Atomics for a Real-time Virtual Machine

January 24, 2006
Jan Vitek | Purdue University

This talk introduces a concurrency control abstraction, called preemptible atomic regions (PARs). PARs are a restricted form of software transactional memory that provide a convincing alternative to mutual exclusion monitors in commodity uniprocessor real-time systems. I will report on the implementation of Real-time Virtual Machine with built-in support for atomicity. The predictability requirements of real-time systems and the rich source language (Java) present a number of challenges for an efficient implementation of atomicity. Furthermore, interoperability with existing code requires smooth integration with existing implementations of monitors that support priority inheritance or priority ceiling emulation. PARs have been evaluated on several real-time programs, including a fielded avionics application. The results show that atomicity can improve the response time of high-priority tasks without noticeably decreasing overall throughput.

Speaker Details

Jan Vitek is a Chief Scientist at Fiji Systems and an Associate Professor of Computer Science at Purdue University. He leads the Ovm real-time virtual machine project. He is a member of the ACM and IFIP WG2.4, a founder of the TRANSACT workshop series, the VEE conference, and the Trends in Concurrency International Summer School series. He sits on steering committee of the ECOOP, COORDINATION and the Java Technologies for Real-time and Embedded System conferences and serves on the JSR302–Safety Critical Java expert group.