RequestResourceTracker

using System.Collections.Generic;

    internal static class RequestResourceTracker {
        private static readonly object _resourcesKey = new object();

        private static List<SecureWeakReference> GetResources(HttpContextBase context) {
            var resources = (List<SecureWeakReference>)context.Items[_resourcesKey];
            if (resources == null) {
                resources = new List<SecureWeakReference>();
                context.Items[_resourcesKey] = resources;
            }

            return resources;
        }

        internal static void DisposeResources(HttpContextBase context) {
            var resources = GetResources(context);
            if (resources != null) {
                resources.ForEach(resource => resource.Dispose());
                resources.Clear();
            }
        }

        internal static void RegisterForDispose(HttpContextBase context, IDisposable resource) {
            var resources = GetResources(context);
            if (resources != null) {
                resources.Add(new SecureWeakReference(resource));
            }
        }

        internal static void RegisterForDispose(IDisposable resource) {
            var context = HttpContext.Current;
            if (context != null) {
                RegisterForDispose(new HttpContextWrapper(context), resource);
            }
        }

        private sealed class SecureWeakReference {
            private readonly WeakReference _reference;
            public SecureWeakReference(IDisposable reference) {
                _reference = new WeakReference(reference);
            }

            internal void Dispose() {
                var disposable = (IDisposable)_reference.Target;
                if (disposable != null) {
                    disposable.Dispose();
                }
            }
        }
    }