Distributed Debugging With I/O Abstraction

This thesis presents a simple, yet powerful, set of mechanisms for testing and debugging distributed applications consisting of modules that communicate through well-defined data interfaces. The tools allow default or programmer-defined functions to be attached to various communication events so that particular data values at interesting points in the program are made available for testing and debugging. The debugging status of each component of the communication interface can be controlled separately so that various debugging information can be turned on and off during program execution. By attaching breakpoints to programmer-defined fucntions in a standard debugger, fine-grained examination of each module of the applicaton can be integrated with the coarse-grained communication debugging information provided by our tools