In IJsEngine interface was added SupportsGarbageCollection property and CollectGarbage method

Author: Taritsyn

src/JavaScriptEngineSwitcher.ChakraCore/ChakraCoreJsEngine.cs

@@ -78,6 +78,14 @@ public override string Version
 			get { return EngineVersion; }
 		}
 
+		/// <summary>
+		/// Gets a value that indicates if the JS engine supports garbage collection
+		/// </summary>
+		public override bool SupportsGarbageCollection
+		{
+			get { return true; }
+		}
+
 
 		/// <summary>
 		/// Static constructor
@@ -1010,6 +1018,14 @@ protected override void InnerEmbedHostType(string itemName, Type type)
 			});
 		}
 
+		protected override void InnerCollectGarbage()
+		{
+			lock (_executionSynchronizer)
+			{
+				_jsRuntime.CollectGarbage();
+			}
+		}
+
 		#endregion
 
 		#region IDisposable implementation

src/JavaScriptEngineSwitcher.Core/IJsEngine.cs

@@ -25,6 +25,14 @@ string Version
 			get;
 		}
 
+		/// <summary>
+		/// Gets a value that indicates if the JS engine supports garbage collection
+		/// </summary>
+		bool SupportsGarbageCollection
+		{
+			get;
+		}
+
 
 		/// <summary>
 		/// Evaluates an expression
@@ -138,5 +146,10 @@ string Version
 		/// methods are bound to the type's static members.
 		/// </remarks>
 		void EmbedHostType(string itemName, Type type);
+
+		/// <summary>
+		/// Performs a full garbage collection
+		/// </summary>
+		void CollectGarbage();
 	}
 }

src/JavaScriptEngineSwitcher.Core/JsEngineBase.cs

@@ -57,6 +57,11 @@ protected virtual void InnerEmbedHostType(string itemName, Type type)
 			throw new NotImplementedException();
 		}
 
+		protected virtual void InnerCollectGarbage()
+		{
+			throw new NotImplementedException();
+		}
+
 		#region IJsEngine implementation
 
 		public abstract string Name
@@ -69,6 +74,14 @@ public abstract string Version
 			get;
 		}
 
+		public virtual bool SupportsGarbageCollection
+		{
+			get
+			{
+				throw new NotImplementedException();
+			}
+		}
+
 
 		public virtual object Evaluate(string expression)
 		{
@@ -440,6 +453,13 @@ public virtual void EmbedHostType(string itemName, Type type)
 			InnerEmbedHostType(itemName, type);
 		}
 
+		public virtual void CollectGarbage()
+		{
+			VerifyNotDisposed();
+
+			InnerCollectGarbage();
+		}
+
 		#endregion
 
 		#region IDisposable implementation

src/JavaScriptEngineSwitcher.Jint/JintJsEngine.cs

@@ -59,6 +59,14 @@ public override string Version
 			get { return EngineVersion; }
 		}
 
+		/// <summary>
+		/// Gets a value that indicates if the JS engine supports garbage collection
+		/// </summary>
+		public override bool SupportsGarbageCollection
+		{
+			get { return false; }
+		}
+
 
 		/// <summary>
 		/// Constructs a instance of adapter for the Jint JS engine
@@ -477,6 +485,11 @@ protected override void InnerEmbedHostType(string itemName, Type type)
 			}
 		}
 
+		protected override void InnerCollectGarbage()
+		{
+			throw new NotImplementedException();
+		}
+
 		#endregion
 
 		#region IDisposable implementation

src/JavaScriptEngineSwitcher.Jurassic/JurassicJsEngine.cs

@@ -56,6 +56,14 @@ public override string Version
 			get { return EngineVersion; }
 		}
 
+		/// <summary>
+		/// Gets a value that indicates if the JS engine supports garbage collection
+		/// </summary>
+		public override bool SupportsGarbageCollection
+		{
+			get { return false; }
+		}
+
 
 		/// <summary>
 		/// Constructs a instance of adapter for the Jurassic JS engine
@@ -385,6 +393,11 @@ public override void ExecuteFile(string path, Encoding encoding = null)
 			}
 		}
 
+		protected override void InnerCollectGarbage()
+		{
+			throw new NotImplementedException();
+		}
+
 		#endregion
 
 		#region IDisposable implementation

src/JavaScriptEngineSwitcher.Msie/MsieJsEngine.cs

@@ -50,6 +50,14 @@ public override string Version
 			get { return _engineVersion; }
 		}
 
+		/// <summary>
+		/// Gets a value that indicates if the JS engine supports garbage collection
+		/// </summary>
+		public override bool SupportsGarbageCollection
+		{
+			get { return true; }
+		}
+
 
 		/// <summary>
 		/// Constructs a instance of adapter for the MSIE JS engine
@@ -308,6 +316,11 @@ protected override void InnerEmbedHostType(string itemName, Type type)
 			}
 		}
 
+		protected override void InnerCollectGarbage()
+		{
+			_jsEngine.CollectGarbage();
+		}
+
 		#endregion
 
 		#region IDisposable implementation

src/JavaScriptEngineSwitcher.V8/V8JsEngine.cs

@@ -72,6 +72,14 @@ public override string Version
 			get { return EngineVersion; }
 		}
 
+		/// <summary>
+		/// Gets a value that indicates if the JS engine supports garbage collection
+		/// </summary>
+		public override bool SupportsGarbageCollection
+		{
+			get { return true; }
+		}
+
 
 		/// <summary>
 		/// Static constructor
@@ -429,6 +437,14 @@ protected override void InnerEmbedHostType(string itemName, Type type)
 			}
 		}
 
+		protected override void InnerCollectGarbage()
+		{
+			lock (_executionSynchronizer)
+			{
+				_jsEngine.CollectGarbage(true);
+			}
+		}
+
 		#endregion
 
 		#region IDisposable implementation

test/JavaScriptEngineSwitcher.Tests/CommonTestsBase.cs

@@ -765,5 +765,26 @@ public virtual void RemovingVariableIsCorrect()
 		}
 
 		#endregion
+
+		#region Garbage collection
+
+		[Fact]
+		public virtual void GarbageCollectionIsCorrect()
+		{
+			// Arrange
+			const string input = @"arr = []; for (i = 0; i < 1000000; i++) { arr.push(arr); }";
+
+			// Act
+			using (var jsEngine = CreateJsEngine())
+			{
+				jsEngine.Execute(input);
+				if (jsEngine.SupportsGarbageCollection)
+				{
+					jsEngine.CollectGarbage();
+				}
+			}
+		}
+
+		#endregion
 	}
 }