[concurrency-interest] ForkJoinPool does not achieve expected parallelism

Doug Lea dl at cs.oswego.edu
Tue May 22 19:17:50 EDT 2012


On 05/22/12 12:20, Romain Colle wrote:
>

Thanks for the nicely conceived test case!
The problem was lack of a secondary signalling check
(present in previous versions) that isn't now needed
for submissions queues, but sometimes is otherwise.
This is now in updated CVS and jar files.

> I'm not quite sure why the initial "2" was put there.

It allows some parallelization of signalling, by
letting other threads help with wakeups when
they find work.

-Doug


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