Comprehensive synchronization elimination for Java

AbstractIn this paper, we describe three novel analyses for eliminating unnecessary synchronization that remove over 70% of dynamic synchronization operations on the majority of our 15 benchmarks and improve the bottom-line performance of three by 37–53%. Our whole-program analyses attack three frequent forms of unnecessary synchronization: thread-local synchronization, reentrant synchronization, and enclosed lock synchronization. We motivate the design of our analyses with a study of the kinds of unnecessary synchronization found in a suite of single- and multi-threaded benchmarks of different sizes and drawn from a variety of domains. We analyze the performance of our optimizations in terms of dynamic operations removed and run-time speedup. We also show that our analyses may enable the use of simpler synchronization models than the model found in Java, at little or no additional cost in execution time. The synchronization optimizations, we describe enable programmers to design efficient, reusable and maintainable libraries and systems in Java without cumbersome manual code restructuring

Merlin: A Language for Provisioning Network Resources

This paper presents Merlin, a new framework for managing resources in software-defined networks. With Merlin, administrators express high-level policies using programs in a declarative language. The language includes logical predicates to identify sets of packets, regular expressions to encode forwarding paths, and arithmetic formulas to specify bandwidth constraints. The Merlin compiler uses a combination of advanced techniques to translate these policies into code that can be executed on network elements including a constraint solver that allocates bandwidth using parameterizable heuristics. To facilitate dynamic adaptation, Merlin provides mechanisms for delegating control of sub-policies and for verifying that modifications made to sub-policies do not violate global constraints. Experiments demonstrate the expressiveness and scalability of Merlin on real-world topologies and applications. Overall, Merlin simplifies network administration by providing high-level abstractions for specifying network policies and scalable infrastructure for enforcing them