European Conference on Object-Oriented Programming最新文献

Morpheus: Automated Safety Verification of Data-dependent Parser Combinator Programs Morpheus:数据依赖解析器组合程序的自动安全验证

European Conference on Object-Oriented Programming Pub Date : 2023-05-13 DOI: 10.48550/arXiv.2305.07901

Ashish Mishra, S. Jagannathan

{"title":"Morpheus: Automated Safety Verification of Data-dependent Parser Combinator Programs","authors":"Ashish Mishra, S. Jagannathan","doi":"10.48550/arXiv.2305.07901","DOIUrl":"https://doi.org/10.48550/arXiv.2305.07901","url":null,"abstract":"Parser combinators are a well-known mechanism used for the compositional construction of parsers, and have shown to be particularly useful in writing parsers for rich grammars with data-dependencies and global state. Verifying applications written using them, however, has proven to be challenging in large part because of the inherently effectful nature of the parsers being composed and the difficulty in reasoning about the arbitrarily rich data-dependent semantic actions that can be associated with parsing actions. In this paper, we address these challenges by defining a parser combinator framework called Morpheus equipped with abstractions for defining composable effects tailored for parsing and semantic actions and a rich specification language used to define safety properties over the constituent parsers comprising a program. Even though its abstractions yield many of the same expressivity benefits as other parser combinator systems, Morpheus is carefully engineered to yield a substantially more tractable automated verification pathway. We demonstrate its utility in verifying a number of realistic, challenging parsing applications, including several cases that involve non-trivial data-dependent relations.","PeriodicalId":172012,"journal":{"name":"European Conference on Object-Oriented Programming","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116134809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Designing Asynchronous Multiparty Protocols with Crash-Stop Failures 设计具有崩溃停止故障的异步多方协议

European Conference on Object-Oriented Programming Pub Date : 2023-05-10 DOI: 10.48550/arXiv.2305.06238

Adam D. Barwell, P. Hou, N. Yoshida, F. Zhou

{"title":"Designing Asynchronous Multiparty Protocols with Crash-Stop Failures","authors":"Adam D. Barwell, P. Hou, N. Yoshida, F. Zhou","doi":"10.48550/arXiv.2305.06238","DOIUrl":"https://doi.org/10.48550/arXiv.2305.06238","url":null,"abstract":"Session types provide a typing discipline for message-passing systems. However, most session type approaches assume an ideal world: one in which everything is reliable and without failures. Yet this is in stark contrast with distributed systems in the real world. To address this limitation, we introduce Teatrino, a code generation toolchain that utilises asynchronous multiparty session types (MPST) with crash-stop semantics to support failure handling protocols. We augment asynchronous MPST and processes with crash handling branches. Our approach requires no user-level syntax extensions for global types and features a formalisation of global semantics, which captures complex behaviours induced by crashed/crash handling processes. The sound and complete correspondence between global and local type semantics guarantees deadlock-freedom, protocol conformance, and liveness of typed processes in the presence of crashes. Our theory is implemented in the toolchain Teatrino, which provides correctness by construction. Teatrino extends the Scribble multiparty protocol language to generate protocol-conforming Scala code, using the Effpi concurrent programming library. We extend both Scribble and Effpi to support crash-stop behaviour. We demonstrate the feasibility of our methodology and evaluate Teatrino with examples extended from both session type and distributed systems literature.","PeriodicalId":172012,"journal":{"name":"European Conference on Object-Oriented Programming","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125900082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Asynchronous Multiparty Session Type Implementability is Decidable - Lessons Learned from Message Sequence Charts 异步多方会话类型的可实现性是可决定的——从消息序列图中学到的教训

European Conference on Object-Oriented Programming Pub Date : 2023-02-22 DOI: 10.48550/arXiv.2302.11272

Felix Stutz

{"title":"Asynchronous Multiparty Session Type Implementability is Decidable - Lessons Learned from Message Sequence Charts","authors":"Felix Stutz","doi":"10.48550/arXiv.2302.11272","DOIUrl":"https://doi.org/10.48550/arXiv.2302.11272","url":null,"abstract":"Multiparty session types (MSTs) provide efficient means to specify and verify asynchronous message-passing systems. For a global type, which specifies all interactions between roles in a system, the implementability problem asks whether there are local specifications for all roles such that their composition is deadlock-free and generates precisely the specified executions. Decidability of the implementability problem is an open question. We answer it positively for global types with sender-driven choice, which allow a sender to send to different receivers upon branching and a receiver to receive from different senders. To achieve this, we generalise results from the domain of high-level message sequence charts (HMSCs). This connection also allows us to comprehensively investigate how HMSC techniques can be adapted to the MST setting. This comprises techniques to make the problem algorithmically more tractable as well as a variant of implementability that may open new design space for MSTs. Inspired by potential performance benefits, we introduce a generalisation of the implementability problem that we, unfortunately, prove to be undecidable.","PeriodicalId":172012,"journal":{"name":"European Conference on Object-Oriented Programming","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125111830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Multi-graded Featherweight Java 多级轻量级Java

European Conference on Object-Oriented Programming Pub Date : 2023-02-15 DOI: 10.48550/arXiv.2302.07782

Riccardo Bianchini, Francesco Dagnino, P. Giannini, E. Zucca

引用次数: 2

Exact Separation Logic: Towards Bridging the Gap Between Verification and Bug-Finding 精确分离逻辑:弥合验证和bug发现之间的鸿沟

European Conference on Object-Oriented Programming Pub Date : 2022-08-15 DOI: 10.4230/LIPIcs.ECOOP.2023.19

Petar Maksimovic, Caroline Cronjäger, Andreas Lööw, Julian Sutherland, Philippa Gardner

{"title":"Exact Separation Logic: Towards Bridging the Gap Between Verification and Bug-Finding","authors":"Petar Maksimovic, Caroline Cronjäger, Andreas Lööw, Julian Sutherland, Philippa Gardner","doi":"10.4230/LIPIcs.ECOOP.2023.19","DOIUrl":"https://doi.org/10.4230/LIPIcs.ECOOP.2023.19","url":null,"abstract":"Over-approximating (OX) program logics, such as separation logic (SL), are used for verifying properties of heap-manipulating programs: all terminating behaviour is characterised, but established results and errors need not be reachable. OX function specifications are thus incompatible with true bug-finding supported by symbolic execution tools such as Pulse and Pulse-X. In contrast, under-approximating (UX) program logics, such as incorrectness separation logic, are used to find true results and bugs: established results and errors are reachable, but there is no mechanism for understanding if all terminating behaviour has been characterised. We introduce exact separation logic (ESL), which provides fully-verified function specifications compatible with both OX verification and UX true bug-funding: all terminating behaviour is characterised, and all established results and errors are reachable. We prove soundness for ESL with mutually recursive functions, demonstrating, for the first time, function compositionality for a UX logic. We show that UX program logics require subtle definitions of internal and external function specifications compared with the familiar definitions of OX logics. We investigate the expressivity of ESL and, for the first time, explore the role of abstraction in UX reasoning by verifying abstract ESL specifications of various data-structure algorithms. In doing so, we highlight the difference between abstraction (hiding information) and over-approximation (losing information). Our findings demonstrate that, expectedly, abstraction cannot be used as freely in UX logics as in OX logics, but also that it should be feasible to use ESL to provide tractable function specifications for self-contained, critical code, which would then be used for both verification and true bug-finding.","PeriodicalId":172012,"journal":{"name":"European Conference on Object-Oriented Programming","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129171274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

VeriFx: Correct Replicated Data Types for the Masses VeriFx:为质量正确复制数据类型

European Conference on Object-Oriented Programming Pub Date : 2022-07-06 DOI: 10.48550/arXiv.2207.02502

Kevin De Porre, Carla Ferreira, E. G. Boix

{"title":"VeriFx: Correct Replicated Data Types for the Masses","authors":"Kevin De Porre, Carla Ferreira, E. G. Boix","doi":"10.48550/arXiv.2207.02502","DOIUrl":"https://doi.org/10.48550/arXiv.2207.02502","url":null,"abstract":"Distributed systems adopt weak consistency to ensure high availability and low latency, but state convergence is hard to guarantee due to conflicts. Experts carefully design replicated data types (RDTs) that resemble sequential data types and embed conflict resolution mechanisms that ensure convergence. Designing RDTs is challenging as their correctness depends on subtleties such as the ordering of concurrent operations. Currently, researchers manually verify RDTs, either by paper proofs or using proof assistants. Unfortunately, paper proofs are subject to reasoning flaws and mechanized proofs verify a formalisation instead of a real-world implementation. Furthermore, writing mechanized proofs is reserved to verification experts and is extremely time consuming. To simplify the design, implementation, and verification of RDTs, we propose VeriFx, a high-level programming language with automated proof capabilities. VeriFx lets programmers implement RDTs atop functional collections and express correctness properties that are verified automatically. Verified RDTs can be transpiled to mainstream languages (currently Scala or JavaScript). VeriFx also provides libraries for implementing and verifying Conflict-free Replicated Data Types (CRDTs) and Operational Transformation (OT) functions. These libraries implement the general execution model of those approaches and define their correctness properties. We use the libraries to implement and verify an extensive portfolio of 35 CRDTs and reproduce a study on the correctness of OT functions.","PeriodicalId":172012,"journal":{"name":"European Conference on Object-Oriented Programming","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130897451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Maniposynth: Bimodal Tangible Functional Programming Maniposynth:双峰有形函数式编程

European Conference on Object-Oriented Programming Pub Date : 2022-06-30 DOI: 10.4230/LIPIcs.ECOOP.2022.16

Brian Hempel, Ravi Chugh

{"title":"Maniposynth: Bimodal Tangible Functional Programming","authors":"Brian Hempel, Ravi Chugh","doi":"10.4230/LIPIcs.ECOOP.2022.16","DOIUrl":"https://doi.org/10.4230/LIPIcs.ECOOP.2022.16","url":null,"abstract":"Traditionally, writing code is a non-graphical, abstract, and linear process. Not everyone is comfortable with this way of thinking at all times. Can programming be transformed into a graphical, concrete, non-linear activity? While nodes-and-wires and blocks-based programming environments do leverage graphical direct manipulation, users perform their manipulations on abstract syntax tree elements, which are still abstract. Is it possible to be more concrete - could users instead directly manipulate live program values to create their program? We present a system, Maniposynth, that reimagines functional programming as a non-linear workflow where program expressions are spread on a 2D canvas. The live results of those expressions are continuously displayed and available for direct manipulation. The non-linear canvas liberates users to work out-of-order, and the live values can be interacted with via drag-and-drop. Incomplete programs are gracefully handled via hole expressions, which allow Maniposynth to offer program synthesis. Throughout the workflow, the program is valid OCaml code which the user may inspect and edit in their preferred text editor at any time. With Maniposynth's direct manipulation features, we created 38 programs drawn from a functional data structures course. We additionally hired two professional OCaml developers to implement a subset of these programs. We report on these experiences and discuss to what degree Maniposynth meets its goals of providing a non-linear, concrete, graphical programming workflow.","PeriodicalId":172012,"journal":{"name":"European Conference on Object-Oriented Programming","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116671610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Hinted Dictionaries: Efficient Functional Ordered Sets and Maps 暗示字典:有效的功能有序集和映射

European Conference on Object-Oriented Programming Pub Date : 2022-06-09 DOI: 10.48550/arXiv.2206.04380

A. Shaikhha, Mahdi Ghorbani, Hesam Shahrokhi

引用次数: 3

Fair Termination of Multiparty Sessions 公平终止多党会议

European Conference on Object-Oriented Programming Pub Date : 2022-05-18 DOI: 10.48550/arXiv.2205.08786

L. Ciccone, Francesco Dagnino, L. Padovani

引用次数: 2

Static Analysis for AWS Best Practices in Python Code Python代码中AWS最佳实践的静态分析

European Conference on Object-Oriented Programming Pub Date : 2022-05-09 DOI: 10.48550/arXiv.2205.04432

Rajdeep Mukherjee, Omer Tripp, B. Liblit, Michael Wilson

{"title":"Static Analysis for AWS Best Practices in Python Code","authors":"Rajdeep Mukherjee, Omer Tripp, B. Liblit, Michael Wilson","doi":"10.48550/arXiv.2205.04432","DOIUrl":"https://doi.org/10.48550/arXiv.2205.04432","url":null,"abstract":"Amazon Web Services (AWS) is a comprehensive and broadly adopted cloud provider, offering over 200 fully featured services, including compute, database, storage, networking and content delivery, machine learning, Internet of Things and many others. AWS SDKs provide access to AWS services through API endpoints. However, incorrect use of these APIs can lead to code defects, crashes, performance issues, and other problems. This paper presents automated static analysis rules, developed in the context of a commercial service for detection of code defects and security vulnerabilities, to identify deviations from AWS best practices in Python applications that use the AWS SDK. Such applications use the AWS SDK for Python, called\"Boto3\", to access AWS cloud services. However, precise static analysis of Python applications that use cloud SDKs requires robust type inference for inferring the types of cloud service clients. The dynamic style of Boto3 APIs poses unique challenges for type resolution, as does the interprocedural style in which service clients are used in practice. In support of our best-practices goal, we present a layered strategy for type inference that combines multiple type-resolution and tracking strategies in a staged manner. From our experiments across>3,000 popular Python GitHub repos that make use of the AWS SDK, our layered type inference system achieves 85% precision and 100% recall in inferring Boto3 clients in Python client code. Additionally, we present a representative sample of eight AWS best-practice rules that detect a wide range of issues including pagination, polling, and batch operations. We have assessed the efficacy of these rules based on real-world developer feedback. Developers have accepted more than 85% of the recommendations made by five out of eight Python rules, and almost 83% of all recommendations.","PeriodicalId":172012,"journal":{"name":"European Conference on Object-Oriented Programming","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122496331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6