C# MarshalByRefObject.InitializeLifetimeService方法代码示例

        // Initiates the creation of a lease

        // Creates a sink for invoking a renew on call when an object is created.

        public IMessageSink GetObjectSink(MarshalByRefObject obj, 
                                          IMessageSink nextSink)

        {
            bool fServer;
            ServerIdentity identity = (ServerIdentity)MarshalByRefObject.GetIdentity(obj, out fServer);
            BCLDebug.Assert(identity != null, "[LifetimeServices.GetObjectSink] identity != null");

            // NOTE: Single Call objects do not have a lease associated with it because they last 
            // only for the duration of the call. 
            // Singleton objects on the other hand do have leases associated with them and they can 
            // be garbage collected.
            if (identity.IsSingleCall())
            {
                BCLDebug.Trace("REMOTE", "LeaseLifeTimeServiceProperty.GetObjectSink, no lease SingleCall",obj,", NextSink "+nextSink);                
                return nextSink;
            }
    


            // Create lease. InitializeLifetimeService is a virtual method which can be overridded so that a lease with
            // object specific properties can be created.
            Object leaseObj = obj.InitializeLifetimeService();


            BCLDebug.Trace("REMOTE", "LeaseLifeTimeServiceProperty.GetObjectSink, return from InitializeLifetimeService obj ",obj,", lease ",leaseObj);


            // InitializeLifetimeService can return a lease in one of conditions:
            // 1) the lease has a null state which specifies that no lease is to be created.
            // 2) the lease has an initial state which specifies that InitializeLifeTimeService has created a new lease.
            // 3) the lease has another state which indicates that the lease has already been created and registered.


            if (leaseObj == null)
                {
                    BCLDebug.Trace("REMOTE", "LeaseLifeTimeServiceProperty.GetObjectSink, no lease ",obj,", NextSink "+nextSink);
                    return nextSink;
                }

            if (!(leaseObj is System.Runtime.Remoting.Lifetime.ILease))
                throw new RemotingException(String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("Remoting_Lifetime_ILeaseReturn"), leaseObj));

            ILease ilease = (ILease)leaseObj;
    
            if (ilease.InitialLeaseTime.CompareTo(TimeSpan.Zero) <= 0)
                {
                    // No lease
                    {
                        BCLDebug.Trace("REMOTE", "LeaseLifeTimeServiceProperty.GetObjectSink, no lease because InitialLeaseTime is Zero ",obj);
                        if (ilease is System.Runtime.Remoting.Lifetime.Lease)
                            {
                                ((Lease)ilease).Remove();
                            }
                        return nextSink;
                    }
                }


            Lease lease = null;
            lock(identity)
                {
                    if (identity.Lease != null)
                        {
                            // Lease already exists for object, object is being marsalled again
                            BCLDebug.Trace("REMOTE", "LeaseLifeTimeServiceProperty.GetObjectSink, Lease already exists for object ",obj);                    
                            lease = (Lease)identity.Lease;
                            lease.Renew(lease.InitialLeaseTime); // Reset initial lease time
                        }
                    else
                        {
                            // New lease
                            if (!(ilease is System.Runtime.Remoting.Lifetime.Lease))
                                {
                                    // InitializeLifetimeService created its own ILease object
                                    // Need to create a System.Runtime.Remoting.Lease object
                                    BCLDebug.Trace("REMOTE", "LeaseLifeTimeServiceProperty.GetObjectSink, New Lease, lease not of type Lease  ",obj);                                            
                                    lease = (Lease)LifetimeServices.GetLeaseInitial(obj);
                                    if (lease.CurrentState == LeaseState.Initial)
                                        {
                                            lease.InitialLeaseTime = ilease.InitialLeaseTime;
                                            lease.RenewOnCallTime = ilease.RenewOnCallTime;
                                            lease.SponsorshipTimeout = ilease.SponsorshipTimeout;
                                        }
                                }
                            else
                                {
                                    // An object of Type Lease was created
                                    BCLDebug.Trace("REMOTE", "LeaseLifeTimeServiceProperty.GetObjectSink, New Lease, lease is type Lease  ",obj);                                                                    
                                    lease = (Lease)ilease;
                                }

                            // Put lease in active state
                            // Creation phase of lease is over, properties can no longer be set on lease.
                            identity.Lease = lease; // Place lease into identity for object
                            // If the object has been marshaled activate 
//.........这里部分代码省略.........

 public IMessageSink GetObjectSink(MarshalByRefObject obj, IMessageSink nextSink)
 {
     bool flag;
     ServerIdentity identity = (ServerIdentity) MarshalByRefObject.GetIdentity(obj, out flag);
     if (!identity.IsSingleCall())
     {
         object obj2 = obj.InitializeLifetimeService();
         if (obj2 == null)
         {
             return nextSink;
         }
         if (!(obj2 is ILease))
         {
             throw new RemotingException(Environment.GetResourceString("Remoting_Lifetime_ILeaseReturn", new object[] { obj2 }));
         }
         ILease lease = (ILease) obj2;
         if (lease.InitialLeaseTime.CompareTo(TimeSpan.Zero) <= 0)
         {
             if (lease is Lease)
             {
                 ((Lease) lease).Remove();
             }
             return nextSink;
         }
         Lease leaseInitial = null;
         lock (identity)
         {
             if (identity.Lease != null)
             {
                 leaseInitial = identity.Lease;
                 leaseInitial.Renew(leaseInitial.InitialLeaseTime);
             }
             else
             {
                 if (lease is Lease)
                 {
                     leaseInitial = (Lease) lease;
                 }
                 else
                 {
                     leaseInitial = (Lease) LifetimeServices.GetLeaseInitial(obj);
                     if (leaseInitial.CurrentState == LeaseState.Initial)
                     {
                         leaseInitial.InitialLeaseTime = lease.InitialLeaseTime;
                         leaseInitial.RenewOnCallTime = lease.RenewOnCallTime;
                         leaseInitial.SponsorshipTimeout = lease.SponsorshipTimeout;
                     }
                 }
                 identity.Lease = leaseInitial;
                 if (identity.ObjectRef != null)
                 {
                     leaseInitial.ActivateLease();
                 }
             }
         }
         if (leaseInitial.RenewOnCallTime > TimeSpan.Zero)
         {
             return new LeaseSink(leaseInitial, nextSink);
         }
     }
     return nextSink;
 }