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