Compositional Reasoning for Explicit Resource Management in Channel-Based Concurrency

We define a pi-calculus variant with a costed semantics where channels are treated as resources that must explicitly be allocated before they are used and can be deallocated when no longer required. We use a substructural type system tracking permission transfer to construct coinductive proof techniques for comparing behaviour and resource usage efficiency of concurrent processes. We establish full abstraction results between our coinductive definitions and a contextual behavioural preorder describing a notion of process efficiency w.r.t. its management of resources. We also justify these definitions and respective proof techniques through numerous examples and a case study comparing two concurrent implementations of an extensible buffer.Comment: 51 pages, 7 figure

A hybrid type system for lock-freedom of mobile processes

We propose a type system for lock-freedom in the π-calculus, which guarantees that certain communications will eventually succeed. Distinguishing features of our type system are: it can verify lock-freedom of concurrent programs that have sophisticated recursive communication structures; it can be fully automated; it is hybrid, in that it combines a type system for lock-freedom with local reasoning about deadlockfreedom, termination, and confluence analyses. Moreover, the type system is parameterized by deadlock-freedom/termination/confluence analyses, so that any methods (e.g. type systems and model checking) can be used for those analyses. A lock-freedom analysis tool has been implemented based on the proposed type system, and tested for non-trivial programs

Slicing of Concurrent Programs and its Application to Information Flow Control

This thesis presents a practical technique for information flow control for concurrent programs with threads and shared-memory communication. The technique guarantees confidentiality of information with respect to a reasonable attacker model and utilizes program dependence graphs (PDGs), a language-independent representation of information flow in a program

A capability calculus for concurrency and determinism

Abstract. We present a capability calculus for checking partial confluence of channel-communicating concurrent processes. Our approach automatically detects more programs to be partially confluent than previous approaches and is able to handle a mix of different kinds of communication channels, including shared reference cells.