Decidability Results for Dynamic Installation of Compensation Handlers

Proceedings of the Symposium on Applied Computing

2017

Programming abstractions for compensation handling and dynamic update are crucial in specifying reliable interacting systems, such as Collective Adaptive Systems (CAS). Compensations and updates both specify how a system reacts in response to exceptional events. Prior work showed that different semantics for compensation handling can be encoded into a calculus of adaptable processes with objective updates, in which a process is reconfigured by its context. This paper goes further by considering subjective updates, in which, intuitively, a process reconfigures itself. A calculus of adaptable processes with subjective update its introduced, and its expressivity is assessed by encoding two semantics for compensation handling. The resulting encodings are more efficient than those using objective updates: they require less computational steps.

Section: Compensable Processesmentioning

confidence: 99%

Section: Compensable Processesmentioning

confidence: 99%

“…This preservation is realized by extraction functions, denoted extr(·). For process P , the semantics in [9,10] decree:…”

Section: Compensable Processesmentioning

confidence: 99%

“…Following [9,10], the semantics of compensable processes is given in terms of a Labeled Transition System (LTS). Ranged over by α, α , the set of labels includes a, a and τ.…”

Section: Compensable Processesmentioning

confidence: 99%

See 2 more Smart Citations

Efficient compensation handling via subjective updates

Proceedings of the Symposium on Applied Computing

2017

“…Our core process language with compensations is based on the calculus in [13] (a variant of the language in [12]). The languages in [12,13] are appealing because they uniformly capture several different proposals for calculi with compensation handling. These calculi were introduced as extensions of the π-calculus [16] with primitives for static and dynamic recovery.…”

Section: Adaptable and Compensable Processes By Examplementioning

confidence: 99%

On Compensation Primitives as Adaptable Processes

Electron. Proc. Theor. Comput. Sci.

2015

We compare mechanisms for compensation handling and dynamic update in calculi for concurrency. These mechanisms are increasingly relevant in the specification of reliable communicating systems. Compensations and updates are intuitively similar: both specify how the behavior of a concurrent system changes at runtime in response to an exceptional event. However, calculi with compensations and updates are technically quite different. We investigate the relative expressiveness of these calculi: we develop encodings of core process languages with compensations into a calculus of adaptable processes developed in prior work. Our encodings shed light on the (intricate) semantics of compensation handling and its key constructs. They also enable the transference of existing verification and reasoning techniques for adaptable processes to core languages with compensation handling.

On primitives for compensation handling as adaptable processes

Journal of Logical and Algebraic Methods in Programming

2021

Mechanisms for compensation handling and dynamic update are increasingly relevant in the specification of reliable communicating systems. Compensations and updates are intuitively similar: both specify how the behavior of a concurrent system changes at runtime in response to an exceptional event. However, calculi for concurrency with compensations and updates are technically quite different. We compare calculi for concurrency with compensation handling and dynamic update from the standpoint of their relative expressiveness. We develop two encodings of a process calculus with compensation handling into a calculus of adaptable processes. These encodings differ in the target language considered: the first considers adaptable processes with subjective updates in which, intuitively, a process reconfigures itself; the second considers objective updates in which a process is reconfigured by a process in its context. Our main discovery is that subjective updates are more efficient than objective ones in encoding primitives for compensation handling: the first encoding requires less computational steps than the second one to mimic a single computation step in the source language of compensable processes. Our encodings satisfy strong correctness criteria; they shed light on the intricate semantics of compensation handling.