diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/memory/heap.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/heap.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,205 @@
+/*
+ * Copyright (c) 1997, 2015, 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_VM_MEMORY_HEAP_HPP
+#define SHARE_VM_MEMORY_HEAP_HPP
+
+#include "code/codeBlob.hpp"
+#include "memory/allocation.hpp"
+#include "memory/virtualspace.hpp"
+#include "utilities/macros.hpp"
+
+// Blocks
+
+class HeapBlock VALUE_OBJ_CLASS_SPEC {
+  friend class VMStructs;
+
+ public:
+  struct Header {
+    size_t  _length;                             // the length in segments
+    bool    _used;                               // Used bit
+  };
+
+ protected:
+  union {
+    Header _header;
+    int64_t _padding[ (sizeof(Header) + sizeof(int64_t)-1) / sizeof(int64_t) ];
+                        // pad to 0 mod 8
+  };
+
+ public:
+  // Initialization
+  void initialize(size_t length)                 { _header._length = length; set_used(); }
+
+  // Accessors
+  void* allocated_space() const                  { return (void*)(this + 1); }
+  size_t length() const                          { return _header._length; }
+
+  // Used/free
+  void set_used()                                { _header._used = true; }
+  void set_free()                                { _header._used = false; }
+  bool free()                                    { return !_header._used; }
+};
+
+class FreeBlock: public HeapBlock {
+  friend class VMStructs;
+ protected:
+  FreeBlock* _link;
+
+ public:
+  // Initialization
+  void initialize(size_t length)             { HeapBlock::initialize(length); _link= NULL; }
+
+  // Merging
+  void set_length(size_t l)                  { _header._length = l; }
+
+  // Accessors
+  FreeBlock* link() const                    { return _link; }
+  void set_link(FreeBlock* link)             { _link = link; }
+};
+
+class CodeHeap : public CHeapObj<mtCode> {
+  friend class VMStructs;
+ protected:
+  VirtualSpace _memory;                          // the memory holding the blocks
+  VirtualSpace _segmap;                          // the memory holding the segment map
+
+  size_t       _number_of_committed_segments;
+  size_t       _number_of_reserved_segments;
+  size_t       _segment_size;
+  int          _log2_segment_size;
+
+  size_t       _next_segment;
+
+  FreeBlock*   _freelist;
+  size_t       _freelist_segments;               // No. of segments in freelist
+  int          _freelist_length;
+  size_t       _max_allocated_capacity;          // Peak capacity that was allocated during lifetime of the heap
+
+  const char*  _name;                            // Name of the CodeHeap
+  const int    _code_blob_type;                  // CodeBlobType it contains
+  int          _blob_count;                      // Number of CodeBlobs
+  int          _nmethod_count;                   // Number of nmethods
+  int          _adapter_count;                   // Number of adapters
+  int          _full_count;                      // Number of times the code heap was full
+
+
+  enum { free_sentinel = 0xFF };
+
+  // Helper functions
+  size_t   size_to_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; }
+  size_t   segments_to_size(size_t number_of_segments) const { return number_of_segments << _log2_segment_size; }
+
+  size_t   segment_for(void* p) const            { return ((char*)p - _memory.low()) >> _log2_segment_size; }
+  bool     is_segment_unused(int val) const      { return val == free_sentinel; }
+  HeapBlock* block_at(size_t i) const            { return (HeapBlock*)(_memory.low() + (i << _log2_segment_size)); }
+
+  void  mark_segmap_as_free(size_t beg, size_t end);
+  void  mark_segmap_as_used(size_t beg, size_t end);
+
+  // Freelist management helpers
+  FreeBlock* following_block(FreeBlock* b);
+  void insert_after(FreeBlock* a, FreeBlock* b);
+  bool merge_right (FreeBlock* a);
+
+  // Toplevel freelist management
+  void add_to_freelist(HeapBlock* b);
+  FreeBlock* search_freelist(size_t length);
+
+  // Iteration helpers
+  void*      next_used(HeapBlock* b) const;
+  HeapBlock* first_block() const;
+  HeapBlock* next_block(HeapBlock* b) const;
+  HeapBlock* block_start(void* p) const;
+
+  // to perform additional actions on creation of executable code
+  void on_code_mapping(char* base, size_t size);
+  void clear();                                 // clears all heap contents
+
+ public:
+  CodeHeap(const char* name, const int code_blob_type);
+
+  // Heap extents
+  bool  reserve(ReservedSpace rs, size_t committed_size, size_t segment_size);
+  bool  expand_by(size_t size);                  // expands committed memory by size
+
+  // Memory allocation
+  void* allocate (size_t size); // Allocate 'size' bytes in the code cache or return NULL
+  void  deallocate(void* p);    // Deallocate memory
+
+  // Attributes
+  char* low_boundary() const                     { return _memory.low_boundary(); }
+  char* high() const                             { return _memory.high(); }
+  char* high_boundary() const                    { return _memory.high_boundary(); }
+
+  bool contains(const void* p) const             { return low_boundary() <= p && p < high(); }
+  bool contains_blob(const CodeBlob* blob) const { return contains(blob->code_begin()); }
+
+  virtual void* find_start(void* p)     const;   // returns the block containing p or NULL
+  virtual CodeBlob* find_blob_unsafe(void* start) const;
+  size_t alignment_unit()       const;           // alignment of any block
+  size_t alignment_offset()     const;           // offset of first byte of any block, within the enclosing alignment unit
+  static size_t header_size();                   // returns the header size for each heap block
+
+  size_t allocated_in_freelist() const           { return _freelist_segments * CodeCacheSegmentSize; }
+  int    freelist_length()       const           { return _freelist_length; } // number of elements in the freelist
+
+  // returns the first block or NULL
+  virtual void* first() const                    { return next_used(first_block()); }
+  // returns the next block given a block p or NULL
+  virtual void* next(void* p) const              { return next_used(next_block(block_start(p))); }
+
+  // Statistics
+  size_t capacity() const;
+  size_t max_capacity() const;
+  int    allocated_segments() const;
+  size_t allocated_capacity() const;
+  size_t max_allocated_capacity() const          { return _max_allocated_capacity; }
+  size_t unallocated_capacity() const            { return max_capacity() - allocated_capacity(); }
+
+  // Returns true if the CodeHeap contains CodeBlobs of the given type
+  bool accepts(int code_blob_type) const         { return (_code_blob_type == CodeBlobType::All) ||
+                                                          (_code_blob_type == code_blob_type); }
+  int code_blob_type() const                     { return _code_blob_type; }
+
+  // Debugging / Profiling
+  const char* name() const                       { return _name; }
+  int         blob_count()                       { return _blob_count; }
+  int         nmethod_count()                    { return _nmethod_count; }
+  void    set_nmethod_count(int count)           {        _nmethod_count = count; }
+  int         adapter_count()                    { return _adapter_count; }
+  void    set_adapter_count(int count)           {        _adapter_count = count; }
+  int         full_count()                       { return _full_count; }
+  void        report_full()                      {        _full_count++; }
+
+private:
+  size_t heap_unallocated_capacity() const;
+
+public:
+  // Debugging
+  void verify() PRODUCT_RETURN;
+  void print()  PRODUCT_RETURN;
+};
+
+#endif // SHARE_VM_MEMORY_HEAP_HPP