Abstract

Concurrency bugs are becoming increasingly prevalent in the multi-core era. Recently, much research has focused on data races and atomicity violation bugs, which are related to low-level memory accesses. However, a large number of concurrency typestate bugs such as “invalid reads to a closed file from a different thread” are under-studied. These concurrency typestate bugs are important yet challenging to study since they are mostly relevant to high-level program semantics. This paper presents 2ndStrike, a method to manifest hidden concurrency typestate bugs in software testing. Given a state machine describing correct program behavior on certain object typestates, 2ndStrike profiles runtime events related to the typestates and thread synchronization. Based on the profiling results, 2ndStrike then identifies bug candidates, each of which is a pair of runtime