ConcurrentTest.cs

/*
BenchmarkDotNet=v0.12.0, OS=Windows 10.0.18363
Intel Core i7-6950X CPU 3.00GHz (Skylake), 1 CPU, 20 logical and 10 physical cores
  [Host]     : .NET Framework 4.8 (4.8.4121.0), X86 LegacyJIT
  DefaultJob : .NET Framework 4.8 (4.8.4121.0), X86 LegacyJIT


|        Method |     Mean |    Error |   StdDev |
|-------------- |---------:|---------:|---------:|
| LockTryGetSet | 28.42 ns | 0.006 ns | 0.006 ns |
|    LockTryGet | 28.33 ns | 0.012 ns | 0.010 ns |
|   CDTryGetSet | 15.78 ns | 0.001 ns | 0.001 ns |
|      CDTryGet | 13.75 ns | 0.006 ns | 0.005 ns |
*/

using System.Collections.Concurrent;
using System.Collections.Generic;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

namespace TestConcurrentCollectionPerf
{
	class Program
	{
		static void Main(string[] args)
		{
			BenchmarkRunner.Run (typeof(LockVsConcurrentDictionary));
		}
	}

	public class LockVsConcurrentDictionary
	{
		[GlobalSetup]
		public void Setup ()
		{
			this.values = new Dictionary<int, string> {
				{ 1, "test1" },
				{ 2000, "test2" }
			};

			this.cvalues = new ConcurrentDictionary<int, string> ();
			this.cvalues[1] = "test1";
			this.cvalues[2000] = "test2";
		}

		[Benchmark]
		public void LockTryGetSet ()
		{
			lock (this.sync) {
				if (!this.values.TryGetValue (3000, out string value))
					this.values[3000] = "value";
			}
		}

		[Benchmark]
		public void LockTryGet ()
		{
			lock (this.sync) {
				this.values.TryGetValue (2000, out string value);
			}
		}

		[Benchmark]
		public void CDTryGetSet ()
		{
			this.cvalues.GetOrAdd (3000, (k) => "value");
		}

		[Benchmark]
		public void CDTryGet ()
		{
			this.cvalues.TryGetValue (2000, out string value);
		}

		private ConcurrentDictionary<int, string> cvalues;
		private Dictionary<int, string> values;
		private readonly object sync = new object();
	}
}