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//------------------------------------------------------------------------------
// <copyright file="SimpleBitVector32.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
using System;
using System.Threading;
namespace System.Web.Util {
//
// This is a multithreadsafe version of System.Collections.Specialized.BitVector32.
//
[Serializable]
internal struct SafeBitVector32 {
private volatile int _data;
internal SafeBitVector32(int data) {
this._data = data;
}
internal bool this[int bit] {
get {
int data = _data;
return (data & bit) == bit;
}
set {
for (;;) {
int oldData = _data;
int newData;
if (value) {
newData = oldData | bit;
}
else {
newData = oldData & ~bit;
}
#pragma warning disable 0420
int result = Interlocked.CompareExchange(ref _data, newData, oldData);
#pragma warning restore 0420
if (result == oldData) {
break;
}
}
}
}
internal bool ChangeValue(int bit, bool value) {
for (;;) {
int oldData = _data;
int newData;
if (value) {
newData = oldData | bit;
}
else {
newData = oldData & ~bit;
}
if (oldData == newData) {
return false;
}
#pragma warning disable 0420
int result = Interlocked.CompareExchange(ref _data, newData, oldData);
#pragma warning restore 0420
if (result == oldData) {
return true;
}
}
}
}
}
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