public Lazy (bool isThreadSafe)
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: this (Activator.CreateInstance<T>, isThreadSafe ? LazyThreadSafetyMode.ExecutionAndPublication : LazyThreadSafetyMode.None)
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{
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}
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public Lazy (Func<T> valueFactory, bool isThreadSafe)
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: this (valueFactory, isThreadSafe ? LazyThreadSafetyMode.ExecutionAndPublication : LazyThreadSafetyMode.None)
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{
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}
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public Lazy (LazyThreadSafetyMode mode)
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: this (Activator.CreateInstance<T>, mode)
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{
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}
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public Lazy (Func<T> valueFactory, LazyThreadSafetyMode mode)
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{
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if (valueFactory == null)
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throw new ArgumentNullException ("valueFactory");
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this.factory = valueFactory;
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if (mode != LazyThreadSafetyMode.None)
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monitor = new object ();
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this.mode = mode;
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}
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// Don't trigger expensive initialization
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[DebuggerBrowsable (DebuggerBrowsableState.Never)]
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public T Value {
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get {
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if (inited)
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return value;
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if (exception != null)
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throw exception;
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return InitValue ();
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}
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}
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T InitValue ()
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{
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Func<T> init_factory;
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T v;
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switch (mode) {
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case LazyThreadSafetyMode.None:
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init_factory = factory;
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if (init_factory == null) {
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if (exception == null)
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throw new InvalidOperationException ("The initialization function tries to access Value on this instance");
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throw exception;
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}
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try {
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factory = null;
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v = init_factory ();
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value = v;
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Thread.MemoryBarrier ();
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inited = true;
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} catch (Exception ex) {
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exception = ex;
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throw;
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}
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break;
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case LazyThreadSafetyMode.PublicationOnly:
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init_factory = factory;
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//exceptions are ignored
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if (init_factory != null)
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v = init_factory ();
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else
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v = default (T);
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lock (monitor) {
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if (inited)
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return value;
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value = v;
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Thread.MemoryBarrier ();
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inited = true;
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factory = null;
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}
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break;
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case LazyThreadSafetyMode.ExecutionAndPublication:
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lock (monitor) {
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if (inited)
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return value;
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if (factory == null) {
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if (exception == null)
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throw new InvalidOperationException ("The initialization function tries to access Value on this instance");
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throw exception;
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}
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init_factory = factory;
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try {
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factory = null;
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v = init_factory ();
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value = v;
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Thread.MemoryBarrier ();
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inited = true;
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} catch (Exception ex) {
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exception = ex;
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throw;
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}
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}
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break;
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default:
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throw new InvalidOperationException ("Invalid LazyThreadSafetyMode " + mode);
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}
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return value;
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}
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public bool IsValueCreated {
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get {
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return inited;
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}
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}
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public override string ToString ()
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{
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if (inited)
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return value.ToString ();
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else
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return "Value is not created";
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}
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}
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}

‎System/LazyThreadSafetyMode.cs‎

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//
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// Lazy.cs
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//
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// Authors:
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// Rodrigo Kumpera (kumpera@gmail.com)
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//
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// Copyright (C) 2010 Novell
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//
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// Permission is hereby granted, free of charge, to any person obtaining
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// a copy of this software and associated documentation files (the
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// "Software"), to deal in the Software without restriction, including
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// without limitation the rights to use, copy, modify, merge, publish,
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// distribute, sublicense, and/or sell copies of the Software, and to
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// permit persons to whom the Software is furnished to do so, subject to
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// the following conditions:
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//
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// The above copyright notice and this permission notice shall be
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// included in all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23+
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26+
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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//
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using System;
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namespace System.Threading
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{
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public enum LazyThreadSafetyMode
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{
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None,
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PublicationOnly,
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ExecutionAndPublication
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}
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}

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