Benchmarks added & reorganized.

POC/ArraySizeLimitBenchmarks.cs

@@ -0,0 +1,73 @@
+// Ignore Spelling: Poc
+
+using BenchmarkDotNet.Attributes;
+using Collections.Benchmarks.Core;
+using System.Buffers;
+
+namespace Recyclable.Collections.Benchmarks.POC
+{
+	public enum ArraySizeLimitBenchmarkType
+	{
+		ArraySizeLimit
+	}
+
+	public class ArraySizeLimitBenchmarks : BaselineVsActualBenchmarkBase<ArraySizeLimitBenchmarkType>
+	{
+		public static void Run()
+		{
+			var benchmark = new ArraySizeLimitBenchmarks();
+			benchmark.Setup();
+			FindArraySizeLimit();
+			benchmark.Cleanup();
+		}
+
+		[Params(2_147_483_605)]
+		public override int TestObjectCount { get => base.TestObjectCount; set => base.TestObjectCount = value; }
+
+		[Benchmark(OperationsPerInvoke = 1)]
+		public void Max_Allowed_Size_2_147_483_605()
+		{
+			long[] arr = ArrayPool<long>.Shared.Rent(TestObjectCount);
+			DoNothing.With(arr);
+		}
+
+		[Benchmark(OperationsPerInvoke = 1)]
+		public static void FindArraySizeLimit()
+		{
+			var pool = ArrayPool<long>.Shared;
+			var bufferSize = int.MaxValue / 2;
+			var oldValue = 0;
+			while (true)
+			{
+				try
+				{
+					Console.Write($"Allocating {bufferSize}...");
+					var arr = pool.Rent(bufferSize);
+					Console.WriteLine("success");
+					pool.Return(arr);
+					arr = null;
+
+					var nextValue = bufferSize - oldValue;
+					oldValue = bufferSize;
+					bufferSize = checked(bufferSize + nextValue);
+
+					GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced, true, true);
+				}
+				catch (Exception)
+				{
+					Console.WriteLine("error");
+					var nextValue = (bufferSize - oldValue) >> 1;
+					if (nextValue == 0)
+					{
+						break;
+					}
+
+					bufferSize = oldValue + nextValue;
+				}
+			}
+
+			Console.WriteLine("All done");
+			throw new Exception($"Everything was successful. You can create {oldValue} byte big arrays. Exception is logged to prevent more benchmarks.");
+		}
+	}
+}