A concurrent program debugging environment using real-time replay

A common debugging strategy involves re-execution of a program (on a given input) over and over, each time gaining more information about bugs. Such techniques can fail in concurrent programs. Because of variations in message latencies and process scheduling, different runs on the given input may produce different results. This non-repeatability rules out the reproduction of errors which is the cornerstone of conventional debugging techniques. So, guaranteeing reproducibility is major issue in the concurrent program debugging. This paper discusses the design and implementation of a concurrent program debugging environment which replays the error-occurred execution and debugs the errors using a recorded event history file and input data.