Why Programs Fail, 2nd Edition

CHAPTER 8 Observing Facts

Although deduction techniques do not take concrete runs into account, observation determines facts about what has happened in a concrete run. In this chapter, we look under the hood of the actual program execution and introduce widespread techniques for examining program executions and program states. These techniques include classical logging, interactive debuggers, and postmortem debugging, as well as eye-opening visualization and summarization techniques.

8.1 OBSERVING STATE

Deduction alone, as discussed in Chapter 7 is good for telling what might happen. To find out what is actually happening in a concrete failing run, though, we cannot rely on deduction alone. We must take a look at the actual facts—that is, ...