Reducing State Explosion for Software Model Checking with Relaxed Memory Consistency Models

Abstract

Abstract. Software model checking suffers from the so-called state explosion problem, and relaxed memory consistency models even worsen this situation. What is worse, parameterizing model checking by memory consistency models, that is, to make the model checker as flexible as we can supply definitions of memory consistency models as an input, intensifies state explosion. This paper explores specific reasons for state explosion in model checking with multiple memory consistency models, provides some optimizations intended to mitigate the problem, and applies them to McSPIN, a model checker for memory consistency models that we are developing. The effects of the optimizations and the usefulness of McSPIN are demonstrated experimentally by verifying copying protocols of concurrent copying garbage collection algorithms. To the best of our knowledge, this is the first model checking of the concurrent copying protocols under relaxed memory consistency models.

Heap Fuzzing: Automatic Garbage Collection Testing with Expert-Guided Random Events

“…To understand application allocation patterns, we instrumented all object allocations in 111 example programs. Our 111 programs included synthetic benchmarks, and the entire test suite executions of Pharo's standard library, its IDE, and high-level libraries such as its bytecode compiler and its Roassal3 visualization engine 1 . Such programs represent daily Pharo executions on continuous integration systems.…”

“…It requires the specification of GC semantics as a separate formalism that requires maintenance to stay in sync with the actual implementation. Thus, techniques have been developed to optimize formal approaches [1]. In comparison, our solution trades-off precision for being lightweight to implement, replicate and execute.…”

“…Existing work proposes to perform static verifications of garbage collection (GC) algorithms using theorem This work was funded by Inria -AlaMVic Action Exploratoire provers [13], [27] and model checking [5], [29], [34]. Such approaches are heavy-weight to implement and execute, even at the expense of requiring specific techniques to optimize them [1] (See Section VI).…”