In CustomFJPoolTest#testCustomPools() >> assertEquals(splitsForPC, splitsForPHalfC * 2);
I'm sure I'm slow on the uptake, but isn't this bound to fail for every commonParallelism == 2^n + 1 in the closed range [2, 127], i.e., for 3, 5, 9, 17, 33, 65? Regards, Stefan 2017-11-08 22:01 GMT+01:00 Paul Sandoz <paul.san...@oracle.com>: > Hi, > > Please review this patch to ensure that a parallel stream obeys the > parallelism of a custom fork join pool when it is executed within that pool: > > > http://cr.openjdk.java.net/~psandoz/jdk10/JDK-8190974-par-stream-custom-pool/webrev/ > > <http://cr.openjdk.java.net/~psandoz/jdk10/JDK-8190974-par-stream-custom-pool/webrev/> > > Streams currently do not support capabilities to control the level of > parallelism and therefore resources utilised (tricky API design problem to > get right). > > At the moment the trick is to run stream executions within a custom pool, > however the number of fork join tasks created will be in proportion to the > parallelism of the common pool thus the execution will be over-provisioned. > This can be especially noticeable on large machines with many cores. > > Paul.
