Understanding Turn Models For Adaptive Routing: The Modular Approach

Routing algorithms were extensively studied first in multi-computer systems, then in multi- and many-core architectures. Among the commonly used routing techniques, the turn model seems the most promising solution when targeting adaptiveness. Based on the turn model, several alternative approaches with different turn prohibition schemes were proposed. This paper gives a new theoretical background for designing deadlock-free partially adaptive logic-based distributed routing algorithms that arc based on the turn model. Two properties are presented, including a necessary and sufficient condition to prove that a routing algorithm is deadlock-free as long as turn restrictions follow a modular distribution. Existing approaches can be considered a subset of the solution space identified by this work. Finally, we propose a novel routing algorithm exhibiting encouraging performance improvements over state-of-the-art approaches.