Refactoring SweepGenerator

- Removed IOrchardShellEvents base interface to prevent every request from
instanciating it (as it would be an event)
- Call ITransactionManager.Demand() before executing tasks or nested
transaction scopes with RequiresNew would fail

--HG--
branch : 1.x

src/Orchard/Environment/DefaultOrchardShell.cs

@@ -5,6 +5,7 @@ using Autofac.Features.OwnedInstances;
 using Orchard.Logging;
 using Orchard.Mvc.ModelBinders;
 using Orchard.Mvc.Routes;
+using Orchard.Tasks;
 using IModelBinderProvider = Orchard.Mvc.ModelBinders.IModelBinderProvider;
 
 namespace Orchard.Environment {
@@ -14,18 +15,21 @@ namespace Orchard.Environment {
         private readonly IRoutePublisher _routePublisher;
         private readonly IEnumerable<IModelBinderProvider> _modelBinderProviders;
         private readonly IModelBinderPublisher _modelBinderPublisher;
+        private readonly ISweepGenerator _sweepGenerator;
 
         public DefaultOrchardShell(
             Func<Owned<IOrchardShellEvents>> eventsFactory,
             IEnumerable<IRouteProvider> routeProviders,
             IRoutePublisher routePublisher,
             IEnumerable<IModelBinderProvider> modelBinderProviders,
-            IModelBinderPublisher modelBinderPublisher) {
+            IModelBinderPublisher modelBinderPublisher,
+            ISweepGenerator sweepGenerator) {
             _eventsFactory = eventsFactory;
             _routeProviders = routeProviders;
             _routePublisher = routePublisher;
             _modelBinderProviders = modelBinderProviders;
             _modelBinderPublisher = modelBinderPublisher;
+            _sweepGenerator = sweepGenerator;
 
             Logger = NullLogger.Instance;
         }
@@ -36,19 +40,23 @@ namespace Orchard.Environment {
             _routePublisher.Publish(_routeProviders.SelectMany(provider => provider.GetRoutes()));
             _modelBinderPublisher.Publish(_modelBinderProviders.SelectMany(provider => provider.GetModelBinders()));
 
+            _sweepGenerator.Activate();
+
             using (var events = _eventsFactory()) {
                 events.Value.Activated();
             }
         }
 
         public void Terminate() {
-            try {
-                using (var events = _eventsFactory()) {
+            using (var events = _eventsFactory()) {
+                try {
                     events.Value.Terminating();
                 }
-            }
-            catch {
-                // ignore exceptions while terminating the application
+                catch {
+                    // ignore exceptions while terminating the application
+                }
+
+                _sweepGenerator.Terminate();
             }
         }
     }

src/Orchard/Tasks/SweepGenerator.cs

@@ -1,11 +1,16 @@
 using System;
 using System.Timers;
 using Orchard.Data;
-using Orchard.Environment;
 using Orchard.Logging;
 
 namespace Orchard.Tasks {
-    public class SweepGenerator : IOrchardShellEvents {
+
+    public interface ISweepGenerator : ISingletonDependency {
+        void Activate();
+        void Terminate();
+    }
+
+    public class SweepGenerator : ISweepGenerator, IDisposable {
         private readonly IWorkContextAccessor _workContextAccessor;
         private readonly Timer _timer;
 
@@ -24,13 +29,13 @@ namespace Orchard.Tasks {
             set { _timer.Interval = value.TotalMilliseconds; }
         }
 
-        public void Activated() {
+        public void Activate() {
             lock (_timer) {
                 _timer.Start();
             }
         }
 
-        public void Terminating() {
+        public void Terminate() {
             lock (_timer) {
                 _timer.Stop();
             }
@@ -56,10 +61,17 @@ namespace Orchard.Tasks {
 
         public void DoWork() {
             using (var scope = _workContextAccessor.CreateWorkContextScope()) {
+                var transactionManager = scope.Resolve<ITransactionManager>();
+                transactionManager.Demand();
+
                 // resolve the manager and invoke it
                 var manager = scope.Resolve<IBackgroundService>();
                 manager.Sweep();
             }
         }
+
+        public void Dispose() {
+            _timer.Dispose();
+        }
     }
 }