removed cloning of CriticalFinalizerObjects (usually it is SafeHandle). Clone of handles cause unpredictable results

Author: force-net

DeepCloner.Tests/SystemTypesSpec.cs

@@ -3,8 +3,11 @@
 using System.IO;
 using System.Reflection;
 using System.Runtime.InteropServices;
+using System.Security.Cryptography.X509Certificates;
 using System.Text;
 
+using Microsoft.Win32.SafeHandles;
+
 using NUnit.Framework;
 
 namespace Force.DeepCloner.Tests
@@ -50,9 +53,11 @@ public void Type_With_Native_Resource_Should_Be_Cloned()
 				Console.WriteLine(f2.GetValue(f.GetValue(writer.BaseStream)));
 				Console.WriteLine(f2.GetValue(f.GetValue(cloned.BaseStream)));
 				writer.Close();
-				cloned.Close();
-				// this was a bug, we should not throw there
-				// Assert.Throws<ObjectDisposedException>(cloned.Close);
+				// cloned.Close();
+				// not a bug anymore, this is feature: we don't duplicate handles, because it can cause unpredictable results
+				// ~~this was a bug, we should not throw there~~
+
+				Assert.Throws<ObjectDisposedException>(cloned.Close);
 				var res = File.ReadAllText(fileName);
 				Assert.That(res, Is.EqualTo("123"));
 			}
@@ -114,5 +119,40 @@ public void Events_Should_Be_Cloned()
 			Assert.That(summ[0], Is.EqualTo(2)); // nothing to increment
 			Assert.That(clone.Call(1), Is.EqualTo(2));
 		}
+
+		private const string CertData =
+			@"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";
+
+		[Test(Description = "Without special handling it causes exception on destruction due native resources usage")]
+		public void Certificate_Should_Be_Cloned()
+		{
+			var cert = new X509Certificate2(Convert.FromBase64String(CertData), "1");
+			cert.DeepClone();
+			cert.DeepClone();
+			GC.Collect();
+			GC.WaitForFullGCComplete();
+		}
+
+		[Test(Description = "Without special handling it causes exception on destruction due native resources usage")]
+		public void ObjectHandle_Should_Be_Cloned()
+		{
+			var cert = new X509Certificate2(Convert.FromBase64String(CertData), "1");
+			var handle = (SafeHandleZeroOrMinusOneIsInvalid)
+				cert.GetType().GetField("m_safeCertContext", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(cert);
+			handle.DeepClone();
+			handle.DeepClone();
+			GC.Collect();
+			GC.WaitForFullGCComplete();
+		}
+
+		[Test(Description = "Without special handling it causes exception on destruction due native resources usage")]
+		public void Certificate_Should_Be_Shallow_Cloned()
+		{
+			var cert = new X509Certificate2(Convert.FromBase64String(CertData), "1");
+			cert.ShallowClone();
+			cert.ShallowClone();
+			GC.Collect();
+			GC.WaitForFullGCComplete();
+		}
 	}
 }

DeepCloner.nuspec

@@ -3,7 +3,7 @@
   <metadata>
     <id>DeepCloner</id>
     <title>DeepCloner</title>
-    <version>0.9.2</version>
+    <version>0.9.3</version>
     <authors>force</authors>
     <owners>force</owners>
     <licenseUrl>https://github.com/force-net/DeepCloner/blob/develop/LICENSE</licenseUrl>
@@ -12,10 +12,7 @@
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
     <description>Small Library for fast deep or shallow cloning .NET objects. It allows to copy everything and has a lot of performance tricks for fast copying.</description>
     <releaseNotes>
-Seriously improved cloning of simple object (constructor analyzing + reference counting)
-Fixed small issue with possible multiple copying of same fields in object
-Safe variant now correctly clones readonly fields
-Fixed small issue with cloning primitive types casted as an object
+Changed behaviour of cloning resources with handles. Now, they don't clone (same object is returned) due unpredictable clone results. 
     </releaseNotes>
     <copyright>Copyright by Force 2016</copyright>
     <tags>.NET shallow deep clone DeepClone fast</tags>

DeepCloner/Helpers/DeepClonerExprGenerator.cs

@@ -9,6 +9,8 @@ internal static class DeepClonerExprGenerator
 	{
 		internal static object GenerateClonerInternal(Type realType, bool asObject)
 		{
+			if (DeepClonerSafeTypes.IsTypeSafe(realType, null)) return null;
+
 			return GenerateProcessMethod(realType, asObject && realType.IsValueType);
 		}
 

DeepCloner/Helpers/DeepClonerSafeTypes.cs

@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using System.Runtime.ConstrainedExecution;
 
 namespace Force.DeepCloner.Helpers
 {
@@ -40,6 +41,13 @@ internal static bool IsTypeSafe(Type type, HashSet<Type> processingTypes)
 				return true;
 			}
 
+			// this types are serious native resources, it is better not to clone it
+			if (type.IsSubclassOf(typeof(CriticalFinalizerObject)))
+			{
+				KnownTypes.TryAdd(type, true);
+				return true;
+			}
+
 			// classes are always unsafe (we should copy it fully to count references)
 			if (!type.IsValueType)
 			{

DeepCloner/Helpers/ShallowObjectCloner.cs

@@ -2,6 +2,7 @@
 using System.Linq.Expressions;
 using System.Reflection;
 using System.Reflection.Emit;
+using System.Runtime.ConstrainedExecution;
 
 namespace Force.DeepCloner.Helpers
 {
@@ -23,6 +24,8 @@ public static object CloneObject(object obj)
 		{
 			if (obj == null) return null;
 			if (obj is string) return obj;
+			// do not clone such native-resource bounded types!
+			if (obj is CriticalFinalizerObject) return obj;
 			return _instance.DoCloneObject(obj);
 		}
 

DeepCloner/Properties/AssemblyInfo.cs

@@ -32,8 +32,8 @@
 // by using the '*' as shown below:
 
 [assembly: AssemblyVersion("0.8.0.0")] // change this value only when api is changing
-[assembly: AssemblyFileVersion("0.9.2.0")]
-[assembly: AssemblyInformationalVersion("0.9.2.0")]
+[assembly: AssemblyFileVersion("0.9.3.0")]
+[assembly: AssemblyInformationalVersion("0.9.3.0")]
 
 #if !DEBUG
 [assembly: AssemblyKeyFileAttribute("..\\public.snk")]