Facilities/DynamicLoader/Castle.Facilities.DynamicLoader/DynamicLoaderActivator.cs

   1 // Copyright 2004-2008 Castle Project - http://www.castleproject.org/
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 namespace Castle.Facilities.DynamicLoader
  16 {
  17         using System;
  18         using System.Runtime.Remoting;
  19         using System.Runtime.Remoting.Lifetime;
  20         using Castle.Core;
  21         using Castle.MicroKernel;
  22         using Castle.MicroKernel.ComponentActivator;
  23         using Castle.MicroKernel.Facilities;
  24
  25         /// <summary>
  26         /// Delegates the creation of components to a <see cref="RemoteLoader"/>,
  27         /// which creates the component on a different <see cref="AppDomain"/>.
  28         /// </summary>
  29         public class DynamicLoaderActivator : DefaultComponentActivator, IDisposable
  30         {
  31                 private readonly RemoteLoader loader;
  32                 private ClientSponsor keepAliveSponsor;
  33                 private TimeSpan sponsorTimeout = TimeSpan.FromMinutes(2);
  34
  35                 /// <summary>
  36                 /// Creates a new <see cref="DynamicLoaderActivator"/>.
  37                 /// </summary>
  38                 public DynamicLoaderActivator(ComponentModel model, IKernel kernel, ComponentInstanceDelegate onCreation,
  39                                               ComponentInstanceDelegate onDestruction)
  40                         : base(model, kernel, onCreation, onDestruction)
  41                 {
  42                         if (!model.Implementation.IsSubclassOf(typeof(MarshalByRefObject)))
  43                                 throw new FacilityException(
  44                                         String.Format(
  45                                                 "The implementation for the component '{0}' must inherit from System.MarshalByRefObject in order to be created in an isolated AppDomain.",
  46                                                 model.Name));
  47
  48                         this.loader = (RemoteLoader) model.ExtendedProperties["dynamicLoader.loader"];
  49
  50                         if (this.loader == null)
  51                                 throw new FacilityException(String.Format("A remote loader was not created for component '{0}'.", model.Name));
  52                 }
  53
  54                 /// <summary>
  55                 /// Creates the component instance by calling the <see cref="RemoteLoader.CreateRemoteInstance"/>
  56                 /// method. The component is then registered with the <see cref="ClientSponsor"/>
  57                 /// with a renewal time of 2 minutes, in order to stay alive forever.
  58                 /// </summary>
  59                 protected override object CreateInstance(CreationContext context, object[] arguments, Type[] signature)
  60                 {
  61                         object instance = loader.CreateRemoteInstance(Model, context, arguments, signature);
  62
  63                         if (keepAliveSponsor == null)
  64                                 keepAliveSponsor = new ClientSponsor(sponsorTimeout);
  65
  66                         MarshalByRefObject mbro = (MarshalByRefObject) instance;
  67                         ILease lease = (ILease) RemotingServices.GetLifetimeService(mbro);
  68                         if (lease != null)
  69                         {
  70                                 lease.Register(keepAliveSponsor);
  71                                 lease.Renew(sponsorTimeout);
  72                         }
  73
  74                         return instance;
  75                 }
  76
  77                 /// <summary>
  78                 /// Disposes an object, and unregisters it from the <see cref="ClientSponsor"/>.
  79                 /// </summary>
  80                 /// <param name="instance">The object being destroyed</param>
  81                 public override void Destroy(object instance)
  82                 {
  83                         if (instance is IDisposable)
  84                                 ((IDisposable) instance).Dispose();
  85
  86                         if (keepAliveSponsor != null)
  87                                 keepAliveSponsor.Unregister((MarshalByRefObject) instance);
  88                 }
  89
  90                 /// <summary>
  91                 /// Closes the <see cref="ClientSponsor"/> used to keep remote objects alive.
  92                 /// </summary>
  93                 public void Dispose()
  94                 {
  95                         if (keepAliveSponsor != null)
  96                                 keepAliveSponsor.Close();
  97                 }
  98         }
  99 }