TinyOS CSE466 Final Project Presentation Group members: Iliana Avila-Campillo Jason Dougherty Sze Ying Kong

Motivation Real-time w/ high level of concurrency High level of modularity Low power consumption Limited memory and CPU speed

Network Sensor Processor Application Active Messaging Component Sonar App_init Processor One instance of OS Application Sonar_start_read Sonar_read_done Active Messaging Component Sonar Component Echo (from HW)

Component Frame Command Handler A Command Handler B Task A Task C Commands Signals Command Handler A Command Handler B Frame Task A Task C Event Handler A Task B Task D Event Handler B Commands Events

Frames One per component Fixed size – allocated at compile time Persists across commands, events, tasks Stores state for component

Tasks Scheduled by OS Run to completion May be pre-empted by events (interrupts) Operate on frames Perform intensive computation

Event Handlers Respond to events – HW or SW Must execute quickly Operate on frames May post tasks May call commands May signal events

Commands Must execute reasonably quickly Operate on frames May call other commands May post tasks May NOT signal events

Implementation OS is comprised of a scheduler and some macros Scheduler is implemented as a circular FIFO queue Posting a task is effected by passing a function pointer to the OS

Implementation – 2 Component interface (events, commands) is described in a *.comp file Perl script generates a C header file from component file Component is implemented in a C source file OS and components are built together

Implementation – 3 Interconnections between components are described in *.desc files A Perl script generates a top-level header file from all description files A Java program uses all description files to generate a C file which performs the dynamic event dispatch

Larry’s Objectives Macros for use with static verification tools (not yet implemented, according to their slides) Run-time checking – none Exception Handling – none Semantic Checking – none