Concurrencer: a tool for retrofitting concurrency into sequential Java applications via concurrent libraries

Abstract

Parallelizing existing sequential programs to run efficiently on multicores is hard. The Java 5 package java.util.concurrent (j.u.c.) supports writing concurrent programs. To use this package, programmers still need to refactor existing code. This is tedious, error-prone, and omission-prone. This demo presents our tool, CONCURRENCER, which enables programmers to refactor sequential code into parallel code that uses j.u.c. concurrent utilities. CONCURRENCER does not require any program annotations, although the transformations span several, non-adjacent, program statements and use custom program analysis. A find-and-replace tool can not perform such transformations. Empirical evaluation shows that CONCURRENCER refactors code effectively: CONCURRENCER correctly identifies and applies transformations that some open-source developers overlooked, and the converted code exhibits good speedup.