1 VERIFYING NETWORKS WITH SYMBOLIC EXECUTION Symbolic execution is a promising approach to network veri cation [5, 6]. Inspired from software veri cation where it is mainly used to generate test-cases (e.g. [1]), symbolic execution is a technique for exploring all viable execution paths of a program. Symbolic execution runs programs with symbolic inputs instead of concrete ones. Such an input m...

Understanding a program from its execution traces is extremely difficult because a trace consists of thousands to millions of events, such as method calls, object creation and destruction, etc. Nonetheless, execution traces can provide valuable information, once abstracted from their low-level events. We propose to identify feature-level phases based on events collected from traces of the progr...

Software model checking tools based on a Counterexample Guided Abstraction Refinement (CEGAR) framework have attained considerable success in limited domains. However, scaling these approaches to larger programs with more complex data structures and initialization behavior has proven difficult. Explicit-state model checkers making use of states and operational semantics closely related to actua...

Program analysis has a long history in computer science. Even when only considering the important aspect of termination analysis, in the past decades an overwhelming number of different techniques has been developed. While the programming languages considered by these approaches initially were more of theoretical importance than of practical use, recently also automated analyses for imperative ...

Detecting and predicting a program's execution phases is crucial to dynamically adaptable systems and dynamic optimizations. Program execution phases have a strong connection to program control structures, in particular, loops and procedure calls. Intuitively, a phase can be associated with some dynamic code regions that are embedded in loops and procedures. This paper proposes off-line and on-...

Programming is a demanding task with an education program that requires the assistance of complex tools such as programming environments, algorithm animators, problem graders, etc. In this chapter, we give a comprehensive presentation of tools for program execution and visualization on the Web. We summarize the technical evolution of these tools, describe educational uses, report lessons learne...