We believe that embracing nondeterminism and harnessing emergence have great potential to simplify the task of programming manycore processors. To that end, we have designed and implemented Ly, pronounced “Lee”, a new parallel programming language built around two new concepts: (i) ensembles which provide for parallel execution and replace all collections and (ii) iterators, and adverbs, which modify the parallel behavior of messages sent to ensembles. The broad issues around programming in this fashion still need investigation, but, after our initial Ly programming experience, we have identified some specific issues that must be addressed in integrating these concepts into an object-based language, including empty ensembles, partial message understanding, non-local returns from ensemble members, and unintended ensembles.
By: David Ungar; Sam S. Adams
Published in: RC25036 in 2010
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