.NET Remoting Basic(3)-生存期租约

    用于管理远程对象的生命周期

1.初始化租约

使用LifetimeServices对象初始化

static void Main(string[] args)
 {
     Console.WriteLine ("ServerStartup.Main(): Server started");
 
     LifetimeServices.LeaseManagerPollTime = TimeSpan.FromMilliseconds(10);
 
     HttpChannel chnl = new HttpChannel(1234);
     ChannelServices.RegisterChannel(chnl);
 
     RemotingConfiguration.RegisterWellKnownServiceType(
         typeof(MyRemoteFactory),
         "factory.soap",
         WellKnownObjectMode.Singleton);
 
     // the server will keep running until keypress.
     Console.ReadLine();
 }

2.自定义租约

一旦设置，将无法更改

重写 MarshalByRefObject.InitializeLifetimeService()

public override object InitializeLifetimeService() 
 {
     Console.WriteLine("MyRemoteObject.InitializeLifetimeService() called");
     ILease lease = (ILease)base.InitializeLifetimeService();
     if (lease.CurrentState == LeaseState.Initial)  
     {
         lease.InitialLeaseTime = TimeSpan.FromMilliseconds(10);
         lease.SponsorshipTimeout = TimeSpan.FromMilliseconds(10);
         lease.RenewOnCallTime = TimeSpan.FromMilliseconds(10);
     }
     return lease;
 }

3.客户端测试

static void Main(string[] args)
 {
     HttpChannel channel = new HttpChannel();
     ChannelServices.RegisterChannel(channel);
 
           Console.WriteLine("Acqu. Rem. Instance");
                 IRemoteFactory fact = (IRemoteFactory) Activator.GetObject(
             typeof(IRemoteFactory),
             "http://localhost:1234/factory.soap");
     
     Console.WriteLine("Client.Main(): Acquiring object from factory");
     IRemoteObject obj1 = fact.getNewInstance();
 
     Console.WriteLine("Client.Main(): Sleeping one second");
     
     System.Threading.Thread.Sleep(1000);
 
     Console.WriteLine("Client.Main(): Setting value");
     try 
     {
       obj1.setValue(42);
     } 
     catch (Exception e) 
     {
         Console.WriteLine("Client.Main(). EXCEPTION \n{0}",e.Message);
     }
 
     Console.ReadLine();
 }

测试结果

将显示对象过期，抛出错误信息.

4.续订租约

static void Main(string[] args)
 {
 //同上,略  
    IRemoteObject obj1 = fact.getNewInstance();
     ((obj1 as MarshalByRefObject).GetLifetimeService() as ILease).Renew(TimeSpan.FromSeconds(1000));
     Console.WriteLine("Client.Main(): Sleeping one second");
     
     System.Threading.Thread.Sleep(1000);
 //略
 }

测试结果,对象可以照常使用