#if NET_4_0 || BOOTSTRAP_NET_4_0
// AtomicBoolean.cs
//
// Copyright (c) 2008 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;
namespace System.Threading{
internal class AtomicBoolean
{
int flag;
const int UnSet = 0;
const int Set = 1;
public bool CompareAndExchange (bool expected, bool newVal)
{
int newTemp = newVal ? Set : UnSet;
int expectedTemp = expected ? Set : UnSet;
return Interlocked.CompareExchange (ref flag, newTemp, expectedTemp) == expectedTemp;
}
public static AtomicBoolean FromValue (bool value)
{
AtomicBoolean temp = new AtomicBoolean ();
temp.Value = value;
return temp;
}
public bool TrySet ()
{
return !Exchange (true);
}
public bool Exchange (bool newVal)
{
int newTemp = newVal ? Set : UnSet;
return Interlocked.Exchange (ref flag, newTemp) == Set;
}
public bool Value {
get {
return flag == Set;
}
set {
Exchange (value);
}
}
public bool Equals (AtomicBoolean rhs)
{
return this.flag == rhs.flag;
}
public override bool Equals (object rhs)
{
return rhs is AtomicBoolean ? Equals ((AtomicBoolean)rhs) : false;
}
public override int GetHashCode ()
{
return flag.GetHashCode ();
}
public static explicit operator bool (AtomicBoolean rhs)
{
return rhs.Value;
}
public static implicit operator AtomicBoolean (bool rhs)
{
return AtomicBoolean.FromValue (rhs);
}
}
}
#endif
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