A study of common pitfalls in simple multi-threaded programs

It is generally acknowledged that developing correct multithreaded codes is difficult, because threads may interact with each other in unpredictable ways. The goal of this work is to discover common multi-threaded programming pitfalls, the knowledge of which will be useful in instructing new programmers and in developing tools to aid in multi-threaded programming. To this end, we study multi-threaded applications written by students from introductory operating systems courses. Although the applications are simple, careful inspection and the use of an automatic race detection tool reveal a surprising quantity and variety of synchronization errors. We describe and discuss these errors, evaluate the role of automated tools, and propose new tools for use in the instruction of multi-threaded programming.