Abstract. This paper demonstrates the impact of integrating session types and object-oriented programming, through their implementation in Java. Session types provide high-level abstraction for structuring a series of interactions in a simple and concise syntax, and ensure type-safe communications between distributed peers. We present the first full implementation of a language and runtime for session-based distributed programming featuring asynchronous message passing, delegation and session subtyping, combined with class downloading and exceptions. The compilation and runtime framework of our language effectively maps session abstraction onto underlying transports and guarantees communication safety through static and dynamic session type checking. We have implemented two alternative protocols for performing correct and efficient session delegation and prove their correctness. Benchmark results show the session abstraction can be realised with minimal runtime overhead. 1

Abstract. This project aims to improve the metaprogramming and verification capabilities of the GNU Compiler Collection. It consists of a plugin infrastructure that exposes two compile-time mechanisms. The first of these is a mechanism by which one may perform arbitrary computations over types within the context of the C++ template metaprogramming infrastructure. The second of these exposes selected portions of the control flow graph and basic block statements of Low GIMPLE, with additional support infrastructure that allows for data-flow analysis of the resultant structure. The plugins themselves are written in Haskell, reflecting the functional nature of both C++ template metaprogramming and standard data-flow analysis. We demonstrate the effectiveness of our technique using specific case studies in the field of session types.

Abstract. This project aims to improve the metaprogramming and verification capabilities of the GNU Compiler Collection. It consists of a plugin infrastructure that exposes two compile-time mechanisms. The first of these is a mechanism by which one may perform arbitrary computations over types within the context of the C++ template metaprogramming infrastructure. The second of these exposes selected portions of the control flow graph and basic block statements of Low GIMPLE, with additional support infrastructure that allows for data-flow analysis of the resultant structure. The plugins themselves are written in Haskell, reflecting the functional nature of both C++ template metaprogramming and standard data-flow analysis. We demonstrate the effectiveness of our technique using specific case studies in the field of session types. Key words: C++, Metaprogramming, Program Analysis

This paper addresses the problem of identifying incompatibilities between two programs that operate in a producer/consumer relationship. It describes the techniques that are incorporated in a tool called PCCA (Producer-Consumer Conformance Analyzer), which attempts to (i) determine whether the consumer is prepared to accept all messages that the producer can emit, or (ii) find a counterexample: a message that the producer can emit and the consumer considers ill-formed.