A data race detection system is described which precisely identifies data races in concurrent programs. The system and techniques described utilize locksets to maintain information while searching through executions of a concurrent program. The locksets are updated according to program statements in the concurrent program. The dynamic updating of the locksets, combined with a less conservative approach then used in existing lockset data race detection techniques, allows the technique to be precise; that is, the technique does not report false positives when searching a program.