diff -r fd16c54261b3 -r 489c9b5090e2 hotspot/src/share/vm/memory/heap.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/src/share/vm/memory/heap.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,161 @@ +/* + * Copyright 1997-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +// 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_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(); } + + // Debugging + void verify(); + void print() PRODUCT_RETURN; +};