1,350 research outputs found
Correspondence assertions for process synchronization in concurrent communications
High-level specification of patterns of communications such as protocols can be modeled elegantly by means of session types. However, a number of examples suggest that session types fall short when finer precision on protocol specification is required. In order to increase the expressiveness of session types we appeal to the theory of correspondence assertions. The resulting type discipline augments the types of long term channels with effects and thus yields types which may depend on messages read or written earlier within the same session. We prove that evaluation preserves typability and that well-typed processes are safe. Also, we illustrate how the resulting theory allows us to address the shortcomings present in the pure theory of session types.Laboratorio de Investigación y Formación en Informática Avanzad
Correspondence assertions for process synchronization in concurrent communications
High-level specification of patterns of communications such as protocols can be modeled elegantly by means of session types. However, a number of examples suggest that session types fall short when finer precision on protocol specification is required. In order to increase the expressiveness of session types we appeal to the theory of correspondence assertions. The resulting type discipline augments the types of long term channels with effects and thus yields types which may depend on messages read or written earlier within the same session. We prove that evaluation preserves typability and that well-typed processes are safe. Also, we illustrate how the resulting theory allows us to address the shortcomings present in the pure theory of session types.Laboratorio de Investigación y Formación en Informática Avanzad
Correspondence assertions for process synchronization in concurrent communications
High-level specification of patterns of communications such as protocols can be modeled elegantly by means of session types. However, a number of examples suggest that session types fall short when finer precision on protocol specification is required. In order to increase the expressiveness of session types we appeal to the theory of correspondence assertions. The resulting type discipline augments the types of long term channels with effects and thus yields types which may depend on messages read or written earlier within the same session. We prove that evaluation preserves typability and that well-typed processes are safe. Also, we illustrate how the resulting theory allows us to address the shortcomings present in the pure theory of session types.Laboratorio de Investigación y Formación en Informática Avanzad
Regression-free Synthesis for Concurrency
While fixing concurrency bugs, program repair algorithms may introduce new
concurrency bugs. We present an algorithm that avoids such regressions. The
solution space is given by a set of program transformations we consider in for
repair process. These include reordering of instructions within a thread and
inserting atomic sections. The new algorithm learns a constraint on the space
of candidate solutions, from both positive examples (error-free traces) and
counterexamples (error traces). From each counterexample, the algorithm learns
a constraint necessary to remove the errors. From each positive examples, it
learns a constraint that is necessary in order to prevent the repair from
turning the trace into an error trace. We implemented the algorithm and
evaluated it on simplified Linux device drivers with known bugs.Comment: for source code see https://github.com/thorstent/ConRepai
Dynamic Role Authorization in Multiparty Conversations
Protocol specifications often identify the roles involved in communications.
In multiparty protocols that involve task delegation it is often useful to
consider settings in which different sites may act on behalf of a single role.
It is then crucial to control the roles that the different parties are
authorized to represent, including the case in which role authorizations are
determined only at runtime. Building on previous work on conversation types
with flexible role assignment, here we report initial results on a typed
framework for the analysis of multiparty communications with dynamic role
authorization and delegation. In the underlying process model, communication
prefixes are annotated with role authorizations and authorizations can be
passed around. We extend the conversation type system so as to statically
distinguish processes that never incur in authorization errors. The proposed
static discipline guarantees that processes are always authorized to
communicate on behalf of an intended role, also covering the case in which
authorizations are dynamically passed around in messages.Comment: In Proceedings BEAT 2014, arXiv:1408.556
Integrated testing and verification system for research flight software design document
The NASA Langley Research Center is developing the MUST (Multipurpose User-oriented Software Technology) program to cut the cost of producing research flight software through a system of software support tools. The HAL/S language is the primary subject of the design. Boeing Computer Services Company (BCS) has designed an integrated verification and testing capability as part of MUST. Documentation, verification and test options are provided with special attention on real time, multiprocessing issues. The needs of the entire software production cycle have been considered, with effective management and reduced lifecycle costs as foremost goals. Capabilities have been included in the design for static detection of data flow anomalies involving communicating concurrent processes. Some types of ill formed process synchronization and deadlock also are detected statically
Combining behavioural types with security analysis
Today's software systems are highly distributed and interconnected, and they
increasingly rely on communication to achieve their goals; due to their
societal importance, security and trustworthiness are crucial aspects for the
correctness of these systems. Behavioural types, which extend data types by
describing also the structured behaviour of programs, are a widely studied
approach to the enforcement of correctness properties in communicating systems.
This paper offers a unified overview of proposals based on behavioural types
which are aimed at the analysis of security properties
Putting time into proof outlines
A logic for reasoning about timing of concurrent programs is presented. The logic is based on proof outlines and can handle maximal parallelism as well as resource-constrained execution environments. The correctness proof for a mutual exclusion protocol that uses execution timings in a subtle way illustrates the logic in action
PLACES'10: The 3rd Workshop on Programmng Language Approaches to concurrency and Communication-Centric Software
Paphos, Cyprus. March 201
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