--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shared/oopStorageSet.hpp	Wed Aug 21 18:42:30 2019 -0400
@@ -0,0 +1,184 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_GC_SHARED_OOPSTORAGESET_HPP
+#define SHARE_GC_SHARED_OOPSTORAGESET_HPP
+
+#include "memory/allocation.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/macros.hpp"
+
+class OopStorage;
+
+class OopStorageSet : public AllStatic {
+private:
+  friend void oopstorage_init();
+
+  enum {
+    singular_index,             // For singular iterator.
+
+    all_start,
+
+    // Strong
+    strong_start = all_start,
+    jni_global_index = strong_start,
+    vm_global_index,
+    strong_end,
+
+    // Weak
+    weak_start = strong_end,
+    jni_weak_index = weak_start,
+    vm_weak_index,
+    string_table_weak_index,
+    resolved_method_table_weak_index,
+    weak_end,
+
+    all_end = weak_end
+  };
+
+  static OopStorage* storages[all_end];
+
+  static void verify_initialized(uint index) NOT_DEBUG_RETURN;
+
+  static OopStorage* storage(uint index) {
+    verify_initialized(index);
+    return storages[index];
+  }
+
+  static void initialize();
+
+public:
+  class Iterator;
+
+  static const uint strong_count = (strong_end - strong_start);
+  static const uint weak_count = (weak_end - weak_start);
+  static const uint all_count = (all_end - all_start);
+
+  static Iterator strong_iterator();
+  static Iterator weak_iterator();
+  static Iterator all_iterator();
+
+  // Strong
+  static OopStorage* jni_global() { return storage(jni_global_index); }
+  static OopStorage* vm_global()  { return storage(vm_global_index); }
+
+  // Weak
+  static OopStorage* jni_weak()   { return storage(jni_weak_index); }
+  static OopStorage* vm_weak()    { return storage(vm_weak_index); }
+
+  static OopStorage* string_table_weak() {
+    return storage(string_table_weak_index);
+  }
+
+  static OopStorage* resolved_method_table_weak() {
+    return storage(resolved_method_table_weak_index);
+  }
+};
+
+class OopStorageSet::Iterator {
+  friend class OopStorageSet;
+
+  enum Category { singular, strong, weak, all };
+
+  uint _index;
+  uint _limit;
+  DEBUG_ONLY(Category _category;)
+
+  Iterator(uint index, uint limit, Category category) :
+    _index(index), _limit(limit) DEBUG_ONLY(COMMA _category(category)) {}
+
+  void verify_nonsingular() const NOT_DEBUG_RETURN;
+  void verify_category_match(const Iterator& other) const NOT_DEBUG_RETURN;
+  void verify_dereferenceable() const NOT_DEBUG_RETURN;
+
+public:
+  // Construct a singular iterator for later assignment.  The only valid
+  // operations are destruction and assignment.
+  Iterator() :
+    _index(singular_index),
+    _limit(singular_index)
+    DEBUG_ONLY(COMMA _category(singular)) {}
+
+  bool is_end() const {
+    verify_nonsingular();
+    return _index == _limit;
+  }
+
+  bool operator==(const Iterator& other) const {
+    verify_category_match(other);
+    return _index == other._index;
+  }
+
+  bool operator!=(const Iterator& other) const {
+    return !operator==(other);
+  }
+
+  OopStorage* operator*() const {
+    verify_dereferenceable();
+    return storage(_index);
+  }
+
+  OopStorage* operator->() const {
+    return operator*();
+  }
+
+  Iterator& operator++() {
+    verify_dereferenceable();
+    ++_index;
+    return *this;
+  }
+
+  Iterator operator++(int) {
+    Iterator result = *this;
+    operator++();
+    return result;
+  }
+
+  Iterator begin() const {
+    verify_nonsingular();
+    return *this;
+  }
+
+  Iterator end() const {
+    verify_nonsingular();
+    Iterator result = *this;
+    result._index = _limit;
+    return result;
+  }
+};
+
+inline OopStorageSet::Iterator OopStorageSet::strong_iterator() {
+  return Iterator(strong_start, strong_end, Iterator::strong);
+}
+
+inline OopStorageSet::Iterator OopStorageSet::weak_iterator() {
+  return Iterator(weak_start, weak_end, Iterator::weak);
+}
+
+inline OopStorageSet::Iterator OopStorageSet::all_iterator() {
+  return Iterator(all_start, all_end, Iterator::all);
+}
+
+#endif // SHARE_GC_SHARED_OOPSTORAGESET_HPP