What is marshaling and what are different kinds of marshaling ?

Marshaling is used when an object is converted so that it can be sent across the network or across application domains. Unmarshaling creates an object from the marshaled data.
There are two ways to do marshaling :-

• Marshal-by-value (MBV) :- In this the object is serialized into the channel, and a copy of the object is created on the other side of the network. The object to marshal is stored into a stream, and the stream is used to build a copy of the object on the other side with the unmarshalling sequence.


• Marshaling-by-reference (MBR):- Here it creates a proxy on the client that is used to communicate with the remote object. The marshaling sequence of a remote object creates an ObjRef instance that itself can be serialized across the network.

Objects that are derived from “MarshalByRefObject” are always marshaled by reference. All our previous samples have classes inherited from “MarshalByRefObject”.

To marshal a remote object the static method RemotingServices.Marshal() is used. RemotingServices.Marshal() has following overloaded versions:-

public static ObjRef Marshal(MarshalByRefObject obj)
public static ObjRef Marshal(MarshalByRefObject obj, string objUri)
public static ObjRef Marshal(MarshalByRefObject obj, string objUri,Type requestedType)

The first argument obj specifies the object to marshal. The objUri is the path that is stored within the marshaled object reference; it can be used to access the remote object. The requestedType can be used to pass a different type of the object to the object reference. This is useful if the client using the remote object shouldn't use the object class but an interface that the remote object class implements instead. In this scenario the interface is the requestedType that should be used for marshaling.

Can Non-Default constructors be used with Single Call SAO?

Twist :- What are the limitation of constructors for Single call SAO ?

Non-Default constructors can not be used with single call objects as object is created with every method call, there is no way to define Non-default constructors in method calls.

It’s possible to use Non-Default constructor with Client activated objects as both methods :-

“NEW” keyword and “Activator.CreateInstance” provide a way to specify Non-Default constructors.

How can we call methods in remoting Asynchronously ?

All previous examples are a synchronous method calls that means client has to wait until the method completes the process. By using Delegates we can make Asynchronous method calls.

What is Asynchronous One-Way Calls ?

One-way calls are a different from asynchronous calls from execution angle that the .NET Framework does not guarantee their execution. In addition, the methods used in this kind of call cannot have return values or out parameters. One-way calls are defined by using [OneWay()] attribute in class.