Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/DynamicModuleRegistry.cs

@@ -0,0 +1,65 @@
+//------------------------------------------------------------------------------
+// <copyright file="DynamicModuleRegistry.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+//------------------------------------------------------------------------------
+
+namespace System.Web {
+    using System;
+    using System.Collections.Generic;
+    using System.Globalization;
+
+    internal sealed class DynamicModuleRegistry {
+
+        private const string _moduleNameFormat = "__DynamicModule_{0}_{1}";
+
+        private readonly List<DynamicModuleRegistryEntry> _entries = new List<DynamicModuleRegistryEntry>();
+        private bool _entriesReadonly;
+        private readonly object _lockObj = new object();
+
+        public void Add(Type moduleType) {
+            if (moduleType == null) {
+                throw new ArgumentNullException("moduleType");
+            }
+            if (!typeof(IHttpModule).IsAssignableFrom(moduleType)) {
+                string message = String.Format(CultureInfo.CurrentCulture, SR.GetString(SR.DynamicModuleRegistry_TypeIsNotIHttpModule), moduleType);
+                throw new ArgumentException(message, "moduleType");
+            }
+
+            lock (_lockObj) {
+                if (_entriesReadonly) {
+                    // modules have already been initialized, e.g. Application_Start has already run
+                    throw new InvalidOperationException(SR.GetString(SR.DynamicModuleRegistry_ModulesAlreadyInitialized));
+                }
+
+                _entries.Add(new DynamicModuleRegistryEntry(MakeUniqueModuleName(moduleType), moduleType.AssemblyQualifiedName));
+            }
+        }
+
+        public ICollection<DynamicModuleRegistryEntry> LockAndFetchList() {
+            lock (_lockObj) {
+                // once the list has been returned, it must be immutable
+                _entriesReadonly = true;
+                return _entries;
+            }
+        }
+
+        private static string MakeUniqueModuleName(Type moduleType) {
+            // returns a unique name for this module
+            return String.Format(CultureInfo.InvariantCulture, _moduleNameFormat, moduleType.AssemblyQualifiedName, Guid.NewGuid());
+        }
+
+    }
+
+    internal struct DynamicModuleRegistryEntry {
+
+        public readonly string Name;
+        public readonly string Type;
+
+        public DynamicModuleRegistryEntry(string name, string type) {
+            Name = name;
+            Type = type;
+        }
+
+    }
+}