Make DefaultTypeDefinition.FullName cache thread-safe.

ICSharpCode.NRefactory.CSharp/Ast/CSharpModifierToken.cs

@@ -57,8 +57,8 @@ namespace ICSharpCode.NRefactory.CSharp
 			Modifiers.Abstract, Modifiers.Virtual, Modifiers.Sealed, Modifiers.Static, Modifiers.Override,
 			Modifiers.Readonly, Modifiers.Volatile,
 			Modifiers.Extern, Modifiers.Partial, Modifiers.Const,
-			Modifiers.Any,
-			Modifiers.Async
+			Modifiers.Async,
+			Modifiers.Any
 		};
 		
 		public static IEnumerable<Modifiers> AllModifiers {
@@ -105,12 +105,11 @@ namespace ICSharpCode.NRefactory.CSharp
 					return "volatile";
 				case Modifiers.Unsafe:
 					return "unsafe";
-				case Modifiers.Any:
-					// even though it's used for patterns only, it needs to be in this list to be usable in the AST
-					return "any";
 				case Modifiers.Async:
-					// even though it's used for patterns only, it needs to be in this list to be usable in the AST
 					return "async";
+				case Modifiers.Any:
+					// even though it's used for pattern matching only, 'any' needs to be in this list to be usable in the AST
+					return "any";
 				default:
 					throw new NotSupportedException("Invalid value for Modifiers");
 			}

ICSharpCode.NRefactory/TypeSystem/Implementation/DefaultTypeDefinition.cs

@@ -216,16 +216,25 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 			}
 		}
 		
-		string cachedFullName = null;
+		[NonSerialized]
+		volatile string cachedFullName;
+		
 		public string FullName {
 			get {
-				if (cachedFullName != null)
-					return cachedFullName;
-				if (declaringTypeDefinition != null) 
-					return cachedFullName = declaringTypeDefinition.FullName + "." + this.name;
-				if (string.IsNullOrEmpty(ns))
-					return cachedFullName = this.name;
-				return cachedFullName = this.ns + "." + this.name;
+				string fullName = this.cachedFullName;
+				if (fullName == null) {
+					// Initialize the cache on demand. Because this might happen after the type definition gets frozen,
+					// the initialization must be thread-safe.
+					if (declaringTypeDefinition != null) {
+						fullName = declaringTypeDefinition.FullName + "." + this.name;
+					} else if (string.IsNullOrEmpty(ns)) {
+						fullName = this.name;
+					} else {
+						fullName = this.ns + "." + this.name;
+					}
+					this.cachedFullName = fullName;
+				}
+				return fullName;
 			}
 		}