Keynote: Event Driven Software Quality

Summary form only given. Event-driven programming has found pervasive acceptance, from high-performance servers to embedded systems, as an efficient method for interacting with a complex world. The fastest research Web servers are event- driven, as is the most common operating system for sensor nodes. An event-driven program handles concurrent logical tasks using a cooperative, application-level scheduler. The application developer separates each logical task into event handlers; the scheduler runs multiple handlers in an interleaved fashion. Unfortunately, the loose coupling of the event handlers obscures the program's control flow and makes dependencies hard to express and detect, leading to subtle bugs. As a result, event-driven programs can be difficult to understand, making them hard to debug, maintain, extend, and validate. This talk presents recent approaches to event-driven software quality based on static analysis and testing, along with some open problems. We will discuss progress on how to avoid buffer overflow in TCP servers, stack overflow and missed deadlines in microcontrollers, and rapid battery drain in sensor networks. Our work is part of the Event Driven Software Quality project at UCLA, which is aimed at building the next generation of language and tool support for event-driven programming.