EventCounters via ETW

CounterPayload.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Collections.Generic;

namespace Microsoft.Diagnostics.Tools.Counters
{
    public interface ICounterPayload
    {
        string GetName();
        string GetValue();
        string GetDisplay();
    }

    class CounterPayload : ICounterPayload
    {
        public string m_Name;
        public string m_Value;
        public string m_DisplayName;
        public CounterPayload(IDictionary<string, object> payloadFields)
        {
            m_Name = payloadFields["Name"].ToString();
            m_Value = payloadFields["Mean"].ToString();
            m_DisplayName = payloadFields["DisplayName"].ToString();
        }

        public string GetName() => m_Name;
        public string GetValue() => m_Value;
        public string GetDisplay() => m_DisplayName;
    }

    class IncrementingCounterPayload : ICounterPayload
    {
        public string m_Name;
        public string m_Value;
        public string m_DisplayName;
        public string m_DisplayRateTimeScale;
        public IncrementingCounterPayload(IDictionary<string, object> payloadFields)
        {
            m_Name = payloadFields["Name"].ToString();
            m_Value = payloadFields["Increment"].ToString();
            m_DisplayName = payloadFields["DisplayName"].ToString();
            m_DisplayRateTimeScale = TimeSpan.Parse(payloadFields["DisplayRateTimeScale"].ToString()).ToString("%s' sec'");
        }

        public string GetName() => m_Name;
        public string GetValue() => m_Value;
        public string GetDisplay() => $"{m_DisplayName} / {m_DisplayRateTimeScale}";
    }
}

EtwMetrics.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net5.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Diagnostics.Tracing.TraceEvent" Version="2.0.62" />
  </ItemGroup>

</Project>

Program.cs

using System;
using System.Collections.Generic;
using Microsoft.Diagnostics.Tools.Counters;
using Microsoft.Diagnostics.Tracing;
using Microsoft.Diagnostics.Tracing.Session;

var pids = new List<int> { 2412 };

using var session = new TraceEventSession("metrics");
Console.CancelKeyPress += 
    (object s, ConsoleCancelEventArgs args) => session.Stop();

var options = new TraceEventProviderOptions();
options.ProcessIDFilter = pids;
options.AddArgument("EventCounterIntervalSec", "1");

session.EnableProvider("System.Runtime", TraceEventLevel.Always, ulong.MaxValue, options);
session.Source.Dynamic.AddCallbackForProviderEvent("System.Runtime", "EventCounters", (obj) =>
{
    IDictionary<string, object> payloadFields = (IDictionary<string, object>)(obj.PayloadValue(0));
    ICounterPayload payload;
    if (payloadFields.ContainsKey("CounterType"))
    {
        payload = payloadFields["CounterType"].Equals("Sum") ? (ICounterPayload)new IncrementingCounterPayload(payloadFields) : (ICounterPayload)new CounterPayload(payloadFields);
    }
    else
    {
        payload = payloadFields.Count == 6 ? (ICounterPayload)new IncrementingCounterPayload(payloadFields) : (ICounterPayload)new CounterPayload(payloadFields);
    }
    Console.WriteLine($"{payload.GetDisplay()}\t{payload.GetValue()}");
});

session.Source.Process();