Formal Derivation of Concurrent Garbage Collectors

Concurrent garbage collectors are notoriously difficult to implement correctly. Previous approaches to the issue of producing correct collectors have mainly been based on posit-and-prove verification or on the application of domain-specific templates and transformations. We show how to derive the upper reaches of a family of concurrent garbage collectors by refinement from a formal specification, emphasizing the application of domain-independent design theories and transformations. A key contribution is an extension to the classical lattice-theoretic fixpoint theorems to account for the dynamics of concurrent mutation and collection.Comment: 38 pages, 21 figures. The short version of this paper appeared in the Proceedings of MPC 201

Colimits for Concurrent Collectors

This case study applies techniques of formal program development by specification refinement and composition to the problem of concurrent garbage collection. The specification formalism is mainly based on declarative programming paradigms, the imperative aspect is dealt with by using monads. We also sketch the use of temporal logic in connection with monadic specifications