19 research outputs found
A declarative approach to heterogeneous multi-mode modelling languages
This paper proposes a declarative approach to multi-mode heterogeneous DSLs based on term rewriting. The paper presents a data model and algorithm for processing syntax structures. It has been validated by an implementation that supports a range of languages. The paper includes an example language that supports both game construction and execution
A declarative approach to heterogeneous multi-mode modelling languages
This paper proposes a declarative approach to multi-mode heterogeneous DSLs based on term rewriting. The paper presents a data model and algorithm for processing syntax structures. It has been validated by an implementation that supports a range of languages. The paper includes an example language that supports both game construction and execution
Multiparty Languages: The Choreographic and Multitier Cases (Pearl)
Choreographic languages aim to express multiparty communication protocols, by providing primitives that make interaction manifest. Multitier languages enable programming computation that spans across several tiers of a distributed system, by supporting primitives that allow computation to change the location of execution. Rooted into different theoretical underpinnings - respectively process calculi and lambda calculus - the two paradigms have been investigated independently by different research communities with little or no contact. As a result, the link between the two paradigms has remained hidden for long.
In this paper, we show that choreographic languages and multitier languages are surprisingly similar. We substantiate our claim by isolating the core abstractions that differentiate the two approaches and by providing algorithms that translate one into the other in a straightforward way. We believe that this work paves the way for joint research and cross-fertilisation among the two communities
Multiparty Languages: The Choreographic and Multitier Cases
International audienceChoreographic languages aim to express multiparty communication protocols, by providing primitives that make interaction manifest. Multitier languages enable programming computation that spans across several tiers of a distributed system, by supporting primitives that allow computation to change the location of execution. Rooted into different theoretical underpinnings-respectively process calculi and lambda calculus-the two paradigms have been investigated independently by different research communities with little or no contact. As a result, the link between the two paradigms has remained hidden for long. In this paper, we show that choreographic languages and multitier languages are surprisingly similar. We substantiate our claim by isolating the core abstractions that differentiate the two approaches and by providing algorithms that translate one into the other in a straightforward way. We believe that this work paves the way for joint research and cross-fertilisation among the two communities
Cautiously Optimistic Program Analyses for Secure and Reliable Software
Modern computer systems still have various security and reliability vulnerabilities. Well-known dynamic analyses solutions can mitigate them using runtime monitors that serve as lifeguards. But the additional work in enforcing these security and safety properties incurs exorbitant performance costs, and such tools are rarely used in practice. Our work addresses this problem by constructing a novel technique- Cautiously Optimistic Program Analysis (COPA).
COPA is optimistic- it infers likely program invariants from dynamic observations, and assumes them in its static reasoning to precisely identify and elide wasteful runtime monitors. The resulting system is fast, but also ensures soundness by recovering to a conservatively optimized analysis when a likely invariant rarely fails at runtime. COPA is also cautious- by carefully restricting optimizations to only safe elisions, the recovery is greatly simplified. It avoids unbounded rollbacks upon recovery, thereby enabling analysis for live production software.
We demonstrate the effectiveness of Cautiously Optimistic Program Analyses in three areas:
Information-Flow Tracking (IFT) can help prevent security breaches and information leaks. But they are rarely used in practice due to their high performance overhead (>500% for web/email servers). COPA dramatically reduces this cost by eliding wasteful IFT monitors to make it practical (9% overhead, 4x speedup).
Automatic Garbage Collection (GC) in managed languages (e.g. Java) simplifies programming tasks while ensuring memory safety. However, there is no correct GC for weakly-typed languages (e.g. C/C++), and manual memory management is prone to errors that have been exploited in high profile attacks. We develop the first sound GC for C/C++, and use COPA to optimize its performance (16% overhead).
Sequential Consistency (SC) provides intuitive semantics to concurrent programs that simplifies reasoning for their correctness. However, ensuring SC behavior on commodity hardware remains expensive. We use COPA to ensure SC for Java at the language-level efficiently, and significantly reduce its cost (from 24% down to 5% on x86).
COPA provides a way to realize strong software security, reliability and semantic guarantees at practical costs.PHDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/170027/1/subarno_1.pd
Modular implicits
We present modular implicits, an extension to the OCaml language for ad-hoc
polymorphism inspired by Scala implicits and modular type classes. Modular
implicits are based on type-directed implicit module parameters, and elaborate
straightforwardly into OCaml's first-class functors. Basing the design on
OCaml's modules leads to a system that naturally supports many features from
other languages with systematic ad-hoc overloading, including inheritance,
instance constraints, constructor classes and associated types
Spray: programming with a persistent distributed heap
We introduce a programming paradigm for distributed applications based on a persistent distributed heap. A proof-of-concept implementation is provided as a Javascript library, together with several examples that embody popular patterns for web applications