Add JitStatsDiagnoserAttribute (#2250)

Author: KeterSCP

docs/articles/configs/diagnosers.md

@@ -11,6 +11,9 @@ The current Diagnosers are:
 
 - GC and Memory Allocation (`MemoryDiagnoser`) which is cross platform, built-in and **is not enabled by default anymore**.
   Please see Adam Sitnik's [blog post](https://adamsitnik.com/the-new-Memory-Diagnoser/) for all the details.
+- JIT Stats Diagnoser.
+  You can find this diagnoser in a separate package with diagnosers for Windows (`BenchmarkDotNet.Diagnostics.Windows`):
+  [![NuGet](https://img.shields.io/nuget/v/BenchmarkDotNet.svg)](https://www.nuget.org/packages/BenchmarkDotNet.Diagnostics.Windows/)
 - JIT Inlining Events (`InliningDiagnoser`).
   You can find this diagnoser in a separate package with diagnosers for Windows (`BenchmarkDotNet.Diagnostics.Windows`):
   [![NuGet](https://img.shields.io/nuget/v/BenchmarkDotNet.svg)](https://www.nuget.org/packages/BenchmarkDotNet.Diagnostics.Windows/)
@@ -123,6 +126,8 @@ In BenchmarkDotNet, 1kB = 1024B, 1MB = 1024kB, and so on. The column Gen X means
 
 [!include[IntroTailcall](../samples/IntroTailcall.md)]
 
+[!include[IntroJitStatsDiagnoser](../samples/IntroJitStatsDiagnoser.md)]
+
 [!include[IntroNativeMemory](../samples/IntroNativeMemory.md)]
 
 [!include[IntroThreadingDiagnoser](../samples/IntroThreadingDiagnoser.md)]

docs/articles/samples/IntroJitStatsDiagnoser.md

@@ -0,0 +1,31 @@
+---
+uid: BenchmarkDotNet.Samples.IntroJitStatsDiagnoser
+---
+
+## Sample: IntroJitStatsDiagnoser
+
+This diagnoser shows various stats from the JIT compiler that were collected during entire benchmark run (warmup phase and BenchmarkDotNet-generated boilerplate code are included):
+* Amount of JITted methods.
+* Amount of [tiered methods](https://learn.microsoft.com/en-us/dotnet/core/whats-new/dotnet-core-3-0#tiered-compilation).
+* How much memory JIT allocated during the benchmark.
+
+### Restrictions
+
+* Windows only
+
+### Source code
+
+[!code-csharp[IntroJitStatsDiagnoser.cs](../../../samples/BenchmarkDotNet.Samples/IntroJitStatsDiagnoser.cs)]
+
+### Output
+
+| Method |     Mean |    Error |   StdDev | Methods JITted | Methods Tiered | JIT allocated memory |
+|------- |---------:|---------:|---------:|---------------:|---------------:|---------------------:|
+|  Sleep | 15.50 ms | 0.052 ms | 0.048 ms |          1,102 |            214 |            221,736 B |
+
+### Links
+
+* @docs.diagnosers
+* The permanent link to this sample: @BenchmarkDotNet.Samples.IntroJitStatsDiagnoser
+
+---

docs/articles/samples/toc.yml

@@ -60,6 +60,8 @@
   href: IntroInProcess.md
 - name: IntroInProcessWrongEnv
   href: IntroInProcessWrongEnv.md
+- name: IntroJitStatsDiagnoser
+  href: IntroJitStatsDiagnoser.md
 - name: IntroJobBaseline
   href: IntroJobBaseline.md
 - name: IntroJoin

samples/BenchmarkDotNet.Samples/IntroJitStatsDiagnoser.cs

@@ -0,0 +1,12 @@
+using System.Threading;
+using BenchmarkDotNet.Attributes;
+
+namespace BenchmarkDotNet.Samples
+{
+    [Diagnostics.Windows.Configs.JitStatsDiagnoser]
+    public class IntroJitStatsDiagnoser
+    {
+        [Benchmark]
+        public void Sleep() => Thread.Sleep(10);
+    }
+}

src/BenchmarkDotNet.Diagnostics.Windows/Configs/JitStatsDiagnoserAttribute.cs

@@ -0,0 +1,18 @@
+using System;
+using BenchmarkDotNet.Configs;
+using JetBrains.Annotations;
+
+namespace BenchmarkDotNet.Diagnostics.Windows.Configs
+{
+    [PublicAPI]
+    [AttributeUsage(AttributeTargets.Class)]
+    public class JitStatsDiagnoserAttribute : Attribute, IConfigSource
+    {
+        public JitStatsDiagnoserAttribute()
+        {
+            Config = ManualConfig.CreateEmpty().AddDiagnoser(new JitStatsDiagnoser());
+        }
+
+        public IConfig Config { get; }
+    }
+}