95 lines
2.3 KiB
C#
95 lines
2.3 KiB
C#
//------------------------------------------------------------------------------
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// <copyright file="ReadWriteObjectLock.cs" company="Microsoft">
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// Copyright (c) Microsoft Corporation. All rights reserved.
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// </copyright>
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//------------------------------------------------------------------------------
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/*
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* ReadWriteObjectLock
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*
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* Copyright (c) 1998-1999, Microsoft Corporation
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*
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*/
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namespace System.Web.Util {
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using System.Runtime.Serialization.Formatters;
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using System.Threading;
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class ReadWriteObjectLock {
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// Assumption:
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// -1 = a writer has the lock
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// 0 = no one has the lock
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// >0 = number of readers using the lock
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private int _lock;
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internal ReadWriteObjectLock() {
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}
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internal virtual void AcquireRead() {
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lock(this) {
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while (_lock == -1) {
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try {
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Monitor.Wait(this);
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}
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catch (ThreadInterruptedException) {
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// Just keep looping
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}
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}
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_lock++;
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}
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}
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internal virtual void ReleaseRead() {
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lock(this) {
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Debug.Assert(_lock > 0);
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_lock--;
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if (_lock == 0) {
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Monitor.PulseAll(this);
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}
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}
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}
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internal virtual void AcquireWrite() {
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lock(this) {
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while (_lock != 0) {
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try {
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Monitor.Wait(this);
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}
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catch (ThreadInterruptedException) {
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// Just keep looping
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}
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}
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_lock = -1;
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}
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}
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internal virtual void ReleaseWrite() {
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lock(this) {
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Debug.Assert(_lock == -1);
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_lock = 0;
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Monitor.PulseAll(this);
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}
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}
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/*
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internal virtual void AssertReadLock() {
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#if DBG
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Debug.Assert(_lock > 0);
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#endif
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}
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internal virtual void AssertWriteLock() {
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#if DBG
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Debug.Assert(_lock == -1);
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#endif
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}
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*/
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}
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}
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