Æliens

reactor pattern

• activate handlers when events occur
• allow events from multiple sources
• in single threaded process

See D.C. Schmidt, Using Design Patterns to Develop Reusable Object-oriented Communication Software, CACM October '95, 38(10): 65-74

consequences

• modularity
• configurability of event-driven software
• decoupling application-independent mechanisms from application-specific processing policies
• improves portability -- abstracts from OS
• course grained concurrency control

disadvantages

• handlers are not pre-empted
• flow of control is event-driven
• applications can be hard to debug

applications

• (X) Windows, Interviews, hush
• Orbacus Omnibroker

related patterns

• Observer, Facade, Template Method