Software thread level speculation (TLS) solutions tend to mirror the hardware ones, in the sense that they employ one, exact dependency-tracking mechanism. Our perspective is that software-flexibility is, perhaps, better exploited by a family of lighter, if less precise speculative models that can be combined together in an effective configuration, which takes advantage of the application's code-patterns.

This paper reports on two main contributions. First, it introduces SpLSC: a software TLS model that trades the potential for false-positive violations for a small memory overhead and efficient implementation. Second, it presents PolyLibTLS: a library that encapsulates several lightweight models and enables their composition. In this context, we report on the template meta-programming techniques that we used to achieve performance and safety, while preserving library's modularity, extensibility and usability properties.

Furthermore, we demonstrate that the user-framework interaction is straightforward and present parallelization timing results that validate our high-level perspective.