diff -r 6ca3526c4e25 -r aee0d296c0ef src/hotspot/share/gc/shenandoah/shenandoahRootProcessor.hpp
--- a/src/hotspot/share/gc/shenandoah/shenandoahRootProcessor.hpp	Mon Jun 24 15:19:11 2019 +0100
+++ b/src/hotspot/share/gc/shenandoah/shenandoahRootProcessor.hpp	Mon Jun 24 11:46:46 2019 -0400
@@ -29,11 +29,7 @@
 #include "gc/shenandoah/shenandoahCodeRoots.hpp"
 #include "gc/shenandoah/shenandoahHeap.hpp"
 #include "gc/shenandoah/shenandoahPhaseTimings.hpp"
-#include "gc/shared/strongRootsScope.hpp"
-#include "gc/shared/weakProcessor.hpp"
-#include "gc/shared/weakProcessorPhaseTimes.hpp"
-#include "gc/shared/workgroup.hpp"
-#include "memory/allocation.hpp"
+#include "gc/shenandoah/shenandoahSharedVariables.hpp"
 #include "memory/iterator.hpp"
 
 class ShenandoahSerialRoot {
@@ -61,10 +57,102 @@
   void oops_do(OopClosure* cl, uint worker_id);
 };
 
+class ShenandoahWeakSerialRoot {
+  typedef void (*WeakOopsDo)(BoolObjectClosure*, OopClosure*);
+private:
+  ShenandoahSharedFlag                      _claimed;
+  const WeakOopsDo                          _weak_oops_do;
+  const ShenandoahPhaseTimings::GCParPhases _phase;
+
+public:
+  ShenandoahWeakSerialRoot(WeakOopsDo oops_do, ShenandoahPhaseTimings::GCParPhases);
+  void weak_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id);
+};
+
+#if INCLUDE_JVMTI
+class ShenandoahJVMTIWeakRoot : public ShenandoahWeakSerialRoot {
+public:
+  ShenandoahJVMTIWeakRoot();
+};
+#endif // INCLUDE_JVMTI
+
+#if INCLUDE_JFR
+class ShenandoahJFRWeakRoot : public ShenandoahWeakSerialRoot {
+public:
+  ShenandoahJFRWeakRoot();
+};
+#endif // INCLUDE_JFR
+
+class ShenandoahSerialWeakRoots {
+private:
+  JVMTI_ONLY(ShenandoahJVMTIWeakRoot _jvmti_weak_roots;)
+  JFR_ONLY(ShenandoahJFRWeakRoot     _jfr_weak_roots;)
+public:
+  void weak_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, uint worker_id);
+  void weak_oops_do(OopClosure* cl, uint worker_id);
+};
+
+template <bool CONCURRENT>
+class ShenandoahWeakRoot {
+private:
+  OopStorage::ParState<CONCURRENT, false /* is_const */> _itr;
+  const ShenandoahPhaseTimings::GCParPhases _phase;
+public:
+  ShenandoahWeakRoot(OopStorage* storage, ShenandoahPhaseTimings::GCParPhases phase);
+
+  template <typename Closure>
+  void oops_do(Closure* cl, uint worker_id);
+};
+
+template <>
+class ShenandoahWeakRoot<false /*concurrent*/> {
+private:
+  OopStorage::ParState<false /*concurrent*/, false /*is_const*/> _itr;
+  const ShenandoahPhaseTimings::GCParPhases _phase;
+
+public:
+  ShenandoahWeakRoot(OopStorage* storage, ShenandoahPhaseTimings::GCParPhases phase);
+
+  template <typename IsAliveClosure, typename KeepAliveClosure>
+  void weak_oops_do(IsAliveClosure* is_alive, KeepAliveClosure* keep_alive, uint worker_id);
+};
+
+template <bool CONCURRENT>
+class ShenandoahWeakRoots {
+private:
+  ShenandoahWeakRoot<CONCURRENT>  _jni_roots;
+  ShenandoahWeakRoot<CONCURRENT>  _string_table_roots;
+  ShenandoahWeakRoot<CONCURRENT>  _resolved_method_table_roots;
+  ShenandoahWeakRoot<CONCURRENT>  _vm_roots;
+
+public:
+  ShenandoahWeakRoots();
+
+  template <typename Closure>
+  void oops_do(Closure* cl, uint worker_id = 0);
+};
+
+template <>
+class ShenandoahWeakRoots<false /*concurrent */> {
+private:
+  ShenandoahWeakRoot<false /*concurrent*/>  _jni_roots;
+  ShenandoahWeakRoot<false /*concurrent*/>  _string_table_roots;
+  ShenandoahWeakRoot<false /*concurrent*/>  _resolved_method_table_roots;
+  ShenandoahWeakRoot<false /*concurrent*/>  _vm_roots;
+public:
+  ShenandoahWeakRoots();
+
+  template <typename Closure>
+  void oops_do(Closure* cl, uint worker_id = 0);
+
+  template <typename IsAliveClosure, typename KeepAliveClosure>
+  void weak_oops_do(IsAliveClosure* is_alive, KeepAliveClosure* keep_alive, uint worker_id);
+};
+
 template <bool CONCURRENT>
 class ShenandoahJNIHandleRoots {
 private:
-  OopStorage::ParState<CONCURRENT, false /* is_const */> _itr;
+  OopStorage::ParState<CONCURRENT, false /*is_const*/> _itr;
 public:
   ShenandoahJNIHandleRoots();
 
@@ -83,18 +171,6 @@
   void threads_do(ThreadClosure* tc, uint worker_id);
 };
 
-class ShenandoahWeakRoots {
-private:
-  WeakProcessorPhaseTimes _process_timings;
-  WeakProcessor::Task     _task;
-public:
-  ShenandoahWeakRoots(uint n_workers);
-  ~ShenandoahWeakRoots();
-
-  template <typename IsAlive, typename KeepAlive>
-  void oops_do(IsAlive* is_alive, KeepAlive* keep_alive, uint worker_id);
-};
-
 class ShenandoahStringDedupRoots {
 public:
   ShenandoahStringDedupRoots();
@@ -183,7 +259,8 @@
   ShenandoahJNIHandleRoots<false /*concurrent*/>            _jni_roots;
   ShenandoahClassLoaderDataRoots<false /*single threaded*/> _cld_roots;
   ShenandoahThreadRoots                                     _thread_roots;
-  ShenandoahWeakRoots                                       _weak_roots;
+  ShenandoahSerialWeakRoots                                 _serial_weak_roots;
+  ShenandoahWeakRoots<false /*concurrent*/>                 _weak_roots;
   ShenandoahStringDedupRoots                                _dedup_roots;
   ShenandoahCodeCacheRoots<ShenandoahCsetCodeRootsIterator> _code_roots;
   bool                                                      _include_concurrent_roots;
@@ -201,7 +278,8 @@
   ShenandoahJNIHandleRoots<false /*concurrent*/>            _jni_roots;
   ShenandoahClassLoaderDataRoots<false /*single threaded*/> _cld_roots;
   ShenandoahThreadRoots                                     _thread_roots;
-  ShenandoahWeakRoots                                       _weak_roots;
+  ShenandoahSerialWeakRoots                                 _serial_weak_roots;
+  ShenandoahWeakRoots<false /*concurrent*/>                 _weak_roots;
   ShenandoahStringDedupRoots                                _dedup_roots;
   ShenandoahCodeCacheRoots<ShenandoahCsetCodeRootsIterator> _code_roots;
   const bool                                                _update_code_cache;
@@ -220,7 +298,8 @@
   ShenandoahJNIHandleRoots<false /*concurrent*/>            _jni_roots;
   ShenandoahClassLoaderDataRoots<false /*single threaded*/> _cld_roots;
   ShenandoahThreadRoots                                     _thread_roots;
-  ShenandoahWeakRoots                                       _weak_roots;
+  ShenandoahSerialWeakRoots                                 _serial_weak_roots;
+  ShenandoahWeakRoots<false /*concurrent*/>                 _weak_roots;
   ShenandoahStringDedupRoots                                _dedup_roots;
   ShenandoahCodeCacheRoots<ShenandoahAllCodeRootsIterator>  _code_roots;