Add ChromeTracingProfileWriter

to output profiling events in 'chrome://tracing' JSON format, which can be analyzed by ui.perfetto.dev and other tools

sources/core/Stride.Core/Diagnostics/ChromeTracingProfileWriter.cs

@@ -0,0 +1,101 @@
+// Copyright (c) .NET Foundation and Contributors (https://dotnetfoundation.org/ & https://stride3d.net)
+// Distributed under the MIT license. See the LICENSE.md file in the project root for more information.
+using System.Diagnostics;
+using System.IO;
+using System.Text.Json.Nodes;
+using System.Text.Json;
+using System.Threading.Channels;
+using System.Threading.Tasks;
+
+namespace Stride.Core.Diagnostics
+{
+    public class ChromeTracingProfileWriter
+    {
+        public void Start(string outputPath, bool indentOutput = false)
+        {
+            eventReader = Profiler.Subscribe();
+            writerTask = Task.Run(async () =>
+            {
+                var pid = Process.GetCurrentProcess().Id;
+
+                using FileStream fs = File.Create(outputPath);
+                using var writer = new Utf8JsonWriter(fs, options: new JsonWriterOptions { Indented = indentOutput });
+
+                JsonObject root = new JsonObject();
+
+                writer.WriteStartObject();
+                writer.WriteStartArray("traceEvents");
+  
+                writer.WriteStartObject();
+                writer.WriteString("name", "thread_name");
+                writer.WriteString("ph", "M");
+                writer.WriteNumber("pid", pid);
+                writer.WriteNumber("tid", int.MaxValue);
+                writer.WriteStartObject("args");
+                writer.WriteString("name", "GPU");
+                writer.WriteEndObject();
+                writer.WriteEndObject();
+                writer.WriteStartObject();
+                writer.WriteString("name", "thread_sort_index");
+                writer.WriteString("ph", "M");
+                writer.WriteNumber("pid", pid);
+                writer.WriteNumber("tid", int.MaxValue);
+                writer.WriteStartObject("args");
+                writer.WriteNumber("sort_index", int.MaxValue);
+                writer.WriteEndObject();
+                writer.WriteEndObject();
+
+                await foreach (var e in eventReader.ReadAllAsync())
+                {                    
+                    //gc scopes currently start at negative timestamps and should be filtered out,
+                    //because they don't represent durations.
+                    if (e.TimeStamp.Ticks < 0)
+                        continue;
+
+                    double startTimeInMicroseconds = e.TimeStamp.TotalMilliseconds * 1000.0;
+                    double durationInMicroseconds = e.ElapsedTime.TotalMilliseconds * 1000.0;
+
+                    Debug.Assert(durationInMicroseconds >= 0);
+
+                    writer.WriteStartObject();
+                    writer.WriteString("name", e.Key.Name);
+                    if (e.Key.Parent != null)
+                        writer.WriteString("cat", e.Key.Parent.Name);
+                    writer.WriteString("ph", "X");
+                    writer.WriteNumber("ts", startTimeInMicroseconds);
+                    writer.WriteNumber("dur", durationInMicroseconds);
+                    writer.WriteNumber("tid", e.ThreadId>=0?e.ThreadId: int.MaxValue);
+                    writer.WriteNumber("pid", pid);
+                    if (e.Attributes.Count > 0)
+                    {
+                        writer.WriteStartObject("args");
+                        foreach (var (k,v) in e.Attributes)
+                        {
+                            writer.WriteString(k, v.ToString());
+                        }                        
+                        writer.WriteEndObject();
+                    }
+                    writer.WriteEndObject();
+                }
+
+                writer.WriteEndArray();
+                writer.WriteEndObject();
+                writer.Flush();
+            });
+        }
+
+        public void Stop()
+        {
+            if (eventReader != null)
+            {
+                Profiler.Unsubscribe(eventReader);
+                writerTask?.Wait();
+            }
+        }
+#nullable enable
+        ChannelReader<ProfilingEvent>? eventReader;
+        Task? writerTask;
+#nullable disable
+    }
+
+}