Rename AggregateTypeResolveContext to CompositeTypeResolveContext.

Rename DotNetName to ReflectionName.
Added ReflectionName-parser to ReflectionHelper.
Move the ReaderWriterLock synchronization from TypeStorage to SimpleProjectContent.
Added some documentation to the README.

ICSharpCode.NRefactory.Tests/TypeSystem/CecilLoaderTests.cs

@@ -58,7 +58,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		{
 			ITypeDefinition c = Mscorlib.GetClass(typeof(IntPtr));
 			IMethod toPointer = c.Methods.Single(p => p.Name == "ToPointer");
-			Assert.AreEqual("System.Void*", toPointer.ReturnType.Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.Void*", toPointer.ReturnType.Resolve(ctx).ReflectionName);
 			Assert.IsInstanceOf(typeof(PointerType), toPointer.ReturnType.Resolve(ctx));
 			Assert.AreEqual("System.Void", ((PointerType)toPointer.ReturnType.Resolve(ctx)).ElementType.FullName);
 		}
@@ -107,7 +107,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			ITypeDefinition c = Mscorlib.GetClass(typeof(Environment.SpecialFolder));
 			Assert.IsNotNull(c, "c is null");
 			Assert.AreEqual("System.Environment.SpecialFolder", c.FullName);
-			Assert.AreEqual("System.Environment+SpecialFolder", c.DotNetName);
+			Assert.AreEqual("System.Environment+SpecialFolder", c.ReflectionName);
 		}
 		
 		[Test]
@@ -135,7 +135,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			var dictionaryRT = new ParameterizedType(dictionary, new[] { Mscorlib.GetClass(typeof(string)), Mscorlib.GetClass(typeof(int)) });
 			IProperty valueProperty = dictionaryRT.GetProperties(ctx).Single(p => p.Name == "Values");
 			IType parameterizedValueCollection = valueProperty.ReturnType.Resolve(ctx);
-			Assert.AreEqual("System.Collections.Generic.Dictionary`2+ValueCollection[[System.String],[System.Int32]]", parameterizedValueCollection.DotNetName);
+			Assert.AreEqual("System.Collections.Generic.Dictionary`2+ValueCollection[[System.String],[System.Int32]]", parameterizedValueCollection.ReflectionName);
 			Assert.AreSame(valueCollection, parameterizedValueCollection.GetDefinition());
 		}
 		

ICSharpCode.NRefactory.Tests/TypeSystem/GetAllBaseTypesTest.cs

@@ -18,12 +18,12 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		
 		IType[] GetAllBaseTypes(Type type)
 		{
-			return type.ToTypeReference().Resolve(context).GetAllBaseTypes(context).OrderBy(t => t.DotNetName).ToArray();
+			return type.ToTypeReference().Resolve(context).GetAllBaseTypes(context).OrderBy(t => t.ReflectionName).ToArray();
 		}
 		
 		IType[] GetTypes(params Type[] types)
 		{
-			return types.Select(t => t.ToTypeReference().Resolve(context)).OrderBy(t => t.DotNetName).ToArray();;
+			return types.Select(t => t.ToTypeReference().Resolve(context)).OrderBy(t => t.ReflectionName).ToArray();;
 		}
 		
 		[Test]
@@ -85,7 +85,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 				mscorlib.GetClass(typeof(object))
 			};
 			Assert.AreEqual(expected,
-			                c.GetAllBaseTypes(context).OrderBy(t => t.DotNetName).ToArray());
+			                c.GetAllBaseTypes(context).OrderBy(t => t.ReflectionName).ToArray());
 		}
 		
 		[Test]
@@ -103,7 +103,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 				mscorlib.GetClass(typeof(ValueType))
 			};
 			Assert.AreEqual(expected,
-			                s.GetAllBaseTypes(context).OrderBy(t => t.DotNetName).ToArray());
+			                s.GetAllBaseTypes(context).OrderBy(t => t.ReflectionName).ToArray());
 		}
 	}
 }

ICSharpCode.NRefactory.Tests/TypeSystem/ReflectionHelperTests.cs

@@ -12,11 +12,13 @@ namespace ICSharpCode.NRefactory.TypeSystem
 	[TestFixture]
 	public class ReflectionHelperTests
 	{
+		ITypeResolveContext context = CecilLoaderTests.Mscorlib;
+		
 		void TestGetClass(Type type)
 		{
 			ITypeDefinition t = CecilLoaderTests.Mscorlib.GetClass(type);
 			Assert.NotNull(t, type.FullName);
-			Assert.AreEqual(type.FullName, t.DotNetName);
+			Assert.AreEqual(type.FullName, t.ReflectionName);
 		}
 		
 		[Test]
@@ -53,25 +55,25 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		public void TestToTypeReferenceInnerClass()
 		{
 			Assert.AreEqual("System.Environment+SpecialFolder",
-			                typeof(Environment.SpecialFolder).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(Environment.SpecialFolder).ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		[Test]
 		public void TestToTypeReferenceUnboundGenericClass()
 		{
 			Assert.AreEqual("System.Action`1",
-			                typeof(Action<>).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(Action<>).ToTypeReference().Resolve(context).ReflectionName);
 			Assert.AreEqual("System.Action`2",
-			                typeof(Action<,>).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(Action<,>).ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		[Test]
 		public void TestToTypeReferenceBoundGenericClass()
 		{
 			Assert.AreEqual("System.Action`1[[System.String]]",
-			                typeof(Action<string>).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(Action<string>).ToTypeReference().Resolve(context).ReflectionName);
 			Assert.AreEqual("System.Action`2[[System.Int32],[System.Int16]]",
-			                typeof(Action<int, short>).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(Action<int, short>).ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		
@@ -79,56 +81,56 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		public void TestToTypeReferenceNullableType()
 		{
 			Assert.AreEqual("System.Nullable`1[[System.Int32]]",
-			                typeof(int?).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(int?).ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		[Test]
 		public void TestToTypeReferenceInnerClassInUnboundGenericType()
 		{
 			Assert.AreEqual("System.Collections.Generic.Dictionary`2+ValueCollection[[`0],[`1]]",
-			                typeof(Dictionary<,>.ValueCollection).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(Dictionary<,>.ValueCollection).ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		[Test]
 		public void TestToTypeReferenceInnerClassInBoundGenericType()
 		{
 			Assert.AreEqual("System.Collections.Generic.Dictionary`2+KeyCollection[[System.String],[System.Int32]]",
-			                typeof(Dictionary<string, int>.KeyCollection).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(Dictionary<string, int>.KeyCollection).ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		[Test]
 		public void TestToTypeReferenceArrayType()
 		{
 			Assert.AreEqual(typeof(int[]).FullName,
-			                typeof(int[]).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(int[]).ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		[Test]
 		public void TestToTypeReferenceMultidimensionalArrayType()
 		{
 			Assert.AreEqual(typeof(int[,]).FullName,
-			                typeof(int[,]).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(int[,]).ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		[Test]
 		public void TestToTypeReferenceJaggedMultidimensionalArrayType()
 		{
 			Assert.AreEqual(typeof(int[,][,,]).FullName,
-			                typeof(int[,][,,]).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(int[,][,,]).ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		[Test]
 		public void TestToTypeReferencePointerType()
 		{
 			Assert.AreEqual(typeof(int*).FullName,
-			                typeof(int*).ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(int*).ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		[Test]
 		public void TestToTypeReferenceByReferenceType()
 		{
 			Assert.AreEqual(typeof(int).MakeByRefType().FullName,
-			                typeof(int).MakeByRefType().ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                typeof(int).MakeByRefType().ToTypeReference().Resolve(context).ReflectionName);
 		}
 		
 		[Test]
@@ -138,11 +140,23 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			Type parameterType = convertAllInfo.GetParameters()[0].ParameterType; // Converter[[`0],[``0]]
 			// cannot resolve generic types without knowing the parent entity:
 			Assert.AreEqual("System.Converter`2[[?],[?]]",
-			                parameterType.ToTypeReference().Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                parameterType.ToTypeReference().Resolve(context).ReflectionName);
 			// now try with parent entity:
-			IMethod convertAll = CecilLoaderTests.Mscorlib.GetClass(typeof(List<>)).Methods.Single(m => m.Name == "ConvertAll");
+			IMethod convertAll = context.GetClass(typeof(List<>)).Methods.Single(m => m.Name == "ConvertAll");
 			Assert.AreEqual("System.Converter`2[[`0],[``0]]",
-			                parameterType.ToTypeReference(entity: convertAll).Resolve(CecilLoaderTests.Mscorlib).DotNetName);
+			                parameterType.ToTypeReference(entity: convertAll).Resolve(context).ReflectionName);
+		}
+		
+		[Test]
+		public void ParseReflectionNameSimpleTypes()
+		{
+			Assert.AreEqual("System.Int32", ReflectionHelper.ParseReflectionName("System.Int32").Resolve(context).ReflectionName);
+			Assert.AreEqual("System.Int32&", ReflectionHelper.ParseReflectionName("System.Int32&").Resolve(context).ReflectionName);
+			Assert.AreEqual("System.Int32*&", ReflectionHelper.ParseReflectionName("System.Int32*&").Resolve(context).ReflectionName);
+			Assert.AreEqual("System.Int32", ReflectionHelper.ParseReflectionName(typeof(int).AssemblyQualifiedName).Resolve(context).ReflectionName);
+			Assert.AreEqual("System.Action`1[[System.String]]", ReflectionHelper.ParseReflectionName("System.Action`1[[System.String]]").Resolve(context).ReflectionName);
+			Assert.AreEqual("System.Action`1[[System.String]]", ReflectionHelper.ParseReflectionName("System.Action`1[[System.String, mscorlib]]").Resolve(context).ReflectionName);
+			Assert.AreEqual("System.Int32[,,][,]", ReflectionHelper.ParseReflectionName(typeof(int[,][,,]).AssemblyQualifiedName).Resolve(context).ReflectionName);
 		}
 	}
 }

ICSharpCode.NRefactory.Tests/TypeSystem/TypeSystemTests.cs

@@ -22,7 +22,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		[SetUpAttribute]
 		public void SetUp()
 		{
-			ctx = AggregateTypeResolveContext.Combine(testCasePC, CecilLoaderTests.Mscorlib);
+			ctx = CompositeTypeResolveContext.Combine(testCasePC, CecilLoaderTests.Mscorlib);
 		}
 		
 		ITypeDefinition GetClass(Type type)
@@ -37,7 +37,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			Assert.AreEqual(typeof(SimplePublicClass).Name, c.Name);
 			Assert.AreEqual(typeof(SimplePublicClass).FullName, c.FullName);
 			Assert.AreEqual(typeof(SimplePublicClass).Namespace, c.Namespace);
-			Assert.AreEqual(typeof(SimplePublicClass).FullName, c.DotNetName);
+			Assert.AreEqual(typeof(SimplePublicClass).FullName, c.ReflectionName);
 			
 			Assert.AreEqual(Accessibility.Public, c.Accessibility);
 			Assert.IsFalse(c.IsAbstract);
@@ -77,26 +77,26 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			ITypeDefinition testClass = testCasePC.GetClass(typeof(DynamicTest));
 			
 			IMethod m1 = testClass.Methods.Single(me => me.Name == "DynamicGenerics1");
-			Assert.AreEqual("System.Collections.Generic.List`1[[dynamic]]", m1.ReturnType.Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.Collections.Generic.List`1[[dynamic]]", m1.ReturnType.Resolve(ctx).ReflectionName);
-			Assert.AreEqual("System.Action`3[[System.Object],[dynamic[]],[System.Object]]", m1.Parameters[0].Type.Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.Action`3[[System.Object],[dynamic[]],[System.Object]]", m1.Parameters[0].Type.Resolve(ctx).ReflectionName);
 			
 			IMethod m2 = testClass.Methods.Single(me => me.Name == "DynamicGenerics2");
-			Assert.AreEqual("System.Action`3[[System.Object],[dynamic],[System.Object]]", m2.Parameters[0].Type.Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.Action`3[[System.Object],[dynamic],[System.Object]]", m2.Parameters[0].Type.Resolve(ctx).ReflectionName);
 			
 			IMethod m3 = testClass.Methods.Single(me => me.Name == "DynamicGenerics3");
-			Assert.AreEqual("System.Action`3[[System.Int32],[dynamic],[System.Object]]", m3.Parameters[0].Type.Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.Action`3[[System.Int32],[dynamic],[System.Object]]", m3.Parameters[0].Type.Resolve(ctx).ReflectionName);
 			
 			IMethod m4 = testClass.Methods.Single(me => me.Name == "DynamicGenerics4");
-			Assert.AreEqual("System.Action`3[[System.Int32[]],[dynamic],[System.Object]]", m4.Parameters[0].Type.Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.Action`3[[System.Int32[]],[dynamic],[System.Object]]", m4.Parameters[0].Type.Resolve(ctx).ReflectionName);
 			
 			IMethod m5 = testClass.Methods.Single(me => me.Name == "DynamicGenerics5");
-			Assert.AreEqual("System.Action`3[[System.Int32*[]],[dynamic],[System.Object]]", m5.Parameters[0].Type.Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.Action`3[[System.Int32*[]],[dynamic],[System.Object]]", m5.Parameters[0].Type.Resolve(ctx).ReflectionName);
 			
 			IMethod m6 = testClass.Methods.Single(me => me.Name == "DynamicGenerics6");
-			Assert.AreEqual("System.Action`3[[System.Object],[dynamic],[System.Object]]&", m6.Parameters[0].Type.Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.Action`3[[System.Object],[dynamic],[System.Object]]&", m6.Parameters[0].Type.Resolve(ctx).ReflectionName);
 			
 			IMethod m7 = testClass.Methods.Single(me => me.Name == "DynamicGenerics7");
-			Assert.AreEqual("System.Action`3[[System.Int32[][,]],[dynamic],[System.Object]]", m7.Parameters[0].Type.Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.Action`3[[System.Int32[][,]],[dynamic],[System.Object]]", m7.Parameters[0].Type.Resolve(ctx).ReflectionName);
 		}
 		
 		[Test]
@@ -117,7 +117,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			Assert.AreEqual("System.Collections.Generic.IDictionary", crt.FullName);
 			Assert.AreEqual("System.String", crt.TypeArguments[0].FullName);
 			// ? for NUnit.TestAttribute (because that assembly isn't in ctx)
-			Assert.AreEqual("System.Collections.Generic.IList`1[[?]]", crt.TypeArguments[1].DotNetName);
+			Assert.AreEqual("System.Collections.Generic.IList`1[[?]]", crt.TypeArguments[1].ReflectionName);
 		}
 		
 		[Test]
@@ -140,7 +140,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			Assert.AreSame(m, m.TypeParameters[0].ParentMethod);
 			Assert.AreSame(m, m.TypeParameters[1].ParentMethod);
 			
-			Assert.AreEqual("System.IComparable`1[[``1]]", m.TypeParameters[0].Constraints[0].Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.IComparable`1[[``1]]", m.TypeParameters[0].Constraints[0].Resolve(ctx).ReflectionName);
 			Assert.AreSame(m.TypeParameters[0], m.TypeParameters[1].Constraints[0].Resolve(ctx));
 		}
 		
@@ -202,8 +202,8 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			var e = testCasePC.GetClass(typeof(MyEnum));
 			Assert.AreEqual(ClassType.Enum, e.ClassType);
 			Assert.AreEqual(false, e.IsReferenceType);
-			Assert.AreEqual("System.Int16", e.BaseTypes[0].Resolve(ctx).DotNetName);
+			Assert.AreEqual("System.Int16", e.BaseTypes[0].Resolve(ctx).ReflectionName);
-			Assert.AreEqual(new[] { "System.Enum" }, e.GetBaseTypes(ctx).Select(t => t.DotNetName).ToArray());
+			Assert.AreEqual(new[] { "System.Enum" }, e.GetBaseTypes(ctx).Select(t => t.ReflectionName).ToArray());
 		}
 		
 		[Test]

ICSharpCode.NRefactory/CSharp/Resolver/CSharpResolver.cs

@@ -178,7 +178,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 				get { return string.Empty; }
 			}
 			
-			string INamedElement.DotNetName {
+			string INamedElement.ReflectionName {
 				get { return "operator"; }
 			}
 			

ICSharpCode.NRefactory/CSharp/Resolver/Conversions.cs

@@ -21,7 +21,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			if (context == null)
 				throw new ArgumentNullException("context");
 			this.context = context;
-			this.objectType = context.GetClass(typeof(object)) ?? SharedTypes.UnknownType;
+			this.objectType = TypeCode.Object.ToTypeReference().Resolve(context);
 			this.dynamicErasure = new DynamicErasure(this);
 		}
 		

ICSharpCode.NRefactory/ICSharpCode.NRefactory.csproj

@@ -179,7 +179,7 @@
     <Compile Include="TypeSystem\Implementation\DefaultProperty.cs" />
     <Compile Include="TypeSystem\Implementation\DefaultTypeParameter.cs" />
     <Compile Include="TypeSystem\Implementation\GetClassTypeReference.cs" />
-    <Compile Include="TypeSystem\Implementation\AggregateTypeResolveContext.cs" />
+    <Compile Include="TypeSystem\Implementation\CompositeTypeResolveContext.cs" />
     <Compile Include="TypeSystem\Implementation\NestedTypeReference.cs" />
     <Compile Include="TypeSystem\Implementation\ProxyTypeResolveContext.cs" />
     <Compile Include="TypeSystem\Implementation\DefaultTypeDefinition.cs" />
@@ -206,6 +206,7 @@
     <Compile Include="TypeSystem\ITypeResolveContext.cs" />
     <Compile Include="TypeSystem\NullableType.cs" />
     <Compile Include="TypeSystem\ParameterizedType.cs" />
+    <Compile Include="TypeSystem\ReflectionNameParseException.cs" />
     <Compile Include="TypeSystem\TypeVisitor.cs" />
     <Compile Include="TypeSystem\IVariable.cs" />
     <Compile Include="TypeSystem\PointerType.cs" />

ICSharpCode.NRefactory/TypeSystem/CecilLoader.cs

@@ -48,7 +48,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 				TypeStorage typeStorage = new TypeStorage();
 				CecilProjectContent pc = new CecilProjectContent(typeStorage, assemblyDefinition.Name.FullName, assemblyAttributes.AsReadOnly());
 				
-				this.EarlyBindContext = AggregateTypeResolveContext.Combine(pc, this.EarlyBindContext);
+				this.EarlyBindContext = CompositeTypeResolveContext.Combine(pc, this.EarlyBindContext);
 				List<CecilTypeDefinition> types = new List<CecilTypeDefinition>();
 				foreach (ModuleDefinition module in assemblyDefinition.Modules) {
 					foreach (TypeDefinition td in module.Types) {

ICSharpCode.NRefactory/TypeSystem/INamedElement.cs

@@ -54,7 +54,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		/// "System.Collections.Generic.List`1[[System.String]]" for List<string>
 		/// "System.Environment+SpecialFolder" for Environment.SpecialFolder
 		/// </returns>
-		string DotNetName {
+		string ReflectionName {
 			get;
 		}
 	}
@@ -83,7 +83,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			}
 		}
 		
-		string INamedElement.DotNetName {
+		string INamedElement.ReflectionName {
 			get {
 				Contract.Ensures(!string.IsNullOrEmpty(Contract.Result<string>()));
 				return null;

ICSharpCode.NRefactory/TypeSystem/ISynchronizedTypeResolveContext.cs

@@ -17,6 +17,9 @@ namespace ICSharpCode.NRefactory.TypeSystem
 	/// A simple implementation might enter a ReaderWriterLock when the synchronized context
 	/// is created, and releases the lock when Dispose() is called.
 	/// However, implementations based on immutable data structures are also possible.
+	/// 
+	/// Calling Synchronize() on an already synchronized context is possible, but has no effect.
+	/// Only disposing the outermost ISynchronizedTypeResolveContext releases the lock.
 	/// </remarks>
 	public interface ISynchronizedTypeResolveContext : ITypeResolveContext, IDisposable
 	{

ICSharpCode.NRefactory/TypeSystem/IType.cs

@@ -178,7 +178,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			}
 		}
 		
-		string INamedElement.DotNetName {
+		string INamedElement.ReflectionName {
 			get {
 				Contract.Ensures(Contract.Result<string>() != null);
 				return null;

ICSharpCode.NRefactory/TypeSystem/ITypeResolveContext.cs

@@ -66,6 +66,22 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		/// However, implementations based on immutable data structures are also possible.
 		/// </remarks>
 		ISynchronizedTypeResolveContext Synchronize();
+		
+		/// <summary>
+		/// Returns an object if caching information based on this resolve context is allowed,
+		/// or null if caching is not allowed.
+		/// Whenever the resolve context changes in some way, this property must return a new object.
+		/// </summary>
+		/// <remarks>
+		/// This allows consumers to see whether their cache is still valid by comparing the current
+		/// CacheToken with the one they saw before.
+		/// 
+		/// For ISynchronizedTypeResolveContext, this property could be implemented as <c>return this;</c>.
+		/// However, it is a bad idea to use an object is large or that references a large object graph
+		/// -- consumers may store a reference to the cache token indefinately, possible extending the
+		/// lifetime of the ITypeResolveContext.
+		/// </remarks>
+		object CacheToken { get; }
 	}
 	
 	[ContractClassFor(typeof(ITypeResolveContext))]
@@ -104,5 +120,9 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			Contract.Ensures(Contract.Result<IEnumerable<ITypeDefinition>>() != null);
 			return null;
 		}
+		
+		object ITypeResolveContext.CacheToken {
+			get { return null; }
+		}
 	}
 }

ICSharpCode.NRefactory/TypeSystem/Implementation/AbstractMember.cs

@@ -237,13 +237,13 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 			get { return declaringTypeDefinition.Namespace; }
 		}
 		
-		public virtual string DotNetName {
+		public virtual string ReflectionName {
-			get { return this.DeclaringType.DotNetName + "." + this.Name; }
+			get { return this.DeclaringType.ReflectionName + "." + this.Name; }
 		}
 		
 		public override string ToString()
 		{
-			return "[" + EntityType + " " + DotNetName + ":" + ReturnType + "]";
+			return "[" + EntityType + " " + ReflectionName + ":" + ReturnType + "]";
 		}
 		
 		public virtual void PrepareForInterning(IInterningProvider provider)

ICSharpCode.NRefactory/TypeSystem/Implementation/AbstractType.cs

@@ -32,7 +32,7 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 			get { return string.Empty; }
 		}
 		
-		public virtual string DotNetName {
+		public virtual string ReflectionName {
 			get { return this.FullName; }
 		}
 		
@@ -101,7 +101,7 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		
 		public override string ToString()
 		{
-			return this.DotNetName;
+			return this.ReflectionName;
 		}
 		
 		public virtual IType AcceptVisitor(TypeVisitor visitor)

ICSharpCode.NRefactory/TypeSystem/Implementation/AggregateTypeResolveContext.cs

@@ -1,98 +0,0 @@
-// Copyright (c) 2010 AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
-// This code is distributed under MIT X11 license (for details please see \doc\license.txt)
-
-using System;
-using System.Collections.Generic;
-using System.Linq;
-
-namespace ICSharpCode.NRefactory.TypeSystem.Implementation
-{
-	/// <summary>
-	/// Represents multiple type resolve contexts.
-	/// </summary>
-	public class AggregateTypeResolveContext : ITypeResolveContext
-	{
-		/// <summary>
-		/// Creates a <see cref="MultiTypeResolveContext"/> that combines the given resolve contexts.
-		/// If one of the input parameters is null, the other input parameter is returned directly.
-		/// If both input parameters are null, the function returns null.
-		/// </summary>
-		public static ITypeResolveContext Combine(ITypeResolveContext a, ITypeResolveContext b)
-		{
-			if (a == null)
-				return b;
-			if (b == null)
-				return a;
-			return new AggregateTypeResolveContext(new [] { a, b });
-		}
-		
-		readonly ITypeResolveContext[] contexts;
-		
-		/// <summary>
-		/// Creates a new <see cref="MultiTypeResolveContext"/>
-		/// </summary>
-		public AggregateTypeResolveContext(IEnumerable<ITypeResolveContext> contexts)
-		{
-			if (contexts == null)
-				throw new ArgumentNullException("contexts");
-			this.contexts = contexts.ToArray();
-		}
-		
-		/// <inheritdoc/>
-		public ITypeDefinition GetClass(string fullTypeName, int typeParameterCount, StringComparer nameComparer)
-		{
-			foreach (ITypeResolveContext context in contexts) {
-				ITypeDefinition d = context.GetClass(fullTypeName, typeParameterCount, nameComparer);
-				if (d != null)
-					return d;
-			}
-			return null;
-		}
-		
-		/// <inheritdoc/>
-		public IEnumerable<ITypeDefinition> GetClasses()
-		{
-			return contexts.SelectMany(c => c.GetClasses());
-		}
-		
-		/// <inheritdoc/>
-		public IEnumerable<ITypeDefinition> GetClasses(string nameSpace, StringComparer nameComparer)
-		{
-			return contexts.SelectMany(c => c.GetClasses(nameSpace, nameComparer));
-		}
-		
-		/// <inheritdoc/>
-		public IEnumerable<string> GetNamespaces()
-		{
-			return contexts.SelectMany(c => c.GetNamespaces()).Distinct();
-		}
-		
-		/// <inheritdoc/>
-		public ISynchronizedTypeResolveContext Synchronize()
-		{
-			ISynchronizedTypeResolveContext[] sync = new ISynchronizedTypeResolveContext[contexts.Length];
-			for (int i = 0; i < sync.Length; i++) {
-				sync[i] = contexts[i].Synchronize();
-			}
-			return new AggregateSynchronizedTypeResolveContext(sync);
-		}
-		
-		sealed class AggregateSynchronizedTypeResolveContext : AggregateTypeResolveContext, ISynchronizedTypeResolveContext
-		{
-			readonly ISynchronizedTypeResolveContext[] sync;
-			
-			public AggregateSynchronizedTypeResolveContext(ISynchronizedTypeResolveContext[] sync)
-				: base(sync)
-			{
-				this.sync = sync;
-			}
-			
-			public void Dispose()
-			{
-				foreach (var element in sync) {
-					element.Dispose();
-				}
-			}
-		}
-	}
-}

ICSharpCode.NRefactory/TypeSystem/Implementation/CompositeTypeResolveContext.cs

@@ -0,0 +1,148 @@
+// Copyright (c) 2010 AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under MIT X11 license (for details please see \doc\license.txt)
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+
+namespace ICSharpCode.NRefactory.TypeSystem.Implementation
+{
+	/// <summary>
+	/// Represents multiple type resolve contexts.
+	/// </summary>
+	public class CompositeTypeResolveContext : ITypeResolveContext
+	{
+		/// <summary>
+		/// Creates a <see cref="CompositeTypeResolveContext"/> that combines the given resolve contexts.
+		/// If one of the input parameters is null, the other input parameter is returned directly.
+		/// If both input parameters are null, the function returns null.
+		/// </summary>
+		public static ITypeResolveContext Combine(ITypeResolveContext a, ITypeResolveContext b)
+		{
+			if (a == null)
+				return b;
+			if (b == null)
+				return a;
+			return new CompositeTypeResolveContext(new [] { a, b });
+		}
+		
+		readonly ITypeResolveContext[] children;
+		
+		/// <summary>
+		/// Creates a new <see cref="CompositeTypeResolveContext"/>
+		/// </summary>
+		public CompositeTypeResolveContext(IEnumerable<ITypeResolveContext> children)
+		{
+			if (children == null)
+				throw new ArgumentNullException("children");
+			this.children = children.ToArray();
+			foreach (ITypeResolveContext c in this.children) {
+				if (c == null)
+					throw new ArgumentException("children enumeration contains nulls");
+			}
+		}
+		
+		private CompositeTypeResolveContext(ITypeResolveContext[] children)
+		{
+			Debug.Assert(children != null);
+			this.children = children;
+		}
+		
+		/// <inheritdoc/>
+		public ITypeDefinition GetClass(string fullTypeName, int typeParameterCount, StringComparer nameComparer)
+		{
+			foreach (ITypeResolveContext context in children) {
+				ITypeDefinition d = context.GetClass(fullTypeName, typeParameterCount, nameComparer);
+				if (d != null)
+					return d;
+			}
+			return null;
+		}
+		
+		/// <inheritdoc/>
+		public IEnumerable<ITypeDefinition> GetClasses()
+		{
+			return children.SelectMany(c => c.GetClasses());
+		}
+		
+		/// <inheritdoc/>
+		public IEnumerable<ITypeDefinition> GetClasses(string nameSpace, StringComparer nameComparer)
+		{
+			return children.SelectMany(c => c.GetClasses(nameSpace, nameComparer));
+		}
+		
+		/// <inheritdoc/>
+		public IEnumerable<string> GetNamespaces()
+		{
+			return children.SelectMany(c => c.GetNamespaces()).Distinct();
+		}
+		
+		/// <inheritdoc/>
+		public virtual ISynchronizedTypeResolveContext Synchronize()
+		{
+			return Synchronize(new object());
+		}
+		
+		ISynchronizedTypeResolveContext Synchronize(object cacheToken)
+		{
+			ISynchronizedTypeResolveContext[] sync = new ISynchronizedTypeResolveContext[children.Length];
+			bool success = false;
+			try {
+				for (int i = 0; i < sync.Length; i++) {
+					sync[i] = children[i].Synchronize();
+					if (sync[i] == null)
+						throw new InvalidOperationException(children[i] + ".ToString() returned null");
+				}
+				ISynchronizedTypeResolveContext r = new CompositeSynchronizedTypeResolveContext(sync, cacheToken);
+				success = true;
+				return r;
+			} finally {
+				if (!success) {
+					// something went wrong, so immediately dispose the contexts we acquired
+					for (int i = 0; i < sync.Length; i++) {
+						if (sync[i] != null)
+							sync[i].Dispose();
+					}
+				}
+			}
+		}
+		
+		public virtual object CacheToken {
+			// We don't know if our input contexts are mutable, so, to be on the safe side,
+			// we don't implement caching here.
+			get { return null; }
+		}
+		
+		sealed class CompositeSynchronizedTypeResolveContext : CompositeTypeResolveContext, ISynchronizedTypeResolveContext
+		{
+			readonly object cacheToken;
+			
+			public CompositeSynchronizedTypeResolveContext(ISynchronizedTypeResolveContext[] children, object cacheToken)
+				: base(children)
+			{
+				Debug.Assert(cacheToken != null);
+				this.cacheToken = cacheToken;
+			}
+			
+			public void Dispose()
+			{
+				foreach (ISynchronizedTypeResolveContext element in children) {
+					element.Dispose();
+				}
+			}
+			
+			public override object CacheToken {
+				// I expect CompositeTypeResolveContext to be used for almost all resolver operations,
+				// so this is the only place where implementing cacheToken is really important.
+				get { return cacheToken; }
+			}
+			
+			public override ISynchronizedTypeResolveContext Synchronize()
+			{
+				// re-use the same cache token for nested synchronized contexts
+				return base.Synchronize(cacheToken);
+			}
+		}
+	}
+}

ICSharpCode.NRefactory/TypeSystem/Implementation/DefaultTypeDefinition.cs

@@ -197,15 +197,15 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 			get { return this.ns; }
 		}
 		
-		public string DotNetName {
+		public string ReflectionName {
 			get {
 				if (declaringTypeDefinition != null) {
 					int tpCount = this.TypeParameterCount - declaringTypeDefinition.TypeParameterCount;
 					string combinedName;
 					if (tpCount > 0)
-						combinedName = declaringTypeDefinition.DotNetName + "+" + this.Name + "`" + tpCount.ToString(CultureInfo.InvariantCulture);
+						combinedName = declaringTypeDefinition.ReflectionName + "+" + this.Name + "`" + tpCount.ToString(CultureInfo.InvariantCulture);
 					else
-						combinedName = declaringTypeDefinition.DotNetName + "+" + this.Name;
+						combinedName = declaringTypeDefinition.ReflectionName + "+" + this.Name;
 					return combinedName;
 				} else {
 					int tpCount = this.TypeParameterCount;
@@ -523,7 +523,7 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		
 		public override string ToString()
 		{
-			return DotNetName;
+			return ReflectionName;
 		}
 		
 		/// <summary>

ICSharpCode.NRefactory/TypeSystem/Implementation/DefaultTypeParameter.cs

@@ -71,7 +71,7 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 			get { return string.Empty; }
 		}
 		
-		public string DotNetName {
+		public string ReflectionName {
 			get {
 				if (parent is IMethod)
 					return "``" + index.ToString();

ICSharpCode.NRefactory/TypeSystem/Implementation/GetClassTypeReference.cs

@@ -25,6 +25,18 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		{
 			if (context == null)
 				throw new ArgumentNullException("context");
+			// TODO: caching idea: if these lookups are a performance problem and the same GetClassTypeReference
+			// is asked to resolve lots of times in a row, try the following:
+			// Give ITypeResolveContext a property "object CacheToken { get; }" which is non-null if the
+			// context supports caching, and returns the same object only as long as the context is unchanged.
+			
+			// Then store a thread-local array KeyValuePair<GetClassTypeReference, IType> with the last 5 (?) resolved
+			// types, and a thread-local reference to the cache token. Subsequent calls with the same cache token
+			// do a quick (reference equality) lookup in the array first.
+			// This should be faster than any ServiceContainer-based caches.
+			// It is worth an idea to make CacheToken implement IServiceContainer, so that other (more expensive)
+			// caches can be registered there, but I think it's troublesome as one ITypeResolveContext should be usable
+			// on multiple threads.
 			return context.GetClass(fullTypeName, typeParameterCount, StringComparer.Ordinal) ?? SharedTypes.UnknownType;
 		}
 		

ICSharpCode.NRefactory/TypeSystem/Implementation/ProxyTypeResolveContext.cs

@@ -53,5 +53,12 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		{
 			return target.Synchronize();
 		}
+		
+		/// <inheritdoc/>
+		public virtual object CacheToken {
+			// Don't forward this by default; we don't know what derived classes are doing;
+			// it might not be cache-safe.
+			get { return null; }
+		}
 	}
 }

ICSharpCode.NRefactory/TypeSystem/Implementation/SimpleProjectContent.cs

@@ -5,60 +5,53 @@ using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
+using System.Threading;
 
 namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 {
 	/// <summary>
 	/// Simple <see cref="IProjectContent"/> implementation that stores the list of classes/namespaces.
+	/// Synchronization is implemented using a <see cref="ReaderWriterLockSlim"/>.
 	/// </summary>
 	/// <remarks>
-	/// This is a decorator around <see cref="TypeStorage"/> that adds support for the IProjectContent interface
+	/// Compared with <see cref="TypeStorage"/>, this class adds support for the IProjectContent interface,
-	/// and for partial classes.
+	/// for partial classes, and for multi-threading.
 	/// </remarks>
-	public class SimpleProjectContent : ProxyTypeResolveContext, IProjectContent
+	public sealed class SimpleProjectContent : IProjectContent
 	{
-		readonly TypeStorage types;
+		// This class is sealed by design:
+		// the synchronization story doesn't mix well with someone trying to extend this class.
+		// If you wanted to derive from this: use delegation, not inheritance.
 		
-		#region Constructors
+		readonly TypeStorage types = new TypeStorage();
-		/// <summary>
+		readonly ReaderWriterLockSlim readerWriterLock = new ReaderWriterLockSlim();
-		/// Creates a new SimpleProjectContent.
-		/// </summary>
-		public SimpleProjectContent()
-			: this(new TypeStorage())
-		{
-		}
-		
-		/// <summary>
-		/// Creates a new SimpleProjectContent that reuses the specified type storage.
-		/// </summary>
-		protected SimpleProjectContent(TypeStorage types)
-			: base(types)
-		{
-			this.types = types;
-			this.assemblyAttributes = new List<IAttribute>();
-			this.readOnlyAssemblyAttributes = assemblyAttributes.AsReadOnly();
-		}
-		#endregion
 		
 		#region AssemblyAttributes
-		readonly List<IAttribute> assemblyAttributes;
+		readonly List<IAttribute> assemblyAttributes = new List<IAttribute>(); // mutable assembly attribute storage
-		readonly ReadOnlyCollection<IAttribute> readOnlyAssemblyAttributes;
+		
+		volatile IAttribute[] readOnlyAssemblyAttributes = {}; // volatile field with copy for reading threads
 		
 		/// <inheritdoc/>
-		public virtual IList<IAttribute> AssemblyAttributes {
+		public IList<IAttribute> AssemblyAttributes {
 			get { return readOnlyAssemblyAttributes; }
 		}
 		
-		void AddAssemblyAttributes(ICollection<IAttribute> attributes)
+		void AddRemoveAssemblyAttributes(ICollection<IAttribute> addedAttributes, ICollection<IAttribute> removedAttributes)
 		{
 			// API uses ICollection instead of IEnumerable to discourage users from evaluating
-			// the list inside the lock (this method is called inside the ReaderWriterLock)
+			// the list inside the lock (this method is called inside the write lock)
-			assemblyAttributes.AddRange(attributes);
+			bool hasChanges = false;
-		}
+			if (removedAttributes != null && removedAttributes.Count > 0) {
-		
+				if (assemblyAttributes.RemoveAll(removedAttributes.Contains) > 0)
-		void RemoveAssemblyAttributes(ICollection<IAttribute> attributes)
+					hasChanges = true;
-		{
+			}
-			assemblyAttributes.RemoveAll(attributes.Contains);
+			if (addedAttributes != null) {
+				assemblyAttributes.AddRange(addedAttributes);
+				hasChanges = true;
+			}
+			
+			if (hasChanges)
+				readOnlyAssemblyAttributes = assemblyAttributes.ToArray();
 		}
 		#endregion
 		
@@ -96,8 +89,8 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		                                 ICollection<IAttribute> oldAssemblyAttributes = null,
 		                                 ICollection<IAttribute> newAssemblyAttributes = null)
 		{
+			readerWriterLock.EnterWriteLock();
 			try {
-				types.ReadWriteLock.EnterWriteLock();
 				if (oldTypes != null) {
 					foreach (var element in oldTypes) {
 						RemoveType(element);
@@ -108,12 +101,93 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 						AddType(element);
 					}
 				}
-				if (oldAssemblyAttributes != null)
+				AddRemoveAssemblyAttributes(oldAssemblyAttributes, newAssemblyAttributes);
-					RemoveAssemblyAttributes(oldAssemblyAttributes);
+			} finally {
-				if (newAssemblyAttributes != null)
+				readerWriterLock.ExitWriteLock();
-					AddAssemblyAttributes(newAssemblyAttributes);
+			}
+		}
+		#endregion
+		
+		#region IProjectContent implementation
+		public ITypeDefinition GetClass(string fullTypeName, int typeParameterCount, StringComparer nameComparer)
+		{
+			readerWriterLock.EnterReadLock();
+			try {
+				return types.GetClass(fullTypeName, typeParameterCount, nameComparer);
+			} finally {
+				readerWriterLock.ExitReadLock();
+			}
+		}
+		
+		public IEnumerable<ITypeDefinition> GetClasses()
+		{
+			readerWriterLock.EnterReadLock();
+			try {
+				// make a copy with ToArray() for thread-safe access
+				return types.GetClasses().ToArray();
+			} finally {
+				readerWriterLock.ExitReadLock();
+			}
+		}
+		
+		public IEnumerable<ITypeDefinition> GetClasses(string nameSpace, StringComparer nameComparer)
+		{
+			readerWriterLock.EnterReadLock();
+			try {
+				// make a copy with ToArray() for thread-safe access
+				return types.GetClasses(nameSpace, nameComparer).ToArray();
+			} finally {
+				readerWriterLock.ExitReadLock();
+			}
+		}
+		
+		public IEnumerable<string> GetNamespaces()
+		{
+			readerWriterLock.EnterReadLock();
+			try {
+				// make a copy with ToArray() for thread-safe access
+				return types.GetNamespaces().ToArray();
 			} finally {
-				types.ReadWriteLock.ExitWriteLock();
+				readerWriterLock.ExitReadLock();
+			}
+		}
+		#endregion
+		
+		#region Synchronization
+		public object CacheToken {
+			get { return null; }
+		}
+		
+		public ISynchronizedTypeResolveContext Synchronize()
+		{
+			// don't acquire the lock on OutOfMemoryException etc.
+			ISynchronizedTypeResolveContext sync = new ReadWriteSynchronizedTypeResolveContext(types, readerWriterLock);
+			readerWriterLock.EnterReadLock();
+			return sync;
+		}
+		
+		sealed class ReadWriteSynchronizedTypeResolveContext : ProxyTypeResolveContext, ISynchronizedTypeResolveContext
+		{
+			ReaderWriterLockSlim readerWriterLock;
+			
+			public ReadWriteSynchronizedTypeResolveContext(ITypeResolveContext target, ReaderWriterLockSlim readerWriterLock)
+				: base(target)
+			{
+				this.readerWriterLock = readerWriterLock;
+			}
+			
+			public void Dispose()
+			{
+				if (readerWriterLock != null) {
+					readerWriterLock.ExitReadLock();
+					readerWriterLock = null;
+				}
+			}
+			
+			public override ISynchronizedTypeResolveContext Synchronize()
+			{
+				// nested Synchronize() calls don't need any locking
+				return new ReadWriteSynchronizedTypeResolveContext(target, null);
 			}
 		}
 		#endregion

ICSharpCode.NRefactory/TypeSystem/Implementation/TypeStorage.cs

@@ -10,16 +10,12 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 {
 	/// <summary>
 	/// Stores a set of types and allows resolving them.
-	/// Synchronization is implemented using a <see cref="ReaderWriterLockSlim"/>.
 	/// </summary>
+	/// <remarks>
+	/// Concurrent read accesses are thread-safe, but a write access concurrent to any other access is not safe.
+	/// </remarks>
 	public sealed class TypeStorage : ITypeResolveContext
 	{
-		ReaderWriterLockSlim readWriteLock = new ReaderWriterLockSlim(LockRecursionPolicy.SupportsRecursion);
-		
-		public ReaderWriterLockSlim ReadWriteLock {
-			get { return readWriteLock; }
-		}
-		
 		#region FullNameAndTypeParameterCount
 		struct FullNameAndTypeParameterCount
 		{
@@ -57,7 +53,7 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		#endregion
 		
 		#region Type Dictionary Storage
-		Dictionary<FullNameAndTypeParameterCount, ITypeDefinition>[] _typeDicts = {
+		volatile Dictionary<FullNameAndTypeParameterCount, ITypeDefinition>[] _typeDicts = {
 			new Dictionary<FullNameAndTypeParameterCount, ITypeDefinition>(FullNameAndTypeParameterCountComparer.Ordinal)
 		};
 		readonly object typeDictsLock = new object();
@@ -66,7 +62,7 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		{
 			// Gets the dictionary for the specified comparer, creating it if necessary.
 			// New dictionaries might be added during read accesses, so this method needs to be thread-safe,
-			// as we allow concurrent read-accesses without locking.
+			// as we allow concurrent read-accesses.
 			var typeDicts = this._typeDicts;
 			foreach (var dict in typeDicts) {
 				FullNameAndTypeParameterCountComparer comparer = (FullNameAndTypeParameterCountComparer)dict.Comparer;
@@ -74,38 +70,33 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 					return dict;
 			}
 			
-			try {
+			// ensure that no other thread can try to lazy-create this (or another) dict
-				// ensure we have a read-lock on the PC so that no concurrent modifications are attempted
+			lock (typeDictsLock) {
-				readWriteLock.EnterReadLock();
+				typeDicts = this._typeDicts; // fetch fresh value after locking
-				// ensure that no other thread can try to lazy-create this (or another) dict
+				// try looking for it again, maybe it was added while we were waiting for a lock
-				lock (typeDictsLock) {
+				// (double-checked locking pattern)
-					typeDicts = this._typeDicts; // fetch fresh value after locking
+				foreach (var dict in typeDicts) {
-					// try looking for it again, maybe it was added while we were waiting for a lock
+					FullNameAndTypeParameterCountComparer comparer = (FullNameAndTypeParameterCountComparer)dict.Comparer;
-					foreach (var dict in typeDicts) {
+					if (comparer.NameComparer == nameComparer)
-						FullNameAndTypeParameterCountComparer comparer = (FullNameAndTypeParameterCountComparer)dict.Comparer;
+						return dict;
-						if (comparer.NameComparer == nameComparer)
-							return dict;
-					}
-					
-					// now create new dict
-					var oldDict = typeDicts[0]; // Ordinal dict
-					var newDict = new Dictionary<FullNameAndTypeParameterCount, ITypeDefinition>(
-						oldDict.Count,
-						new FullNameAndTypeParameterCountComparer(nameComparer));
-					foreach (var pair in oldDict) {
-						// don't use Add() as there might be conflicts in the target language
-						newDict[pair.Key] = pair.Value;
-					}
-					
-					// add the new dict to the array of dicts
-					var newTypeDicts = new Dictionary<FullNameAndTypeParameterCount, ITypeDefinition>[typeDicts.Length + 1];
-					Array.Copy(typeDicts, 0, newTypeDicts, 0, typeDicts.Length);
-					newTypeDicts[typeDicts.Length] = newDict;
-					this._typeDicts = newTypeDicts;
-					return newDict;
 				}
-			} finally {
+				
-				readWriteLock.ExitReadLock();
+				// now create new dict
+				var oldDict = typeDicts[0]; // Ordinal dict
+				var newDict = new Dictionary<FullNameAndTypeParameterCount, ITypeDefinition>(
+					oldDict.Count,
+					new FullNameAndTypeParameterCountComparer(nameComparer));
+				foreach (var pair in oldDict) {
+					// don't use Add() as there might be conflicts in the target language
+					newDict[pair.Key] = pair.Value;
+				}
+				
+				// add the new dict to the array of dicts
+				var newTypeDicts = new Dictionary<FullNameAndTypeParameterCount, ITypeDefinition>[typeDicts.Length + 1];
+				Array.Copy(typeDicts, 0, newTypeDicts, 0, typeDicts.Length);
+				newTypeDicts[typeDicts.Length] = newDict;
+				this._typeDicts = newTypeDicts;
+				return newDict;
 			}
 		}
 		#endregion
@@ -146,31 +137,21 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		#endregion
 		
 		#region Synchronize
-		/// <inheritdoc/>
+		/// <summary>
+		/// TypeStorage is mutable and does not provide any means for synchronization, so this method
+		/// always throws a <see cref="NotSupportedException"/>.
+		/// </summary>
 		public ISynchronizedTypeResolveContext Synchronize()
 		{
-			readWriteLock.EnterReadLock();
+			throw new NotSupportedException();
-			return new ReadWriteSynchronizedTypeResolveContext(this, readWriteLock);
 		}
 		
-		sealed class ReadWriteSynchronizedTypeResolveContext : ProxyTypeResolveContext, ISynchronizedTypeResolveContext
+		/// <inheritdoc/>
-		{
+		public object CacheToken {
-			readonly ReaderWriterLockSlim readWriteLock;
+			// TypeStorage is mutable, so caching is a bad idea.
-			bool disposed;
+			// We could provide a CacheToken if we update it on every modication, but
-			
+			// that's not worth the effort as TypeStorage is rarely directly used in resolve operations.
-			public ReadWriteSynchronizedTypeResolveContext(ITypeResolveContext context, ReaderWriterLockSlim readWriteLock)
+			get { return null; }
-				: base(context)
-			{
-				this.readWriteLock = readWriteLock;
-			}
-			
-			public void Dispose()
-			{
-				if (!disposed) {
-					disposed = true;
-					readWriteLock.ExitReadLock();
-				}
-			}
 		}
 		#endregion
 		
@@ -182,14 +163,9 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		{
 			if (fullName == null)
 				throw new ArgumentNullException("fullName");
-			try {
+			var key = new FullNameAndTypeParameterCount(fullName, typeParameterCount);
-				readWriteLock.EnterWriteLock();
+			foreach (var dict in _typeDicts) {
-				var key = new FullNameAndTypeParameterCount(fullName, typeParameterCount);
+				dict.Remove(key);
-				foreach (var dict in _typeDicts) {
-					dict.Remove(key);
-				}
-			} finally {
-				readWriteLock.ExitWriteLock();
 			}
 		}
 		#endregion
@@ -203,14 +179,9 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		{
 			if (typeDefinition == null)
 				throw new ArgumentNullException("typeDefinition");
-			try {
+			var key = new FullNameAndTypeParameterCount(typeDefinition.FullName, typeDefinition.TypeParameterCount);
-				readWriteLock.EnterWriteLock();
+			foreach (var dict in _typeDicts) {
-				var key = new FullNameAndTypeParameterCount(typeDefinition.FullName, typeDefinition.TypeParameterCount);
+				dict[key] = typeDefinition;
-				foreach (var dict in _typeDicts) {
-					dict[key] = typeDefinition;
-				}
-			} finally {
-				readWriteLock.ExitWriteLock();
 			}
 		}
 		#endregion

ICSharpCode.NRefactory/TypeSystem/Implementation/TypeWithElementType.cs

@@ -28,8 +28,8 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 			get { return elementType.FullName + NameSuffix; }
 		}
 		
-		public override string DotNetName {
+		public override string ReflectionName {
-			get { return elementType.DotNetName + NameSuffix; }
+			get { return elementType.ReflectionName + NameSuffix; }
 		}
 		
 		public abstract string NameSuffix { get; }

ICSharpCode.NRefactory/TypeSystem/ParameterizedType.cs

@@ -115,15 +115,15 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			get { return genericType.Namespace;}
 		}
 		
-		public string DotNetName {
+		public string ReflectionName {
 			get {
-				StringBuilder b = new StringBuilder(genericType.DotNetName);
+				StringBuilder b = new StringBuilder(genericType.ReflectionName);
 				b.Append('[');
 				for (int i = 0; i < typeArguments.Length; i++) {
 					if (i > 0)
 						b.Append(',');
 					b.Append('[');
-					b.Append(typeArguments[i].DotNetName);
+					b.Append(typeArguments[i].ReflectionName);
 					b.Append(']');
 				}
 				b.Append(']');
@@ -133,7 +133,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		
 		public override string ToString()
 		{
-			return DotNetName;
+			return ReflectionName;
 		}
 		
 		public ReadOnlyCollection<IType> TypeArguments {

ICSharpCode.NRefactory/TypeSystem/ReflectionHelper.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Text;
 using ICSharpCode.NRefactory.TypeSystem.Implementation;
 
 namespace ICSharpCode.NRefactory.TypeSystem
@@ -22,6 +23,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		/// </summary>
 		public sealed class Dynamic {}
 		
+		#region ITypeResolveContext.GetClass(Type)
 		/// <summary>
 		/// Retrieves a class.
 		/// </summary>
@@ -55,7 +57,9 @@ namespace ICSharpCode.NRefactory.TypeSystem
 				return context.GetClass(name, typeParameterCount, StringComparer.Ordinal);
 			}
 		}
+		#endregion
 		
+		#region Type.ToTypeReference()
 		/// <summary>
 		/// Creates a reference to the specified type.
 		/// </summary>
@@ -90,7 +94,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 					}
 					return SharedTypes.UnknownType;
 				} else {
-					ITypeDefinition c = (entity as ITypeDefinition) ?? (entity is IMember ? ((IMember)entity).DeclaringTypeDefinition : null);
+					ITypeDefinition c = (entity as ITypeDefinition) ?? (entity != null ? entity.DeclaringTypeDefinition : null);
 					if (c != null && type.GenericParameterPosition < c.TypeParameters.Count) {
 						if (c.TypeParameters[type.GenericParameterPosition].Name == type.Name) {
 							return c.TypeParameters[type.GenericParameterPosition];
@@ -113,7 +117,9 @@ namespace ICSharpCode.NRefactory.TypeSystem
 				return new GetClassTypeReference(name, typeParameterCount);
 			}
 		}
+		#endregion
 		
+		#region SplitTypeParameterCountFromReflectionName
 		/// <summary>
 		/// Removes the ` with type parameter count from the reflection name.
 		/// </summary>
@@ -146,7 +152,9 @@ namespace ICSharpCode.NRefactory.TypeSystem
 					return reflectionName;
 			}
 		}
+		#endregion
 		
+		#region TypeCode.ToTypeReference()
 		static readonly ITypeReference[] primitiveTypeReferences = {
 			SharedTypes.UnknownType, // TypeCode.Empty
 			new GetClassTypeReference("System.Object", 0),
@@ -178,7 +186,9 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		{
 			return primitiveTypeReferences[(int)typeCode];
 		}
+		#endregion
 		
+		#region GetTypeCode
 		static readonly Dictionary<string, TypeCode> typeNameToCodeDict = new Dictionary<string, TypeCode> {
 			{ "System.Object",   TypeCode.Object },
 			{ "System.DBNull",   TypeCode.DBNull },
@@ -211,5 +221,180 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			else
 				return TypeCode.Empty;
 		}
+		#endregion
+		
+		#region ParseReflectionName
+		/// <summary>
+		/// Parses a reflection name into a type reference.
+		/// </summary>
+		public static ITypeReference ParseReflectionName(string reflectionTypeName, IEntity parentEntity = null)
+		{
+			int pos = 0;
+			ITypeReference r = ParseReflectionName(reflectionTypeName, ref pos, parentEntity);
+			if (pos < reflectionTypeName.Length)
+				throw new ReflectionNameParseException(pos, "Expected end of type name");
+			return r;
+		}
+		
+		static bool IsReflectionNameSpecialCharacter(char c)
+		{
+			switch (c) {
+				case '+':
+				case '`':
+				case '[':
+				case ']':
+				case ',':
+				case '*':
+				case '&':
+					return true;
+				default:
+					return false;
+			}
+		}
+		
+		static ITypeReference ParseReflectionName(string reflectionTypeName, ref int pos, IEntity entity)
+		{
+			if (pos == reflectionTypeName.Length)
+				throw new ReflectionNameParseException(pos, "Unexpected end");
+			if (reflectionTypeName[pos] == '`') {
+				// type parameter reference
+				pos++;
+				if (pos == reflectionTypeName.Length)
+					throw new ReflectionNameParseException(pos, "Unexpected end");
+				if (reflectionTypeName[pos] == '`') {
+					// method type parameter reference
+					pos++;
+					int index = ReadTypeParameterCount(reflectionTypeName, ref pos);
+					IMethod method = entity as IMethod;
+					if (method != null && index >= 0 && index < method.TypeParameters.Count)
+						return method.TypeParameters[index];
+					else
+						return SharedTypes.UnknownType;
+				} else {
+					// class type parameter reference
+					int index = ReadTypeParameterCount(reflectionTypeName, ref pos);
+					ITypeDefinition c = (entity as ITypeDefinition) ?? (entity != null ? entity.DeclaringTypeDefinition : null);
+					if (c != null && index >= 0 && index < c.TypeParameters.Count)
+						return c.TypeParameters[index];
+					else
+						return SharedTypes.UnknownType;
+				}
+			}
+			// not a type parameter reference: read the actual type name
+			int tpc;
+			string typeName = ReadTypeName(reflectionTypeName, ref pos, out tpc);
+			ITypeReference reference = new GetClassTypeReference(typeName, tpc);
+			// read type suffixes
+			while (pos < reflectionTypeName.Length) {
+				switch (reflectionTypeName[pos++]) {
+					case '+':
+						typeName = ReadTypeName(reflectionTypeName, ref pos, out tpc);
+						reference = new NestedTypeReference(reference, typeName, tpc);
+						break;
+					case '*':
+						reference = new PointerTypeReference(reference);
+						break;
+					case '&':
+						reference = new ByReferenceTypeReference(reference);
+						break;
+					case '[':
+						// this might be an array or a generic type
+						if (pos == reflectionTypeName.Length)
+							throw new ReflectionNameParseException(pos, "Unexpected end");
+						if (reflectionTypeName[pos] == '[') {
+							// it's a generic type
+							List<ITypeReference> typeArguments = new List<ITypeReference>(tpc);
+							pos++;
+							typeArguments.Add(ParseReflectionName(reflectionTypeName, ref pos, entity));
+							if (pos < reflectionTypeName.Length && reflectionTypeName[pos] == ']')
+								pos++;
+							else
+								throw new ReflectionNameParseException(pos, "Expected end of type argument");
+							
+							while (pos < reflectionTypeName.Length && reflectionTypeName[pos] == ',') {
+								pos++;
+								if (pos < reflectionTypeName.Length && reflectionTypeName[pos] == '[')
+									pos++;
+								else
+									throw new ReflectionNameParseException(pos, "Expected another type argument");
+								
+								typeArguments.Add(ParseReflectionName(reflectionTypeName, ref pos, entity));
+								
+								if (pos < reflectionTypeName.Length && reflectionTypeName[pos] == ']')
+									pos++;
+								else
+									throw new ReflectionNameParseException(pos, "Expected end of type argument");
+							}
+							
+							if (pos < reflectionTypeName.Length && reflectionTypeName[pos] == ']') {
+								pos++;
+								reference = new ParameterizedTypeReference(reference, typeArguments);
+							} else {
+								throw new ReflectionNameParseException(pos, "Expected end of generic type");
+							}
+						} else {
+							// it's an array
+							int dimensions = 1;
+							while (pos < reflectionTypeName.Length && reflectionTypeName[pos] == ',') {
+								dimensions++;
+								pos++;
+							}
+							if (pos < reflectionTypeName.Length && reflectionTypeName[pos] == ']') {
+								pos++; // end of array
+								reference = new ArrayTypeReference(reference, dimensions);
+							} else {
+								throw new ReflectionNameParseException(pos, "Expected array modifier");
+							}
+						}
+						break;
+					case ',':
+						// assembly qualified name, ignore everything up to the end/next ']'
+						while (pos < reflectionTypeName.Length && reflectionTypeName[pos] != ']')
+							pos++;
+						break;
+					default:
+						pos--; // reset pos to the character we couldn't read
+						if (reflectionTypeName[pos] == ']')
+							return reference; // return from a nested generic
+						else
+							throw new ReflectionNameParseException(pos, "Unexpected character: '" + reflectionTypeName[pos] + "'");
+				}
+			}
+			return reference;
+		}
+		
+		static string ReadTypeName(string reflectionTypeName, ref int pos, out int tpc)
+		{
+			int startPos = pos;
+			// skip the simple name portion:
+			while (pos < reflectionTypeName.Length && !IsReflectionNameSpecialCharacter(reflectionTypeName[pos]))
+				pos++;
+			if (pos == startPos)
+				throw new ReflectionNameParseException(pos, "Expected type name");
+			string typeName = reflectionTypeName.Substring(startPos, pos - startPos);
+			if (pos < reflectionTypeName.Length && reflectionTypeName[pos] == '`') {
+				pos++;
+				tpc = ReadTypeParameterCount(reflectionTypeName, ref pos);
+			} else {
+				tpc = 0;
+			}
+			return typeName;
+		}
+		
+		static int ReadTypeParameterCount(string reflectionTypeName, ref int pos)
+		{
+			int startPos = pos;
+			while (pos < reflectionTypeName.Length) {
+				char c = reflectionTypeName[pos];
+				if (c < '0' || c > '9')
+					break;
+				pos++;
+			}
+			int tpc;
+			if (!int.TryParse(reflectionTypeName.Substring(startPos, pos - startPos), out tpc))
+				throw new ReflectionNameParseException(pos, "Expected type parameter count");
+			return tpc;
+		}
+		#endregion
 	}
 }

ICSharpCode.NRefactory/TypeSystem/ReflectionNameParseException.cs

@@ -0,0 +1,45 @@
+
+using System;
+using System.Runtime.Serialization;
+
+namespace ICSharpCode.NRefactory.TypeSystem
+{
+	/// <summary>
+	/// Represents an error while parsing a reflection name.
+	/// </summary>
+	public class ReflectionNameParseException : Exception
+	{
+		int position;
+		
+		public int Position {
+			get { return position; }
+		}
+		
+		public ReflectionNameParseException(int position)
+		{
+			this.position = position;
+		}
+		
+		public ReflectionNameParseException(int position, string message) : base(message)
+		{
+			this.position = position;
+		}
+		
+		public ReflectionNameParseException(int position, string message, Exception innerException) : base(message, innerException)
+		{
+			this.position = position;
+		}
+		
+		// This constructor is needed for serialization.
+		protected ReflectionNameParseException(SerializationInfo info, StreamingContext context) : base(info, context)
+		{
+			position = info.GetInt32("position");
+		}
+		
+		public override void GetObjectData(SerializationInfo info, StreamingContext context)
+		{
+			base.GetObjectData(info, context);
+			info.AddValue("position", position);
+		}
+	}
+}

README

@@ -26,3 +26,101 @@ Null-Object pattern:
 	The pattern also extends to the C# resolver, which always produces a ResolveResult, even in error cases.
 	Use ResolveResult.IsError to detect resolver errors. Also note that many resolver errors still have a meaningful type attached,
 	this allows code completion to work in the presence of minor semantic errors.
+
+FAQ:
+Q:	What is the difference between a type and a type definition?
+
+A:	Basically, a type (IType) is any type in the .NET type system:
+		- an array (ArrayType)
+		- a pointer (PointerType)
+		- a managed reference (ByReferenceType)
+		- a parameterized type (ParameterizedType, e.g. List<int>)
+		- a type parameter (ITypeParameter, e.g. T)
+		- or a type definition (ITypeDefiniton)
+	
+	Type definitions are only classes, structs, enums and delegates.
+	Every type definition is a type, but not every type is a type definition.
+	NRefactory's ITypeDefinition derives from IType, so you can directly use any type definition as a type.
+	In the other direction, you could try to cast a type to ITypeDefinition, or you can call the GetDefinition()
+	method. The GetDefinition() method will also return the underlying ITypeDefinition if given a parameterized type,
+	so "List<int>".GetDefinition() is "List<T>".
+
+Q:	What is the difference betweent type references and types?
+	I've seen lots of duplicated classes (ArrayType vs. ArrayTypeReference, etc.)
+	
+	NRefactory has the concept of the "project content": every assembly/project is stored independently from other assemblies/projects.
+	It is possible to load some source code into a project which contains the type reference "int[]" without having to load
+	mscorlib into NRefactory.
+	So inside the entities stored for the project, the array type is only referenced using an ITypeReference.
+	This interface has a single method:
+	    interface ITypeReference {
+	       IType Resolve(ITypeResolutionContext context);
+	    }
+	By calling the Resolve()-method, you will get back the actual ArrayType.
+	At this point, you have to provide the type resolution context:
+	
+	Note that every type can also be used as type reference - the IType interface derives from ITypeReference.
+	Every IType simply returns itself when the Resolve()-method is called.
+	Types are often directly used as references when source and target of the reference are within the same assembly.
+
+A:	If you've previously used the .NET Reflection API, the concept of type references is new to you.
+
+
+Q:	How do I get the IType or ITypeReference for a primitive type such as string or int?
+	
+A:	Please use:
+		TypeCode.Int32.ToTypeReference().Resolve(context)
+	Skip the Resolve() call if you only need the type reference.
+	
+	ReflectionHelper.ToTypeReference is very fast if given a TypeCode (it simply looks up an existing type reference in an array),
+	and your code will benefit from caching of the resolve result (once that gets implemented for these primitive type references).
+	
+	Avoid using "context.GetClass(typeof(int))" - this call involves Reflection on the System.Type being passed,
+	cannot benefit from any caching implemented in the future, and most importantly: it may return null.
+	And do you always test your code in a scenario where mscorlib isn't contained in the resolve context?
+	The approach suggested above will return SharedTypes.UnknownType when the type cannot be resolved, so you
+	don't run into the risk of getting NullReferenceExceptions.
+
+Q:	Is it thread-safe?
+
+A:	This question is a bit difficult to answer.
+	NRefactory was designed to be usable in a multi-threaded IDE.
+	But of course, this does not mean that everything is thread-safe.
+	
+	First off, there's no hidden static state, so any two operations working on independent data can be executed concurrently.
+	TODO: what about the C# parser? gmcs is full of static state...
+	
+	Some instance methods may use hidden instance state, so it is not safe to e.g use an instance of the CSharp.Resolver.Conversions class
+	concurrently. Instead, you need to create an instance on every thread.
+	
+	In the case of project contents, it is desirable to be able to use them, and all the classes in that project content,
+	on multiple threads - for example to provide code completion in an IDE while a background thread parses more files and adds
+	them to the project content.
+	
+	For this reason, the entity interfaces (ITypeDefinition, IMember, etc.) are designed to be freezable. Once the Freeze() method is
+	called, an entity instance becomes immutable and thread-safe.
+	
+	Whether an ITypeResolveContext is thread-safe depends on the implementation:
+		TypeStorage: thread-safe for concurrent reads, but only if it's not written to (see XML documentation on TypeStorage)
+		CecilProjectContent: immutable and thread-safe
+		SimpleProjectContent: fully thread-safe
+		CompositeTypeResolveContext: depends on the child contexts
+	
+	Usually, you'll work with a set of loaded projects (SimpleProjectContents)
+	and loaded external assemblies (CecilProjectContent).
+	A CompositeTypeResolveContext representing such a set is thread-safe.
+	
+	Hoever, some algorithms can become confused if two GetClass() calls with same arguments produce different
+	results (e.g. because another thread updated a class definition).
+	Also, there's a performance problem: if you have a composite of 15 SimpleProjectContents and the resolve algorithm
+	requests 100 types, that's 1500 times entering and leaving the read-lock.
+	Moreoever, the ITypeResolveContext methods that return collections need to create a copy of the collection.
+	
+	The solution is to make the read lock more coarse-grained:
+		using (var syncContext = compositeTypeResolveContext.Synchronize()) {
+			resolver.ResolveStuff(syncContext);
+		}
+	On the call to Synchronize(), all 15 SimpleProjectContents are locked for reading.
+	The return value "syncContext" can then be used to access the type resolve context without further synchronization overhead.
+	Once the return value is disposed, the read-locks are released.
+