An Asynchronous Multithreaded Algorithm for the Maximum Network Flow Problem with Nonblocking Global Relabeling Heuristic

作者：Hong Bo^*; He Zhengyu

来源：IEEE Transactions on Parallel and Distributed Systems, 2011, 22(6): 1025-1033.

DOI：10.1109/TPDS.2010.156

• Maximum network flow
• parallel algorithm
• multithreading
• lock-free

In this paper, we present a novel asynchronous multithreaded algorithm for the maximum network flow problem. The algorithm is based on the classical push-relabel algorithm, which is essentially sequential and requires intensive and costly lock usages to parallelize it. The novelty of the algorithm is in the removal of lock and barrier usages, thereby enabling a much more efficient multithreaded implementation. The newly designed push and relabel operations are executed completely asynchronously and each individual process/thread independently decides when to terminate itself. We further propose an asynchronous global relabeling heuristic to speed up the algorithm. We prove that our algorithm finds a maximum flow with O(vertical bar V vertical bar(2) vertical bar vertical bar E vertical bar) operations, where vertical bar V vertical bar is the number of vertices and vertical bar E vertical bar is the number of edges in the graph. We also prove the correctness of the relabeling heuristic. Extensive experiments show that our algorithm exhibits better scalability and faster execution speed than the lock-based parallel push-relabel algorithm.

• 出版日期2011-6