ImplementationTechniques.ppt

Implementing Pipe and Filter Lunar Lander * Software Architecture: Foundations, Theory, and Practice; Richard N. Taylor, Nenad Medvidovic, and Eric M. Dashofy; (C) 2008 John Wiley Sons, Inc. Reprinted with permission. Implementing Pipe and Filter Lunar Lander * Implementing Pipe and Filter Lunar Lander * Software Architecture: Foundations, Theory, and Practice; Richard N. Taylor, Nenad Medvidovic, and Eric M. Dashofy; (C) 2008 John Wiley Sons, Inc. Reprinted with permission. Implementing Pipe and Filter Lunar Lander * Takeaways java.io provides a number of useful facilities Stream objects (System.in, System.out) Buffering wrappers OS provides some of the facilities Pipes Concurrency support Note that this version of the application would not work if it operated in batch-sequential mode We had other communication mechanisms available, but did not use them to conform to the PF style We had to develop a new (albeit simple) protocol to get the correct behavior * Implementing Lunar Lander in C2 Framework: LightweightC2 framework Each component has itsown thread of control Components receiverequests or notificationsand respond with newones Message routing followsC2 rules This is a real-time, clock-driven version of Lunar Lander * Software Architecture: Foundations, Theory, and Practice; Richard N. Taylor, Nenad Medvidovic, and Eric M. Dashofy; (C) 2008 John Wiley Sons, Inc. Reprinted with permission. Implementing Lunar Lander in C2 (cont’d) First: Clock component Sends out a ‘tick’ notificationperiodically Does not respond to anymessages * Software Architecture: Foundations, Theory, and Practice; Richard N. Taylor, Nenad Medvidovic, and Eric M. Dashofy; (C) 2008 John Wiley Sons, Inc. Reprinted with permission. Clock Component * import c2.framework.*; public class Clock extends ComponentThread{ public Clock(){ super.create(clock, FIFOPort.class); } public void start(){ super.start(); Thread clockThread = new Thread(){ public v