jdk8-mips64-public/hotspot: src/share/vm/memory/heap.hpp@8ce625481709 (annotated)

src/share/vm/memory/heap.hpp@8ce625481709 (annotated)

src/share/vm/memory/heap.hpp

Fri, 15 Apr 2011 09:36:28 -0400

author: coleenp
date: Fri, 15 Apr 2011 09:36:28 -0400
changeset 2777: 8ce625481709
parent 2414: 51bd2d261853
child 3900: d2a62e0f25eb
permissions: -rw-r--r--

7032407: Crash in LinkResolver::runtime_resolve_virtual_method()
Summary: Make CDS reorder vtables so that dump time vtables match run time order, so when redefine classes reinitializes them, they aren't in the wrong order.
Reviewed-by: dcubed, acorn

 /*
  * Copyright (c) 1997, 2010, 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.
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  */
 #ifndef SHARE_VM_MEMORY_HEAP_HPP
 #define SHARE_VM_MEMORY_HEAP_HPP
 #include "memory/allocation.hpp"
 #include "runtime/virtualspace.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 {
   friend class VMStructs;
  private:
   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       _free_segments;                   // No. of segments in freelist
   // Helper functions
   size_t   number_of_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; }
   size_t   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; }
   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);
   void merge_right (FreeBlock* a);
   // Toplevel freelist management
   void add_to_freelist(HeapBlock *b);
   FreeBlock* search_freelist(size_t length);
   // Iteration helpers
   void*      next_free(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);
  public:
   CodeHeap();
   // Heap extents
   bool  reserve(size_t reserved_size, size_t committed_size, size_t segment_size);
   void  release();                               // releases all allocated memory
   bool  expand_by(size_t size);                  // expands commited memory by size
   void  shrink_by(size_t size);                  // shrinks commited memory by size
   void  clear();                                 // clears all heap contents
   // Memory allocation
   void* allocate  (size_t size);                 // allocates a block of size or returns NULL
   void  deallocate(void* p);                     // deallocates a block
   // Attributes
   void*  begin() const                           { return _memory.low (); }
   void*  end() const                             { return _memory.high(); }
   bool   contains(void* p) const                 { return begin() <= p && p < end(); }
   void*  find_start(void* p) const;              // returns the block containing p or NULL
   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
   // Returns reserved area high and low addresses
   char *low_boundary() const                     { return _memory.low_boundary (); }
   char *high() const                             { return _memory.high(); }
   char *high_boundary() const                    { return _memory.high_boundary(); }
   // Iteration
   // returns the first block or NULL
   void* first() const       { return next_free(first_block()); }
   // returns the next block given a block p or NULL
   void* next(void* p) const { return next_free(next_block(block_start(p))); }
   // Statistics
   size_t capacity() const;
   size_t max_capacity() const;
   size_t allocated_capacity() const;
   size_t unallocated_capacity() const            { return max_capacity() - allocated_capacity(); }
   size_t largest_free_block() const;
   // Debugging
   void verify();
   void print()  PRODUCT_RETURN;
 };
 #endif // SHARE_VM_MEMORY_HEAP_HPP

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src/share/vm/memory/heap.hpp@8ce625481709 (annotated)

src/share/vm/memory/heap.hpp