duke@435: /*
mikael@6198:  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #ifndef SHARE_VM_MEMORY_HEAP_HPP
stefank@2314: #define SHARE_VM_MEMORY_HEAP_HPP
stefank@2314: 
stefank@2314: #include "memory/allocation.hpp"
stefank@2314: #include "runtime/virtualspace.hpp"
stefank@2314: 
duke@435: // Blocks
duke@435: 
duke@435: class HeapBlock VALUE_OBJ_CLASS_SPEC {
duke@435:   friend class VMStructs;
duke@435: 
duke@435:  public:
duke@435:   struct Header {
duke@435:     size_t  _length;                             // the length in segments
duke@435:     bool    _used;                               // Used bit
duke@435:   };
duke@435: 
duke@435:  protected:
duke@435:   union {
duke@435:     Header _header;
duke@435:     int64_t _padding[ (sizeof(Header) + sizeof(int64_t)-1) / sizeof(int64_t) ];
duke@435:                         // pad to 0 mod 8
duke@435:   };
duke@435: 
duke@435:  public:
duke@435:   // Initialization
duke@435:   void initialize(size_t length)                 { _header._length = length; set_used(); }
duke@435: 
duke@435:   // Accessors
duke@435:   void* allocated_space() const                  { return (void*)(this + 1); }
duke@435:   size_t length() const                          { return _header._length; }
duke@435: 
duke@435:   // Used/free
duke@435:   void set_used()                                { _header._used = true; }
duke@435:   void set_free()                                { _header._used = false; }
duke@435:   bool free()                                    { return !_header._used; }
duke@435: };
duke@435: 
duke@435: class FreeBlock: public HeapBlock {
duke@435:   friend class VMStructs;
duke@435:  protected:
duke@435:   FreeBlock* _link;
duke@435: 
duke@435:  public:
duke@435:   // Initialization
duke@435:   void initialize(size_t length)             { HeapBlock::initialize(length); _link= NULL; }
duke@435: 
duke@435:   // Merging
duke@435:   void set_length(size_t l)                  { _header._length = l; }
duke@435: 
duke@435:   // Accessors
duke@435:   FreeBlock* link() const                    { return _link; }
duke@435:   void set_link(FreeBlock* link)             { _link = link; }
duke@435: };
duke@435: 
zgu@3900: class CodeHeap : public CHeapObj<mtCode> {
duke@435:   friend class VMStructs;
duke@435:  private:
duke@435:   VirtualSpace _memory;                          // the memory holding the blocks
duke@435:   VirtualSpace _segmap;                          // the memory holding the segment map
duke@435: 
duke@435:   size_t       _number_of_committed_segments;
duke@435:   size_t       _number_of_reserved_segments;
duke@435:   size_t       _segment_size;
duke@435:   int          _log2_segment_size;
duke@435: 
duke@435:   size_t       _next_segment;
duke@435: 
duke@435:   FreeBlock*   _freelist;
neliasso@4952:   size_t       _freelist_segments;               // No. of segments in freelist
duke@435: 
duke@435:   // Helper functions
neliasso@4952:   size_t   size_to_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; }
neliasso@4952:   size_t   segments_to_size(size_t number_of_segments) const { return number_of_segments << _log2_segment_size; }
duke@435: 
duke@435:   size_t   segment_for(void* p) const            { return ((char*)p - _memory.low()) >> _log2_segment_size; }
duke@435:   HeapBlock* block_at(size_t i) const            { return (HeapBlock*)(_memory.low() + (i << _log2_segment_size)); }
duke@435: 
duke@435:   void  mark_segmap_as_free(size_t beg, size_t end);
duke@435:   void  mark_segmap_as_used(size_t beg, size_t end);
duke@435: 
duke@435:   // Freelist management helpers
duke@435:   FreeBlock* following_block(FreeBlock *b);
duke@435:   void insert_after(FreeBlock* a, FreeBlock* b);
duke@435:   void merge_right (FreeBlock* a);
duke@435: 
duke@435:   // Toplevel freelist management
duke@435:   void add_to_freelist(HeapBlock *b);
neliasso@4952:   FreeBlock* search_freelist(size_t length, bool is_critical);
duke@435: 
duke@435:   // Iteration helpers
duke@435:   void*      next_free(HeapBlock* b) const;
duke@435:   HeapBlock* first_block() const;
duke@435:   HeapBlock* next_block(HeapBlock* b) const;
duke@435:   HeapBlock* block_start(void* p) const;
duke@435: 
duke@435:   // to perform additional actions on creation of executable code
duke@435:   void on_code_mapping(char* base, size_t size);
duke@435: 
duke@435:  public:
duke@435:   CodeHeap();
duke@435: 
duke@435:   // Heap extents
duke@435:   bool  reserve(size_t reserved_size, size_t committed_size, size_t segment_size);
duke@435:   void  release();                               // releases all allocated memory
duke@435:   bool  expand_by(size_t size);                  // expands commited memory by size
duke@435:   void  shrink_by(size_t size);                  // shrinks commited memory by size
duke@435:   void  clear();                                 // clears all heap contents
duke@435: 
duke@435:   // Memory allocation
neliasso@4952:   void* allocate  (size_t size, bool is_critical);  // allocates a block of size or returns NULL
duke@435:   void  deallocate(void* p);                     // deallocates a block
duke@435: 
duke@435:   // Attributes
neliasso@4952:   char* low_boundary() const                     { return _memory.low_boundary (); }
neliasso@4952:   char* high() const                             { return _memory.high(); }
neliasso@4952:   char* high_boundary() const                    { return _memory.high_boundary(); }
duke@435: 
neliasso@4952:   bool  contains(const void* p) const            { return low_boundary() <= p && p < high(); }
neliasso@4952:   void* find_start(void* p) const;              // returns the block containing p or NULL
neliasso@4952:   size_t alignment_unit() const;                // alignment of any block
neliasso@4952:   size_t alignment_offset() const;              // offset of first byte of any block, within the enclosing alignment unit
neliasso@4952:   static size_t header_size();                  // returns the header size for each heap block
duke@435: 
duke@435:   // Iteration
duke@435: 
duke@435:   // returns the first block or NULL
duke@435:   void* first() const       { return next_free(first_block()); }
duke@435:   // returns the next block given a block p or NULL
duke@435:   void* next(void* p) const { return next_free(next_block(block_start(p))); }
duke@435: 
duke@435:   // Statistics
duke@435:   size_t capacity() const;
duke@435:   size_t max_capacity() const;
duke@435:   size_t allocated_capacity() const;
duke@435:   size_t unallocated_capacity() const            { return max_capacity() - allocated_capacity(); }
duke@435: 
neliasso@4952: private:
neliasso@4952:   size_t heap_unallocated_capacity() const;
neliasso@4952: 
neliasso@4952: public:
duke@435:   // Debugging
duke@435:   void verify();
duke@435:   void print()  PRODUCT_RETURN;
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_MEMORY_HEAP_HPP