X10: an object-oriented approach to non-uniform cluster computing

It is now well established that the device scaling predicted by Moore’s Law is no longer a viable option for increasing the clock frequency of future uniprocessor systems at the rate that had been sustained during the last two decades. As a result, future systems are rapidly moving from uniprocessor to multiprocessor configurations, so as to use parallelism in-stead of frequency scaling as the foundation for increased compute capacity. The dominant emerging multiprocessor structure for the future is a Non-Uniform Cluster Computing (NUCC) system with nodes that are built out of multi-core SMP chips with non-uniform memory hierarchies, and in-terconnected in horizontally scalable cluster configurations such as blade servers. Unlike previous generations of hard-ware evolution, this shift will have a major impact on exist-ing software. Current OO language facilities for concurrent and distributed programming are inadequate for addressing the needs of NUCC systems because they do not support the notions of non-uniform data access within a node, or of tight coupling of distributed nodes. We have designed a modern object-oriented programming language, X10, for high performance, high productivity pro-gramming of NUCC systems. A member of the parti-tioned global address space family of languages, X10 high-lights the explicit reification of locality in the form of places