Functional Programming Perspectives on Concurrency and Parallelism


Matthew Fluet
Toyota Technological Institute
Chicago


The trend in microprocessor design toward multicore processors has
sparked renewed interest in programming languages and language
features for harnessing concurrency and parallelism in commodity
applications.  Past research efforts demonstrated that functional
programming provides a good semantic base for concurrent- and
parallel-language designs, but slowed in the absence of widely
available multiprocessor machines.  I will describe two new functional
programming approaches towards concurrency and parallelism, grounded
in more recent functional programming research.

In the first half of the talk, I will introduce transactional events,
a novel concurrency abstraction that combines first-class synchronous
message-passing events with all-or-nothing transactions.  This
combination enables elegant solutions to interesting problems in
concurrent programming.  Transactional events have a rich
compositional structure, inspired by the use of monads for describing
effectful computations in functional programming.

In the second half of the talk, I will introduce the Manticore
project, an effort to design and implement a new functional language
for parallel programming.  Unlike some earlier parallel language
proposals, Manticore is a heterogenous language that supports
parallelism at multiple levels.  I will describe a number of
Manticore's notable features, including implicitly-parallel
programming constructs (inspired by common functional programming
idioms) and a flexible runtime model that supports multiple scheduling
disciplines.  I'll conclude with future research directions, aiming to
combine static and dynamic information for the implementation and
optimization of parallel constructs.