Lifestate: Event-Driven Protocols and Callback Control Flow (Artifact)

Developing interactive applications (apps) against event-driven software frameworks such as Android is notoriously difficult. To create apps that behave as expected, developers must follow complex and often implicit asynchronous programming protocols. Such protocols intertwine the proper registering of callbacks to receive control from the framework with appropriate application-programming interface (API) calls that in turn affect the set of possible future callbacks. An app violates the protocol when, for example, it calls a particular API method in a state of the framework where such a call is invalid. What makes automated reasoning hard in this domain is largely what makes programming apps against such frameworks hard: the specification of the protocol is unclear, and the control flow is complex, asynchronous, and higher-order. In this paper, we tackle the problem of specifying and modeling event-driven application-programming protocols. In particular, we formalize a core meta-model that captures the dialogue between event-driven frameworks and application callbacks. Based on this meta-model, we define a language called lifestate that permits precise and formal descriptions of application-programming protocols and the callback control flow imposed by the event-driven framework. Lifestate unifies modeling what app callbacks can expect of the framework with specifying rules the app must respect when calling into the framework. In this way, we effectively combine lifecycle constraints and typestate rules. To evaluate the effectiveness of lifestate modeling, we provide a dynamic verification algorithm that takes as input a trace of execution of an app and a lifestate protocol specification to either produce a trace witnessing a protocol violation or a proof that no such trace is realizable

Using the PALS Architecture to Verify a Distributed Topology Control Protocol for Wireless Multi-Hop Networks in the Presence of Node Failures

The PALS architecture reduces distributed, real-time asynchronous system design to the design of a synchronous system under reasonable requirements. Assuming logical synchrony leads to fewer system behaviors and provides a conceptually simpler paradigm for engineering purposes. One of the current limitations of the framework is that from a set of independent "synchronous machines", one must compose the entire synchronous system by hand, which is tedious and error-prone. We use Maude's meta-level to automatically generate a synchronous composition from user-provided component machines and a description of how the machines communicate with each other. We then use the new capabilities to verify the correctness of a distributed topology control protocol for wireless networks in the presence of nodes that may fail.Comment: In Proceedings RTRTS 2010, arXiv:1009.398

Trial sequential analysis for assessing imprecision in GRADE evaluations – protocol for a methodological study

Abstract Background: Assessing statistical imprecision of summary estimates is an essential element in evaluating the strength of evidence. The GRADE framework recommends assessing imprecision by confidence intervals (CI) in relation to thresholds of interest and in selected cases to assess the relationship between the acquired information size and the calculated optimal information size (OIS). Trial sequential analysis (TSA) calculates multiplicity-adjusted confidence intervals and can be used to calculate a required information size. In a recent methodological study of 544 systematic reviews and meta-analysis reports of clinical trials with TSA, we gathered data regarding the methods used for grading imprecision, specifically regarding the impact of TSA (the METSA project). The questions regarding GRADE imprecision were initially superficially defined and were substantialized only during the project and in the preparations for this protocol. With this add-on study, we investigate the methods of grading imprecision in the GRADE framework by authors of systematic reviews and meta-analysis reports of clinical trials with TSA. Methods: The outlined methodological study will be pre-planned but designed with knowledge about existing but not yet reviewed data on the study questions. The METSA project was not initially designed for the questions raised in the current study protocol, which warrants a critical review of the collected data. We aim to improve precision and accuracy of the collected data regarding imprecision methodology by a redesign of selected data fields, adding new data fields to the data extraction form and a subsequent revision of the existing data extraction accordingly. For each individual study, we will extract or review data regarding the specified methodology including methods for calculating CI and OIS, and thresholds of interest (definitions of important benefit and/or harm). For each topic, we will assess completeness in transparency of described methods and protocolisation, including coherence with the protocol (if relevant). Results: We will report frequencies of observed methods, lack of transparency, and protocolisation. From data gathered in the METSA project, we will report the proportion of imprecision assessments that may have differed in their conclusions if the results of the TSA had been used. Informed by our findings, we will outline new suggestions on how to grade imprecision using TSA. Conclusion: This protocol outlines a methodological study of methods and reporting characteristics imprecision assessment within the GRADE framework in recent systematic reviews and meta-analysis reports of clinical trials utilising trial sequential analysis

Impact of multimorbidity count on all-cause mortality and glycaemic outcomes in people with type 2 diabetes: a systematic review protocol

Introduction: Type 2 diabetes (T2D) is a leading health priority worldwide. Multimorbidity (MM) is a term describing the co-occurrence of two or more chronic diseases or conditions. The majority of people living with T2D have MM. The relationship between MM and mortality and glycaemia in people with T2D is not clear. Methods and analysis: Medline, Embase, Cumulative Index of Nursing and Allied Health Complete, The Cochrane Library, and SCOPUS will be searched with a prespecified search strategy. The searches will be limited to quantitative empirical studies in English with no restriction on publication date. One reviewer will perform title screening and two review authors will independently screen the abstract and full texts using Covidence software, with disagreements adjudicated by a third reviewer. Data will be extracted using a using a Population, Exposure, Comparator and Outcomes framework. Two reviewers will independently extract data and undertake the risk of bias (quality) assessment. Disagreements will be resolved by consensus. A narrative synthesis of the results will be conducted and meta-analysis considered if appropriate. Quality appraisal will be undertaken using the Newcastle-Ottawa quality assessment scale and the quality of the cumulative evidence of the included studies will be assessed using the Grading of Recommendations, Assessment, Development and Evaluation approach. This protocol was prepared in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines to ensure the quality of our review. Ethics and dissemination: This review will synthesise the existing evidence about the impact of MM on mortality and glycaemic outcomes in people living with T2D and increase our understanding of this subject and will inform future practice and policy. Findings will be disseminated via conference presentations, social media and peer-reviewed publication

Noise and Cognitive Performance in Developing Brain using Functional MRI: A scoping review protocol

This protocol aims to guide the process to conduct a scoping review on noise and cognitive performance in developing the brain using functional MRI. This review benefits future research by providing a clear mapping of evidence. This protocol adhered to Arksey and O'Malley's scoping review methodological framework. A Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) extension for Scoping Reviews (PRISMA-ScR) was implemented to report the full scoping review. This protocol facilitated a well-structured mapping of evidence. The findings from scoping review will be made public through conferences and journal publications. Keywords: Scoping review protocol; Adolescents’ cognitive performance; Noise; functional MRI. eISSN: 2398-4287 © 2022. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians/Africans/Arabians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v7i19.325