Violation Witnesses and Result Validation for Multi-Threaded Programs

Invariants and error traces are important results of a program analysis, and therefore, a standardized exchange format for verification witnesses is used by many program analyzers to store and share those results. This way, information about program traces and variable assignments can be shared across tools, e.g., to validate verification results, or provided to users, e.g., to visualize and explore the results in order to fix bugs or understand the reason for a program’s correctness. The standard format for correctness and violation witnesses that was used by SV-COMP for several years was only applicable to sequential (single-threaded) programs. To enable the validation of results for multi-threaded programs, we extend the existing standard exchange format by adding information about thread management and thread interleaving. We contribute a reference implementation of a validator for violation witnesses in the new format, which we implemented as component of the software-verification framework "Image missing" . We experimentally evaluate the format and validator on a large set of violation witnesses. The outcome is promising: several verification tools already produce violation witnesses that help validating the verification results, and our witness validator can re-verify most of the produced witnesses.

Nerds: A Case Study Of The PC Industry

This paper discusses the use of a PBS video, Triumph of the Nerds, as a video case study of the personal computer industry. The program traces the birth of the microcomputer industry through interviews with the founders of the industry, including Bill Gates, Paul Allen, Steve Jobs and Gordon Moore. The video is more than an entertaining look at the personal computer industry, but also provides numerous lessons on topics such as protecting intellectual property, strategic alliances, disruptive innovations, competitive strategy, marketing and entrepreneurship.