src/hotspot/share/memory/heap.hpp

rev 54943 : 8223444: Improve CodeHeap Free Space Management
Reviewed-by: kvn, thartmann

*** 49,58 ****
--- 49,60 ----
    };
  
   public:
    // Initialization
    void initialize(size_t length)                 { _header._length = length; set_used(); }
+   // Merging/splitting
+   void set_length(size_t length)                 { _header._length = length; }
  
    // Accessors
    void* allocated_space() const                  { return (void*)(this + 1); }
    size_t length() const                          { return _header._length; }
  
*** 69,81 ****
  
   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; }
  };
  
--- 71,80 ----
*** 113,141 ****
  
    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* 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
--- 112,143 ----
  
    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)); }
  
+   // These methods take segment map indices as range boundaries
    void mark_segmap_as_free(size_t beg, size_t end);
    void mark_segmap_as_used(size_t beg, size_t end);
+   void invalidate(size_t beg, size_t end, size_t header_bytes);
+   void clear(size_t beg, size_t end);
+   void clear();                                 // clears all heap contents
  
    // 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);
!   HeapBlock* search_freelist(size_t length);
  
    // Iteration helpers
    void*      next_used(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(const char* name, const int code_blob_type);
  
    // Heap extents
*** 178,187 ****
--- 180,190 ----
    static size_t header_size();                   // returns the header size for each heap block
  
    size_t segment_size()         const { return _segment_size; }  // for CodeHeapState
    HeapBlock* first_block() const;                                // for CodeHeapState
    HeapBlock* next_block(HeapBlock* b) const;                     // for CodeHeapState
+   HeapBlock* split_block(HeapBlock* b, size_t split_seg);        // split one block into two
  
    FreeBlock* freelist()         const { return _freelist; }      // for CodeHeapState
  
    size_t allocated_in_freelist() const           { return _freelist_segments * CodeCacheSegmentSize; }
    int    freelist_length()       const           { return _freelist_length; } // number of elements in the freelist