#if NET_4_0
//
// ThreadLocal.cs
//
// Author:
// Jrmie "Garuma" Laval <jeremie.laval@gmail.com>
//
// Copyright (c) 2009 Jrmie "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.
using System;
using System.Runtime.Serialization;
using System.Runtime.InteropServices;
using System.Security.Permissions;
namespace System.Threading{
[HostProtectionAttribute(SecurityAction.LinkDemand, Synchronization = true,
ExternalThreading = true)]
public class ThreadLocal<T> : IDisposable
{
readonly Func<T> initializer;
LocalDataStoreSlot localStore;
class DataSlotWrapper
{
public bool Init;
public Func<T> Getter;
}
public ThreadLocal () : this (LazyInitializer.GetDefaultCtorValue<T>)
{
}
public ThreadLocal (Func<T> initializer)
{
if (initializer == null)
throw new ArgumentNullException ("initializer");
localStore = Thread.AllocateDataSlot ();
this.initializer = initializer;
}
public void Dispose ()
{
Dispose(true);
}
protected virtual void Dispose (bool dispManagedRes)
{
}
public bool IsValueCreated {
get {
return IsInitializedThreadLocal ();
}
}
public T Value {
get {
return GetValueThreadLocal ();
}
}
public override string ToString ()
{
return string.Format("[ThreadLocal: IsValueCreated={0}, Value={1}]", IsValueCreated, Value);
}
T GetValueThreadLocal ()
{
DataSlotWrapper myWrapper = Thread.GetData (localStore) as DataSlotWrapper;
// In case it's the first time the Thread access its data
if (myWrapper == null) {
myWrapper = DataSlotCreator ();
Thread.SetData (localStore, myWrapper);
}
return myWrapper.Getter();
}
bool IsInitializedThreadLocal ()
{
DataSlotWrapper myWrapper = (DataSlotWrapper)Thread.GetData (localStore);
if (myWrapper == null) {
myWrapper = DataSlotCreator ();
Thread.SetData (localStore, myWrapper);
}
return myWrapper.Init;
}
DataSlotWrapper DataSlotCreator ()
{
DataSlotWrapper wrapper = new DataSlotWrapper ();
Func<T> valSelector = initializer;
wrapper.Getter = delegate {
T val = valSelector ();
wrapper.Init = true;
wrapper.Getter = delegate { return val; };
return val;
};
return wrapper;
}
}
}
#endif
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