Distributed objects and Join methods: Design issues and operational semantics

We introduce DJ# - a language that can be used to program a Peer-to-Peer network using object-oriented techniques and Join methods. The object creation primitive of DJ# has two parameters, a class name and a peer name, allowing the programmer to create instances of any class on any node of the network. In the object-oriented programming spirit, DJ# objects can communicate by sending and receiving messages. As in Join Java or Polyphonic C#, both synchronous and asynchronous messages can be transmitted between distributed objects. The DJ# model provides a form of dynamic connectivity of interacting objects that can use Join methods to implement various communication mechanisms. The paper presents the design rationales and a formal operational semantics for DJ#.