Multiverse Debugging: Non-Deterministic Debugging for Non-Deterministic Programs (Brave New Idea Paper)

Carmen Torres Lopez, Robbert Gurdeep Singh, Stefan Marr, Elisa Gonzalez Boix, Christophe Scholliers, Michael Wagner
2019 European Conference on Object-Oriented Programming  
Many of today's software systems are parallel or concurrent. With the rise of Node.js and more generally event-loop architectures, many systems need to handle concurrency. However, its nondeterministic behavior makes it hard to reproduce bugs. Today's interactive debuggers unfortunately do not support developers in debugging non-deterministic issues. They only allow us to explore a single execution path. Therefore, some bugs may never be reproduced in the debugging session, because the right
more » ... ditions are not triggered. As a solution, we propose multiverse debugging, a new approach for debugging non-deterministic programs that allows developers to observe all possible execution paths of a parallel program and debug it interactively. We introduce the concepts of multiverse breakpoints and stepping, which can halt a program in different execution paths, i.e. universes. We apply multiverse debugging to AmbientTalk, an actor-based language, resulting in Voyager, a multiverse debugger implemented on top of the AmbientTalk operational semantics. We provide a proof of non-interference, i.e., we prove that observing the behavior of a program by the debugger does not affect the behavior of that program and vice versa. Multiverse debugging establishes the foundation for debugging non-deterministic programs interactively, which we believe can aid the development of parallel and concurrent systems. ACM Subject Classification Software and its engineering → Concurrent programming languages; Software and its engineering → Software testing and debugging
doi:10.4230/lipics.ecoop.2019.27 dblp:conf/ecoop/LopezSMBS19 fatcat:7b5k34sografbhtkduvu2t6twu