What is the fastest cyclic synchronization in Java (ExecutorService vs. CyclicBarrier vs. X)?

Question

Which Java synchronization construct is likely to provide the best performance for a concurrent, iterative processing scenario with a fixed number of threads like the one outli

Answer 1

Update: V6 - Busy Wait, with main thread also working

An obvious improvement on V5 (busy wait for work in 7 worker threads, busy wait for completion in main thread) seemed to again split the work into 7+1 parts and to let the main thread process one part concurrently with the other worker threads (instead of just busy-waiting), and to subsequently busy-wait for the completion of all other threads' work items. That would utilize the 8th processor (in the example's 8-core configuration) and add its cycles to the available compute resource pool.

This was indeed straight-forward to implement. And the results are indeed again slightly better:

blocksize | system | user | cycles/sec
256k        1.0%     98%       1.39
64k         1.0%     98%       6.8
16k         1.0%     98%      50.4
4096        1.0%     98%     372
1024        1.0%     98%    1317
256         1.0%     98%    3546
64          1.5%     98%    9091
16          2.0%     98%   16949

So this seems to represents the best solution so far.