LegacyCacheLock.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using NHibernate.Cache;

namespace YourNamespace
{
	public class LegacyCacheLock : ICacheLock
	{
		class MonitorLock : IDisposable
		{
			private readonly object _lockObj;

			public MonitorLock(object lockObj)
			{
				Monitor.Enter(lockObj);
				_lockObj = lockObj;
			}

			public void Dispose()
			{
				Monitor.Exit(_lockObj);
			}
		}

		public void Dispose()
		{
		}

		public IDisposable ReadLock()
		{
			return CreateLock();
		}

		public IDisposable WriteLock()
		{
			return CreateLock();
		}

		public Task<IDisposable> WriteLockAsync()
		{
			return CreateAsyncLock();
		}

		public Task<IDisposable> ReadLockAsync()
		{
			return CreateAsyncLock();
		}

		private IDisposable CreateLock()
		{
			return new MonitorLock(this);
		}

		private Task<IDisposable> CreateAsyncLock()
		{
			try
			{
				return Task.FromResult<IDisposable>(CreateLock());
			}
			catch (Exception ex)
			{
				return Task.FromException<IDisposable>(ex);
			}
		}
	}

	public class LegacyCacheReadWriteLockFactory : ICacheReadWriteLockFactory
	{
		public ICacheLock Create()
		{
			return new LegacyCacheLock();
		}
	}
}