hg: jdk9/hs-rt/hotspot: 8049304: race between VM_Exit and _sync_FutileWakeups->inc()

[daniel.daugherty at oracle.com]

Changeset: f44314157fcb
Author:    dcubed
Date:      2015-09-03 10:22 -0700
URL:       http://hg.openjdk.java.net/jdk9/hs-rt/hotspot/rev/f44314157fcb

8049304: race between VM_Exit and _sync_FutileWakeups->inc()
Summary: Add PerfDataManager.has_PerfData() to indicate when PerfData objects should be safe to query. Update Java monitor PerfData usage to check the new flag. PerfDataManager::destroy() should only be called at a safepoint and when the StatSampler is not active.
Reviewed-by: kbarrett, dholmes, tbenson, bdelsart

! src/share/vm/runtime/objectMonitor.cpp
! src/share/vm/runtime/objectMonitor.hpp
! src/share/vm/runtime/perfData.cpp
! src/share/vm/runtime/perfData.hpp
! src/share/vm/runtime/perfMemory.cpp
! src/share/vm/runtime/synchronizer.cpp