Abstract:
An important feature of the Java language is that it provides built-in support for multithreaded programming. In particular, a simplified implementation of the monitor construct, which we refer to as Java monitor, is provided to facilitate thread synchronization. In a Java program, a Java monitor is defined as a Java class that contains one or more synchronized methods, i.e., methods whose signatures contain the keyword synchronized. Unlike a regular object, which is accessed by at most one thread at a time, a Java monitor object is intended to be accessed by multiple threads simultaneously. Thus, testing a Java monitor is significantly different from testing a regular class.

In this talk, we will present a state exploration-based approach to testing Java monitors. A novel aspect of our approach is that during state exploration, threads are introduced on-the-fly, and as needed, to simulate race conditions that can occur when multiple threads try to access a monitor object at the same time. The states and state transitions in the state space of a Java monitor are defined such that thread interactions along each explored path can be precisely captured and controlled. We will report a prototype tool, called MonitorExplorer, and several case studies. The preliminary results indicate that our approach can be very effective in detecting synchronization faults in a Java monitor. We will conclude this talk by highlighting some challenges and opportunities in concurrency testing.

Bio:
Yu Lei is currently an Assistant Professor of Computer Science at the University of Texas, Arlington. He received his Ph.D. degree in Computer Science from North Carolina State Univ. in 2002. He was a Member of Technical Staff in Fujitsu Network Communications, Inc. from 1998 to 2001. His research interests are in the area of automated software analysis, testing and verification. His research has been supported by NASA and NIST.