Previous efforts at parallelizing dynamic programming have fo cused on the bottomup. We show a method for parallelizing top down dynamic programs in a straightforward way by a careful choice of a lock free shared hash table implementation and randomization of the order in which the dynamic program computes its subproblems. Ia32 intel architecture software developers manual, volume 3. A parallel dynamic programming algorithm, basing on the matrix calculation, is used to develop the optimum energy management strategy for a fuel cell and lithiumion battery hybrid train.
In this paper, we present a new lockfree tree data structure for parallel monte carlo tree search mcts which removes synchronization overhead and. Such a lockfree scheme might appear doomed to fail as processors could overwrite each others progress. Safe memory reclamation for dynamic lockfree objects using atomic reads and writes. Pdf lockfree concurrent data structures semantic scholar. Pdf lockfree programming is a wellknown technique for multithreaded programming. Hogwild a lockfree approach to parallelizing stochastic. We show a method for parallelizing top down dynamic programs in a straightforward way by a careful choice of a lockfree shared hash table implementation.
Lockfree parallel dynamic programming sciencedirect. Iirc, what you typically do with dynamic programming is to recursively divide a problem into subproblems, and assemble optimal solutions from optimal subsolutions. Concurrent programming without locks department of computer. Lockfree dynamically resizable arrays bjarne stroustrups.
Concurrency, lockfree systems, transactional memory. Lockfree parallel dynamic programming journal of parallel and. Concurrent data structures are the data sharing side of parallel programming. Distributed and cloud computing from parallel processing to the internet of things kai hwang geoffrey c. Once a key, value pair has been inserted, any further insertions of the same key. Abstra ct w e study the parallel computation of dynamic programming w e consider four imp ortan t dynamic programming problems whic hha v e wide application. Parallel computing and openmp mit opencourseware free. On practice, parallel programming models must include scalable concurrent. Dynamic programming is an optimization approach that transforms a complex problem into a. Speedup for parallelized dynamic programs using the lock free open addressing hash table on amd quad core opteron 2. By default, the original number of forked threads is used throughout. Your code adds locks around operations 1, 2 get and 5, 6 set, but that does nothing to prevent the problematic sequence of events. However, the commuters are probably not free to arbitrarily choose the. Lockfree concurrent hash tables the hash table needed to implement a topdown dynamic programming approach only requires two operations.
What makes it effective is that all optimal subsolutions are built into a cache so they need not be recomputed. This softwarebased mcas algorithm has been effectively applied. Lockfree parallel dynamic programming archivo digital upm. An implementation of a data structure is called lockfree, if it allows multiple. What you need to do is to lock the whole operation, so that while thread a is incrementing the value, thread b cant access it at all. Parallel programming for multicore machines using openmp and mpi.
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