--- a/src/hotspot/share/memory/metaspace/virtualSpaceList.hpp	Fri Apr 05 09:18:18 2019 +0200
+++ b/src/hotspot/share/memory/metaspace/virtualSpaceList.hpp	Wed Mar 27 14:13:34 2019 +0100
@@ -58,6 +58,19 @@
   // Number of virtual spaces
   size_t _virtual_space_count;
 
+  // Optimization: we keep an address range to quickly exclude pointers
+  // which are clearly not pointing into metaspace. This is an optimization for
+  // VirtualSpaceList::contains().
+  address _envelope_lo;
+  address _envelope_hi;
+
+  bool is_within_envelope(address p) const {
+    return p >= _envelope_lo && p < _envelope_hi;
+  }
+
+  // Given a node, expand range such that it includes the node.
+  void expand_envelope_to_include_node(const VirtualSpaceNode* node);
+
   ~VirtualSpaceList();
 
   VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; }
@@ -80,6 +93,8 @@
   // virtual space and add the chunks to the free list.
   void retire_current_virtual_space();
 
+  DEBUG_ONLY(bool contains_node(const VirtualSpaceNode* node) const;)
+
  public:
   VirtualSpaceList(size_t word_size);
   VirtualSpaceList(ReservedSpace rs);
@@ -126,6 +141,8 @@
   void print_on(outputStream* st, size_t scale) const;
   void print_map(outputStream* st) const;
 
+  DEBUG_ONLY(void verify(bool slow);)
+
   class VirtualSpaceListIterator : public StackObj {
     VirtualSpaceNode* _virtual_spaces;
    public: