hg: shenandoah/jdk9/hotspot: Reference processing deadlocks with -ParallelRefProcEnabled

[ashipile at redhat.com]

Changeset: 9e0a0e79a390
Author:    shade
Date:      2017-06-06 13:52 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk9/hotspot/rev/9e0a0e79a390

Reference processing deadlocks with -ParallelRefProcEnabled

! src/share/vm/gc/shenandoah/shenandoahConcurrentMark.cpp
+ test/gc/shenandoah/acceptance/ParallelRefprocSanity.java