Complex software systems are composed of interacting components. These components collaborate to implement abstractions, such as "packets" in a networking system or "virtual memory page" in a virtual memory system. This pattern focuses on organizing the communication infrastructure used by the components, so that communicating components can be added or removed with minimal changes. At the same time, the communication overhead is minimized. 1 Intent Structure inter-component communication in a system so that loosely coupled components make minimal assumptions about the communication infrastructure, while tightly coupled components localize their interactions. 2 Motivation To motivate the pattern, consider the implementation of networking systems and virtual memory systems. Networking systems are typically implemented as subsystems "layered" on top of one another. In this case, the individual layers are our components, and they operate on a single logical resource, the packet. We are...

If an object oriented program is a collection of communicating objects, then the objects' protocols define the languages the program speaks. Unfortunately, protocols are difficult to design in isolation, so many programs' protocols are not as well designed as they could be. This paper presents six patterns which describe how objects protocols can be designed or redesigned. By using these patterns, programs and designs can be made more simple, more general, and more easy to change. Introduction Object's protocols, also know as interfaces, are very important in object oriented design. An object's protocol is the face the object presents to other objects surrounding it. Using an object's protocol, other objects in the program can use the object as a server, thus accessing the behaviour the object provides. Similarly, an object can act as a client to other objects, in turn using their protocols to access their services. This paper presents six patterns for designing object oriented protoc...

Complex software systems are composed of interacting components. These components collaborate to implement abstractions, such as "packets" in a networking system or "virtual memory page" in a virtual memory system. This pattern focuses on organizing the communication infrastructure used by the components, so that communicating components can be added or removed with minimal changes. At the same time, the communication overhead is minimized. 1 Intent Structure inter-component communication in a system so that loosely coupled components make minimal assumptions about the communication infrastructure, while tightly coupled components localize their interactions. 2 Motivation To motivate the pattern, consider the implementation of networking systems and virtual memory systems. Networking systems are typically implemented as subsystems "layered" on top of one another. In this case, the individual layers are our components, and they operate on a single logical resource, the packet. We are...