Optimize GC and performance for MonoPInvokeCallback.

Assets/Cryville/Common/Unity/ScopedThreadAttacherInjector.cs

@@ -0,0 +1,50 @@
+#if UNITY_EDITOR
+using System;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
+using UnityEditor;
+
+namespace Cryville.Common.Unity {
+	[InitializeOnLoad]
+	public class ScopedThreadAttacherInjector {
+		static readonly Encoding _encoding = new UTF8Encoding(false, true);
+		static string _filePath;
+		static string _oldSrc;
+
+		static ScopedThreadAttacherInjector() {
+			BuildPlayerWindow.RegisterBuildPlayerHandler(opt => HandlePlayerBuild(opt));
+		}
+
+		static void HandlePlayerBuild(BuildPlayerOptions opt) {
+			try {
+				OnPreprocessBuild();
+				BuildPlayerWindow.DefaultBuildMethods.BuildPlayer(opt);
+			}
+			finally {
+				OnPostprocessBuild();
+			}
+		}
+
+		static void OnPreprocessBuild() {
+			var il2cppRoot = Environment.GetEnvironmentVariable("UNITY_IL2CPP_PATH");
+			if (string.IsNullOrEmpty(il2cppRoot)) {
+				_filePath = string.Empty;
+				return;
+			}
+			_filePath = Path.Combine(il2cppRoot, "libil2cpp", "vm", "ScopedThreadAttacher.cpp");
+			if (!File.Exists(_filePath)) {
+				_filePath = string.Empty;
+				return;
+			}
+			_oldSrc = File.ReadAllText(_filePath, _encoding);
+			File.WriteAllText(_filePath, Regex.Replace(_oldSrc, @"~\s*?ScopedThreadAttacher\s*?\(\s*?\)\s*?\{.*\}", "~ScopedThreadAttacher(){}", RegexOptions.Singleline), _encoding);
+		}
+
+		static void OnPostprocessBuild() {
+			if (string.IsNullOrEmpty(_filePath)) return;
+			File.WriteAllText(_filePath, _oldSrc, _encoding);
+		}
+	}
+}
+#endif

Assets/Cryville/Common/Unity/ScopedThreadAttacherInjector.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 2322d8e9250e9e6469826361223dfdda
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: