--- a/src/hotspot/share/gc/z/zRootsIterator.cpp	Thu Oct 17 20:27:44 2019 +0100
+++ b/src/hotspot/share/gc/z/zRootsIterator.cpp	Thu Oct 17 20:53:35 2019 +0100
@@ -30,6 +30,7 @@
 #include "gc/shared/barrierSet.hpp"
 #include "gc/shared/barrierSetNMethod.hpp"
 #include "gc/shared/oopStorageParState.inline.hpp"
+#include "gc/shared/oopStorageSet.hpp"
 #include "gc/shared/suspendibleThreadSet.hpp"
 #include "gc/z/zBarrierSetNMethod.hpp"
 #include "gc/z/zGlobals.hpp"
@@ -43,7 +44,6 @@
 #include "prims/jvmtiExport.hpp"
 #include "prims/resolvedMethodTable.hpp"
 #include "runtime/atomic.hpp"
-#include "runtime/jniHandles.hpp"
 #include "runtime/thread.hpp"
 #include "runtime/safepoint.hpp"
 #include "runtime/synchronizer.hpp"
@@ -69,6 +69,7 @@
 static const ZStatSubPhase ZSubPhaseConcurrentRoots("Concurrent Roots");
 static const ZStatSubPhase ZSubPhaseConcurrentRootsTeardown("Concurrent Roots Teardown");
 static const ZStatSubPhase ZSubPhaseConcurrentRootsJNIHandles("Concurrent Roots JNIHandles");
+static const ZStatSubPhase ZSubPhaseConcurrentRootsVMHandles("Concurrent Roots VMHandles");
 static const ZStatSubPhase ZSubPhaseConcurrentRootsClassLoaderDataGraph("Concurrent Roots ClassLoaderDataGraph");
 
 static const ZStatSubPhase ZSubPhasePauseWeakRootsSetup("Pause Weak Roots Setup");
@@ -170,7 +171,8 @@
   }
 };
 
-ZRootsIterator::ZRootsIterator() :
+ZRootsIterator::ZRootsIterator(bool visit_jvmti_weak_export) :
+    _visit_jvmti_weak_export(visit_jvmti_weak_export),
     _universe(this),
     _object_synchronizer(this),
     _management(this),
@@ -198,7 +200,6 @@
   } else {
     ZNMethod::oops_do_end();
   }
-  JvmtiExport::gc_epilogue();
 
   COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
   Threads::assert_all_threads_claimed();
@@ -232,7 +233,8 @@
 
 void ZRootsIterator::do_system_dictionary(ZRootsIteratorClosure* cl) {
   ZStatTimer timer(ZSubPhasePauseRootsSystemDictionary);
-  SystemDictionary::oops_do(cl);
+  // Handles are processed via _vm_handles.
+  SystemDictionary::oops_do(cl, false /* include_handles */);
 }
 
 void ZRootsIterator::do_threads(ZRootsIteratorClosure* cl) {
@@ -247,7 +249,7 @@
   ZNMethod::oops_do(cl);
 }
 
-void ZRootsIterator::oops_do(ZRootsIteratorClosure* cl, bool visit_jvmti_weak_export) {
+void ZRootsIterator::oops_do(ZRootsIteratorClosure* cl) {
   ZStatTimer timer(ZSubPhasePauseRoots);
   _universe.oops_do(cl);
   _object_synchronizer.oops_do(cl);
@@ -258,29 +260,24 @@
   if (!ClassUnloading) {
     _code_cache.oops_do(cl);
   }
-  if (visit_jvmti_weak_export) {
+  if (_visit_jvmti_weak_export) {
     _jvmti_weak_export.oops_do(cl);
   }
 }
 
-ZConcurrentRootsIterator::ZConcurrentRootsIterator(bool marking) :
-    _marking(marking),
-    _sts_joiner(marking /* active */),
-    _jni_handles_iter(JNIHandles::global_handles()),
+ZConcurrentRootsIterator::ZConcurrentRootsIterator(int cld_claim) :
+    _jni_handles_iter(OopStorageSet::jni_global()),
+    _vm_handles_iter(OopStorageSet::vm_global()),
+    _cld_claim(cld_claim),
     _jni_handles(this),
+    _vm_handles(this),
     _class_loader_data_graph(this) {
   ZStatTimer timer(ZSubPhaseConcurrentRootsSetup);
-  if (_marking) {
-    ClassLoaderDataGraph_lock->lock();
-    ClassLoaderDataGraph::clear_claimed_marks();
-  }
+  ClassLoaderDataGraph::clear_claimed_marks(cld_claim);
 }
 
 ZConcurrentRootsIterator::~ZConcurrentRootsIterator() {
   ZStatTimer timer(ZSubPhaseConcurrentRootsTeardown);
-  if (_marking) {
-    ClassLoaderDataGraph_lock->unlock();
-  }
 }
 
 void ZConcurrentRootsIterator::do_jni_handles(ZRootsIteratorClosure* cl) {
@@ -288,20 +285,21 @@
   _jni_handles_iter.oops_do(cl);
 }
 
+void ZConcurrentRootsIterator::do_vm_handles(ZRootsIteratorClosure* cl) {
+  ZStatTimer timer(ZSubPhaseConcurrentRootsVMHandles);
+  _vm_handles_iter.oops_do(cl);
+}
+
 void ZConcurrentRootsIterator::do_class_loader_data_graph(ZRootsIteratorClosure* cl) {
   ZStatTimer timer(ZSubPhaseConcurrentRootsClassLoaderDataGraph);
-  if (_marking) {
-    CLDToOopClosure cld_cl(cl, ClassLoaderData::_claim_strong);
-    ClassLoaderDataGraph::always_strong_cld_do(&cld_cl);
-  } else {
-    CLDToOopClosure cld_cl(cl, ClassLoaderData::_claim_none);
-    ClassLoaderDataGraph::cld_do(&cld_cl);
-  }
+  CLDToOopClosure cld_cl(cl, _cld_claim);
+  ClassLoaderDataGraph::always_strong_cld_do(&cld_cl);
 }
 
 void ZConcurrentRootsIterator::oops_do(ZRootsIteratorClosure* cl) {
   ZStatTimer timer(ZSubPhaseConcurrentRoots);
   _jni_handles.oops_do(cl);
+  _vm_handles.oops_do(cl),
   _class_loader_data_graph.oops_do(cl);
 }
 
@@ -340,10 +338,10 @@
 }
 
 ZConcurrentWeakRootsIterator::ZConcurrentWeakRootsIterator() :
-    _vm_weak_handles_iter(SystemDictionary::vm_weak_oop_storage()),
-    _jni_weak_handles_iter(JNIHandles::weak_global_handles()),
-    _string_table_iter(StringTable::weak_storage()),
-    _resolved_method_table_iter(ResolvedMethodTable::weak_storage()),
+    _vm_weak_handles_iter(OopStorageSet::vm_weak()),
+    _jni_weak_handles_iter(OopStorageSet::jni_weak()),
+    _string_table_iter(OopStorageSet::string_table_weak()),
+    _resolved_method_table_iter(OopStorageSet::resolved_method_table_weak()),
     _vm_weak_handles(this),
     _jni_weak_handles(this),
     _string_table(this),
@@ -413,26 +411,3 @@
   _string_table.oops_do(cl);
   _resolved_method_table.oops_do(cl);
 }
-
-ZThreadRootsIterator::ZThreadRootsIterator() :
-    _threads(this) {
-  assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
-  ZStatTimer timer(ZSubPhasePauseRootsSetup);
-  Threads::change_thread_claim_token();
-}
-
-ZThreadRootsIterator::~ZThreadRootsIterator() {
-  ZStatTimer timer(ZSubPhasePauseRootsTeardown);
-  Threads::assert_all_threads_claimed();
-}
-
-void ZThreadRootsIterator::do_threads(ZRootsIteratorClosure* cl) {
-  ZStatTimer timer(ZSubPhasePauseRootsThreads);
-  ResourceMark rm;
-  Threads::possibly_parallel_oops_do(true, cl, NULL);
-}
-
-void ZThreadRootsIterator::oops_do(ZRootsIteratorClosure* cl) {
-  ZStatTimer timer(ZSubPhasePauseRoots);
-  _threads.oops_do(cl);
-}