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