Lightweight Labeling Scheme for On-the-fly Race Detection of Signal Handlers

Abstract

Data races represent one of the most notorious class of bugs in shared-memory parallel programs since they are hard to reproduce and can lead programs into unintended nondeterministic executions. However, data races can also show up in sequential programs that use signals when a signal handler and the sequential program both access without proper synchronization, a shared variable with at least one write-access operation. Unfortunately, existing tools for race detection in such programs produce high time and space overhead that drastically slow down the monitored program. This overhead is partly due to the use of costly and inappropriate timestamps originally designed for threads' ordering in multithreaded programs. This paper presents a lightweight labeling scheme for efficient on-the-fly race detection in sequential programs that use signal handlers. This scheme generates constant-sized labels for the program and its signal handlers and determines the logical concurrency between instructions accessing the same shared memory. Generating and comparing concurrency information are done in constant time. The efficiency of the technique and its limited footprint on the program execution make the on-the-fly race detection more practical in sequential programs.