Prepare sampler for TraceEvent parsing

Author: xoofx

src/Ultra.Core/DiagnosticPortSession.cs

@@ -112,7 +112,7 @@ public async Task StartProfiling(CancellationToken token)
                 _nettraceFileStream = new FileStream(_nettraceFilePath, FileMode.Create, FileAccess.Write, FileShare.Read, 65536, FileOptions.Asynchronous);
 
                 long keywords = -1;
-                var providerName = UltraSamplerParser.Name;
+                var providerName = UltraSamplerConstants.Name;
                 var level = EventLevel.Verbose;
 
                 if (!_sampler)

src/Ultra.Core/Ultra.Core.csproj

@@ -27,7 +27,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Compile Include="..\Ultra.Sampler\UltraSamplerParser.cs" Link="UltraSamplerParser.cs" />
+    <Compile Include="..\Ultra.Sampler\UltraSamplerConstants.cs" Link="UltraSamplerConstants.cs" />
   </ItemGroup>
 
   <ItemGroup>

src/Ultra.Sampler/MacOS/MacOSUltraSampler.cs

@@ -170,7 +170,7 @@ private void NotifyPendingNativeModuleEvents()
             for(; _nextModuleEventIndexToLog < events.Length; _nextModuleEventIndexToLog++)
             {
                 var evt = events[_nextModuleEventIndexToLog];
-                UltraSamplerSource.Log.OnNativeModuleEvent((int)evt.Kind, evt.LoadAddress, evt.Size, evt.Path, evt.TimestampUtc);
+                UltraSamplerSource.Log.OnNativeModuleEvent((int)evt.Kind, evt.LoadAddress, evt.Size, evt.TimestampUtc, evt.Path?.Length ?? 0, evt.Path);
             }
         }
     }
@@ -293,7 +293,7 @@ private static unsafe void Sample(MacOS.MacOSLibSystem.mach_port_t rootTask, ulo
 
                     //Console.WriteLine($"sp: 0x{armThreadState.__sp:X8}, fp: 0x{armThreadState.__fp:X8}, lr: 0x{armThreadState.__lr:X8}");
                     int frameCount = WalkNativeCallStack(armThreadState.__sp, armThreadState.__fp, armThreadState.__lr, pFrames);
-                    nativeCallstack(threadInfo.thread_id, (ulong)pFrames, frameCount);
+                    nativeCallstack(threadInfo.thread_id, frameCount, (ulong)pFrames);
                 }
                 finally
                 {

src/Ultra.Sampler/MacOS/NativeCallstackDelegate.cs

@@ -4,4 +4,4 @@
 
 namespace Ultra.Sampler.MacOS;
 
-internal unsafe delegate void NativeCallstackDelegate(ulong threadId, ulong pFrames, int frameCount);
+internal unsafe delegate void NativeCallstackDelegate(ulong threadId, int frameCount, ulong pFrames);

src/Ultra.Sampler/UltraSamplerConstants.cs

@@ -0,0 +1,19 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// Licensed under the BSD-Clause 2 license.
+// See license.txt file in the project root for full license information.
+
+namespace Ultra.Sampler;
+
+internal static class UltraSamplerConstants
+{
+    public const string Name = "Ultra-Sampler";
+
+    public const string IdAsString = "04E4DCBF-494F-4A77-B55E-F5C041A92F56";
+
+    public static readonly Guid Id = new(IdAsString);
+
+    public const int NativeCallStackEvent = 1;
+
+    public const int NativeModuleEvent = 2;
+
+}

src/Ultra.Sampler/UltraSamplerParser.cs

@@ -4,10 +4,11 @@
 
 using System.Diagnostics.CodeAnalysis;
 using System.Diagnostics.Tracing;
+using System.Runtime.CompilerServices;
 
 namespace Ultra.Sampler;
 
-[EventSource(Name = UltraSamplerParser.Name, Guid = UltraSamplerParser.IdAsString)]
+[EventSource(Name = UltraSamplerConstants.Name, Guid = UltraSamplerConstants.IdAsString)]
 internal sealed class UltraSamplerSource : EventSource
 {
     public static readonly UltraSamplerSource Log = new();
@@ -16,39 +17,47 @@ private UltraSamplerSource()
     {
     }
 
-    [Event(UltraSamplerParser.NativeCallStackEvent, Level = EventLevel.Informational)]
+    [Event(UltraSamplerConstants.NativeCallStackEvent, Level = EventLevel.Informational)]
     [UnconditionalSuppressMessage("Trimming", "IL2026:Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code", Justification = "<Pending>")]
-    public unsafe void OnNativeCallstack(ulong threadId, ulong pFrames, int count)
+    public unsafe void OnNativeCallstack(ulong threadId, int frameCount, ulong frames) // frames is last to allow perfview to visualize previous fixed size arguments and also, it is an ulong otherwise the EventSource will silently fail to register!
     {
-        EventData3 evt = default;
-        evt.Data1.DataPointer = (nint)(void*)&threadId;
-        evt.Data1.Size = sizeof(ulong);
-        evt.Data2.DataPointer = (nint)pFrames;
-        evt.Data2.Size = count * sizeof(ulong);
-        evt.Data3.DataPointer = (int) &count;
-        evt.Data3.Size = sizeof(int);
-        WriteEventCore(UltraSamplerParser.NativeCallStackEvent, 3, &evt.Data1);
+        var evt = stackalloc EventData[3];
+        evt[0].DataPointer = (nint)(void*)&threadId;
+        evt[0].Size = sizeof(ulong);
+        evt[1].DataPointer = (int) &frameCount;
+        evt[1].Size = sizeof(int);
+        evt[2].DataPointer = (nint)frames;
+        evt[2].Size = frameCount * sizeof(ulong);
+        WriteEventCore(UltraSamplerConstants.NativeCallStackEvent, 3, evt);
     }
 
-    [Event(UltraSamplerParser.NativeModuleEvent, Level = EventLevel.Informational)]
+    [Event(UltraSamplerConstants.NativeModuleEvent, Level = EventLevel.Informational)]
     [UnconditionalSuppressMessage("Trimming", "IL2026:Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code", Justification = "<Pending>")]
-    public unsafe void OnNativeModuleEvent(int nativeModuleEventKind, ulong loadAddress, ulong size, byte[]? modulePathUtf8, DateTime timestampUtc)
+    [SkipLocalsInit]
+    public unsafe void OnNativeModuleEvent(int nativeModuleEventKind, ulong loadAddress, ulong size, DateTime timestampUtc, int modulePathUtf8Length, byte[]? modulePathUtf8) // byte[] is last to allow perfview to visualize previous fixed size arguments
     {
-        EventData5 evt = default;
-        evt.Data1.DataPointer = (nint)(void*)&nativeModuleEventKind;
-        evt.Data1.Size = sizeof(int);
-        evt.Data2.DataPointer = (nint)(void*)&loadAddress;
-        evt.Data2.Size = sizeof(ulong);
-        evt.Data3.DataPointer = (nint)(void*)&size;
-        evt.Data3.Size = sizeof(ulong);
+        var evt = stackalloc EventData[6];
+        evt[0].DataPointer = (nint)(void*)&nativeModuleEventKind;
+        evt[0].Size = sizeof(int);
+        evt[1].DataPointer = (nint)(void*)&loadAddress;
+        evt[1].Size = sizeof(ulong);
+        evt[2].DataPointer = (nint)(void*)&size;
+        evt[2].Size = sizeof(ulong);
+        var utcFileTime = timestampUtc.ToFileTimeUtc();
+        evt[3].DataPointer = (nint)(void*)&utcFileTime;
+        evt[3].Size = sizeof(long);
         fixed (byte* evtPathPtr = modulePathUtf8)
         {
-            evt.Data4.DataPointer = (nint)evtPathPtr;
-            evt.Data4.Size = modulePathUtf8?.Length ?? 0;
-            var utcFileTime = timestampUtc.ToFileTimeUtc();
-            evt.Data5.DataPointer = (nint)(void*)&utcFileTime;
-            evt.Data5.Size = sizeof(long);
-            WriteEventCore(UltraSamplerParser.NativeModuleEvent, 5, &evt.Data1);
+            evt[4].DataPointer = (nint)(void*)&modulePathUtf8Length;
+            evt[4].Size = sizeof(int);
+
+            if (modulePathUtf8Length > 0)
+            {
+                evt[5].DataPointer = (nint)evtPathPtr;
+                evt[5].Size = modulePathUtf8Length;
+            }
+            
+            WriteEventCore(UltraSamplerConstants.NativeModuleEvent, modulePathUtf8Length > 0 ? 5 : 4, evt);
         }
     }
 
@@ -67,26 +76,4 @@ protected override void OnEventCommand(EventCommandEventArgs command)
             Thread.Sleep(100);
         }
     }
-
-    private struct EventData3
-    {
-        public EventData Data1;
-
-        public EventData Data2;
-
-        public EventData Data3;
-    }
-
-    private struct EventData5
-    {
-        public EventData Data1;
-
-        public EventData Data2;
-
-        public EventData Data3;
-
-        public EventData Data4;
-
-        public EventData Data5;
-    }
 }