69 lines
1.9 KiB
C#
69 lines
1.9 KiB
C#
// <copyright file="SafeBitVector32.cs" company="Microsoft">
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// Copyright (c) 2009 Microsoft Corporation. All rights reserved.
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// </copyright>
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using System;
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using System.Threading;
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namespace System.Runtime.Caching {
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//
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// This is a multithreadsafe version of System.Collections.Specialized.BitVector32.
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//
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[Serializable]
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internal struct SafeBitVector32 {
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private volatile int _data;
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internal bool this[int bit] {
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get {
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int data = _data;
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return (data & bit) == bit;
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}
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set {
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for (;;) {
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int oldData = _data;
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int newData;
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if (value) {
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newData = oldData | bit;
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}
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else {
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newData = oldData & ~bit;
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}
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#pragma warning disable 0420
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int result = Interlocked.CompareExchange(ref _data, newData, oldData);
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#pragma warning restore 0420
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if (result == oldData) {
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break;
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}
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}
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}
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}
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internal bool ChangeValue(int bit, bool value) {
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for (;;) {
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int oldData = _data;
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int newData;
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if (value) {
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newData = oldData | bit;
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}
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else {
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newData = oldData & ~bit;
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}
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if (oldData == newData) {
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return false;
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}
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#pragma warning disable 0420
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int result = Interlocked.CompareExchange(ref _data, newData, oldData);
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#pragma warning restore 0420
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if (result == oldData) {
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return true;
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}
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}
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}
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}
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}
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