Files
libremetaverse/LibreMetaverse/Threading/SpinReaderWriterLock.cs
2024-08-30 19:52:52 -05:00

96 lines
3.2 KiB
C#

/*
* Copyright (c) 2024, Sjofn LLC
* All rights reserved.
*
* - Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* - Neither the name of the openmetaverse.co nor the names
* of its contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
using System;
using LibreMetaverse.Threading.Disposers;
namespace LibreMetaverse.Threading
{
/// <summary>
/// A reader writer lock that uses SpinWait if it does not have the lock. If the locks are held for
/// to much time, this is CPU consuming.
/// In my general tests, it is about 20 times faster than ReaderWriterLockSlim class and two times
/// faster than the YieldReaderWriterLock.
/// </summary>
public sealed class SpinReaderWriterLock:
IReaderWriterLock
{
#region Fields
internal SpinReaderWriterLockSlim Lock;
#endregion
#region ReadLock
/// <summary>
/// Acquires a read lock that must be used in a using clause.
/// </summary>
public SpinReadLock ReadLock()
{
Lock.EnterReadLock();
return new SpinReadLock(this);
}
#endregion
#region UpgradeableLock
/// <summary>
/// Acquires a upgradeable read lock that must be used in a using clause.
/// </summary>
public SpinUpgradeableLock UpgradeableLock()
{
Lock.EnterUpgradeableLock();
return new SpinUpgradeableLock(this);
}
#endregion
#region WriteLock
/// <summary>
/// Acquires a write lock that must be used in a using clause.
/// If you are using a UpgradeableLock use the Upgrade method of the
/// YieldUpgradeableLock instead or you will cause a dead-lock.
/// </summary>
public SpinWriteLock WriteLock()
{
Lock.EnterWriteLock();
return new SpinWriteLock(this);
}
#endregion
#region IReaderWriterLock Members
IDisposable IReaderWriterLock.ReadLock()
{
return ReadLock();
}
IUpgradeableLock IReaderWriterLock.UpgradeableLock()
{
return UpgradeableLock();
}
IDisposable IReaderWriterLock.WriteLock()
{
return WriteLock();
}
#endregion
}
}