In configuration settings of the V8 JS engine was added two new properties: AddPerformanceObject (default false) and SetTimerResolution (default false)

Author: Taritsyn

src/JavaScriptEngineSwitcher.V8/JavaScriptEngineSwitcher.V8.csproj

@@ -21,7 +21,8 @@
     <PackageIconFullPath>../../Icons/JavaScriptEngineSwitcher_V8_Logo128x128.png</PackageIconFullPath>
     <Description>JavaScriptEngineSwitcher.V8 contains a `V8JsEngine` adapter (wrapper for the Microsoft ClearScript.V8).</Description>
     <PackageTags>$(PackageCommonTags);V8;ClearScript</PackageTags>
-    <PackageReleaseNotes>Microsoft ClearScript.V8 was updated to version 7.4.5.</PackageReleaseNotes>
+    <PackageReleaseNotes>1. Microsoft ClearScript.V8 was updated to version 7.4.5;
+2. In configuration settings of the V8 JS engine was added two new properties: `AddPerformanceObject` (default `false`) and `SetTimerResolution` (default `false`).</PackageReleaseNotes>
   </PropertyGroup>
 
   <ItemGroup>

src/JavaScriptEngineSwitcher.V8/V8JsEngine.cs

@@ -107,6 +107,10 @@ public V8JsEngine(V8Settings settings)
 			};
 
 			OriginalEngineFlags flags = OriginalEngineFlags.None;
+			if (v8Settings.AddPerformanceObject)
+			{
+				flags |= OriginalEngineFlags.AddPerformanceObject;
+			}
 			if (v8Settings.AwaitDebuggerAndPauseOnStart)
 			{
 				flags |= OriginalEngineFlags.AwaitDebuggerAndPauseOnStart;
@@ -123,6 +127,10 @@ public V8JsEngine(V8Settings settings)
 			{
 				flags |= OriginalEngineFlags.DisableGlobalMembers;
 			}
+			if (v8Settings.SetTimerResolution)
+			{
+				flags |= OriginalEngineFlags.SetTimerResolution;
+			}
 
 			int debugPort = v8Settings.DebugPort;
 

src/JavaScriptEngineSwitcher.V8/V8Settings.cs

@@ -7,6 +7,20 @@ namespace JavaScriptEngineSwitcher.V8
 	/// </summary>
 	public sealed class V8Settings
 	{
+		/// <summary>
+		/// Gets or sets a flag for whether to add the
+		/// <c><see href="https://microsoft.github.io/ClearScript/2024/03/21/performance-api.html">Performance</see></c>
+		/// object to the script engine's global namespace
+		/// </summary>
+		/// <remarks>
+		/// This object provides a set of low-level native facilities for performance-sensitive scripts.
+		/// </remarks>
+		public bool AddPerformanceObject
+		{
+			get;
+			set;
+		}
+
 		/// <summary>
 		/// Gets or sets a flag for whether to allow the usage of reflection API in the script code
 		/// </summary>
@@ -217,12 +231,28 @@ public UIntPtr MaxStackUsage
 			set;
 		}
 
+		/// <summary>
+		/// Gets or sets a flag for whether to set native timers to the highest available resolution
+		/// while the current script engine's instance is active
+		/// </summary>
+		/// <remarks>
+		/// This property is ignored if <c><see cref="AddPerformanceObject"/></c> property is <c>false</c>.
+		/// It is only a hint and may be ignored on some systems. On platforms that support it, this
+		/// property can degrade overall system performance or power efficiency, so caution is recommended.
+		/// </remarks>
+		public bool SetTimerResolution
+		{
+			get;
+			set;
+		}
+
 
 		/// <summary>
 		/// Constructs an instance of the V8 settings
 		/// </summary>
 		public V8Settings()
 		{
+			AddPerformanceObject = false;
 			AllowReflection = false;
 			AwaitDebuggerAndPauseOnStart = false;
 			DebugPort = 9222;
@@ -237,6 +267,7 @@ public V8Settings()
 			MaxNewSpaceSize = 0;
 			MaxOldSpaceSize = 0;
 			MaxStackUsage = UIntPtr.Zero;
+			SetTimerResolution = false;
 		}
 	}
 }

src/JavaScriptEngineSwitcher.V8/readme.txt

@@ -31,7 +31,10 @@
    =============
    RELEASE NOTES
    =============
-   Microsoft ClearScript.V8 was updated to version 7.4.5.
+   1. Microsoft ClearScript.V8 was updated to version 7.4.5;
+   2. In configuration settings of the V8 JS engine was added two new properties:
+      `AddPerformanceObject` (default `false`) and `SetTimerResolution` (default
+      `false`).
 
    =============
    DOCUMENTATION