Replaced SynchronizedDictionary with ConcurrentDictionary

[snakefoot]

Replaced home-grown SynchronizedDictionary with ConcurrentDictionary.

Believe the special GetOrAddWithoutTakingLock-method was there because SynchronizedDictionary used non-recursive ReaderWriterLockSlim (faster than recursive). The factory-lock has been changed to a standard monitor-lock with recursion support, so special method is no longer needed.

Made a small optimization in GetAllInterfaces where the performance test from #744 arrived with empty-array, which triggered HashSet-allocation. Now it just returns empty-array without HashSet-allocation.

Made a small optimization in EnsureValidBaseType by skipping constructor-reflection for known typeof(object)

See also: #743

[snakefoot]

Took the performance-test from #744 (Removed the Task.Delay logic). And this PullRequest changed the performance time from 250ms to 185ms on my machine.

So it seems the existing ReaderWriterLockSlim is doing an okay job of handling concurrency. And this pull-request will not explode any performance barriers. But I think using ConcurrentDictionary is making the code prettier and less exotic.

// Copyright 2004-2021 Castle Project - http://www.castleproject.org/
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

namespace Castle.DynamicProxy.Tests
{
	using System;
	using System.Diagnostics;
	using System.Linq;
	using System.Reflection;
	using System.Security.Permissions;
	using System.Threading;
	using System.Threading.Tasks;

	using Castle.Core.Logging;
	using Castle.DynamicProxy.Generators;
	using Castle.DynamicProxy.Tests.Classes;

	using NUnit.Framework;

	[TestFixture]
	public class ProxyGeneratorPerfTest
	{
		[Test]
		public async Task Perf_Under_Heavy_Load()
		{
			var generator = new ProxyGenerator();
			int stressLevel = Environment.ProcessorCount;

			Type[] types = [typeof(I1), typeof(I2), typeof(I3), typeof(I4), typeof(I5)];
			var tasks = new Task[stressLevel];

			ManualResetEvent manualResetEvent = new ManualResetEvent(false);

			for (int i = 0; i < stressLevel; i++)
			{
				var iCopy = i;

				tasks[i] = Task.Run(() => {
					manualResetEvent.WaitOne();
					for (int i =0; i < 50000; i++)
						generator.CreateInterfaceProxyWithoutTarget(types[iCopy % types.Length]);
				});
			}

			manualResetEvent.Set();

			var sw = Stopwatch.StartNew();
			await Task.WhenAll(tasks);
			sw.Stop();
			var elapsed = sw.ElapsedMilliseconds;
			Console.WriteLine(elapsed);
		}
	}

	internal interface I1
	{
		void M1();
		void M2();
	}

	internal interface I2
	{
		void M1();
		void M2();
	}

	internal interface I3
	{
		void M1();
		void M2();
	}

	internal interface I4
	{
		void M1();
		void M2();
	}

	internal interface I5
	{
		void M1();
		void M2();
	}
}

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