Variant-Frequency Semantics for Green Futures

TL;DR

This paper introduces an operational semantics for futures that emphasizes energy efficiency by allowing threads to run at different paces, inspired by dynamic CPU core frequency adjustments, aiming to reduce synchronization costs.

Contribution

It presents a novel semantics that models variant thread frequencies as an integral feature, enabling more energy-efficient concurrent programming.

Findings

The semantics can reduce synchronization energy costs.

It models dynamic frequency adjustments in concurrent threads.

Provides a foundation for future energy-aware language designs.

Abstract

This paper describes an operational semantics for futures, with the primary target on energy efficiency. The work in progress is built around an insight that different threads can coordinate by running at different "paces," so that the time for synchronization and the resulting wasteful energy consumption can be reduced. We exploit several inherent characteristics of futures to determine how the paces of involving threads can be coordinated. The semantics is inspired by recent advances in computer architectures, where the frequencies of CPU cores can be adjusted dynamically. The work is a first-step toward a direction where variant frequencies are directly modeled as an essential semantic feature in concurrent programming languages.