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src/share/vm/memory/heap.hpp@167c2986d91b (annotated)

src/share/vm/memory/heap.hpp

Wed, 16 Dec 2009 12:54:49 -0500

author

phh

date

Wed, 16 Dec 2009 12:54:49 -0500

changeset 1558

167c2986d91b

parent 435

a61af66fc99e

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6843629: Make current hotspot build part of jdk5 control build
Summary: Source changes for older compilers plus makefile changes.
Reviewed-by: xlu

duke@435	1	/*
duke@435	2	* Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	// Blocks
duke@435	26
duke@435	27	class HeapBlock VALUE_OBJ_CLASS_SPEC {
duke@435	28	friend class VMStructs;
duke@435	29
duke@435	30	public:
duke@435	31	struct Header {
duke@435	32	size_t _length; // the length in segments
duke@435	33	bool _used; // Used bit
duke@435	34	};
duke@435	35
duke@435	36	protected:
duke@435	37	union {
duke@435	38	Header _header;
duke@435	39	int64_t _padding[ (sizeof(Header) + sizeof(int64_t)-1) / sizeof(int64_t) ];
duke@435	40	// pad to 0 mod 8
duke@435	41	};
duke@435	42
duke@435	43	public:
duke@435	44	// Initialization
duke@435	45	void initialize(size_t length) { _header._length = length; set_used(); }
duke@435	46
duke@435	47	// Accessors
duke@435	48	void* allocated_space() const { return (void*)(this + 1); }
duke@435	49	size_t length() const { return _header._length; }
duke@435	50
duke@435	51	// Used/free
duke@435	52	void set_used() { _header._used = true; }
duke@435	53	void set_free() { _header._used = false; }
duke@435	54	bool free() { return !_header._used; }
duke@435	55	};
duke@435	56
duke@435	57	class FreeBlock: public HeapBlock {
duke@435	58	friend class VMStructs;
duke@435	59	protected:
duke@435	60	FreeBlock* _link;
duke@435	61
duke@435	62	public:
duke@435	63	// Initialization
duke@435	64	void initialize(size_t length) { HeapBlock::initialize(length); _link= NULL; }
duke@435	65
duke@435	66	// Merging
duke@435	67	void set_length(size_t l) { _header._length = l; }
duke@435	68
duke@435	69	// Accessors
duke@435	70	FreeBlock* link() const { return _link; }
duke@435	71	void set_link(FreeBlock* link) { _link = link; }
duke@435	72	};
duke@435	73
duke@435	74	class CodeHeap : public CHeapObj {
duke@435	75	friend class VMStructs;
duke@435	76	private:
duke@435	77	VirtualSpace _memory; // the memory holding the blocks
duke@435	78	VirtualSpace _segmap; // the memory holding the segment map
duke@435	79
duke@435	80	size_t _number_of_committed_segments;
duke@435	81	size_t _number_of_reserved_segments;
duke@435	82	size_t _segment_size;
duke@435	83	int _log2_segment_size;
duke@435	84
duke@435	85	size_t _next_segment;
duke@435	86
duke@435	87	FreeBlock* _freelist;
duke@435	88	size_t _free_segments; // No. of segments in freelist
duke@435	89
duke@435	90	// Helper functions
duke@435	91	size_t number_of_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; }
duke@435	92	size_t size(size_t number_of_segments) const { return number_of_segments << _log2_segment_size; }
duke@435	93
duke@435	94	size_t segment_for(void* p) const { return ((char*)p - _memory.low()) >> _log2_segment_size; }
duke@435	95	HeapBlock* block_at(size_t i) const { return (HeapBlock*)(_memory.low() + (i << _log2_segment_size)); }
duke@435	96
duke@435	97	void mark_segmap_as_free(size_t beg, size_t end);
duke@435	98	void mark_segmap_as_used(size_t beg, size_t end);
duke@435	99
duke@435	100	// Freelist management helpers
duke@435	101	FreeBlock* following_block(FreeBlock *b);
duke@435	102	void insert_after(FreeBlock* a, FreeBlock* b);
duke@435	103	void merge_right (FreeBlock* a);
duke@435	104
duke@435	105	// Toplevel freelist management
duke@435	106	void add_to_freelist(HeapBlock *b);
duke@435	107	FreeBlock* search_freelist(size_t length);
duke@435	108
duke@435	109	// Iteration helpers
duke@435	110	void* next_free(HeapBlock* b) const;
duke@435	111	HeapBlock* first_block() const;
duke@435	112	HeapBlock* next_block(HeapBlock* b) const;
duke@435	113	HeapBlock* block_start(void* p) const;
duke@435	114
duke@435	115	// to perform additional actions on creation of executable code
duke@435	116	void on_code_mapping(char* base, size_t size);
duke@435	117
duke@435	118	public:
duke@435	119	CodeHeap();
duke@435	120
duke@435	121	// Heap extents
duke@435	122	bool reserve(size_t reserved_size, size_t committed_size, size_t segment_size);
duke@435	123	void release(); // releases all allocated memory
duke@435	124	bool expand_by(size_t size); // expands commited memory by size
duke@435	125	void shrink_by(size_t size); // shrinks commited memory by size
duke@435	126	void clear(); // clears all heap contents
duke@435	127
duke@435	128	// Memory allocation
duke@435	129	void* allocate (size_t size); // allocates a block of size or returns NULL
duke@435	130	void deallocate(void* p); // deallocates a block
duke@435	131
duke@435	132	// Attributes
duke@435	133	void* begin() const { return _memory.low (); }
duke@435	134	void* end() const { return _memory.high(); }
duke@435	135	bool contains(void* p) const { return begin() <= p && p < end(); }
duke@435	136	void* find_start(void* p) const; // returns the block containing p or NULL
duke@435	137	size_t alignment_unit() const; // alignment of any block
duke@435	138	size_t alignment_offset() const; // offset of first byte of any block, within the enclosing alignment unit
duke@435	139	static size_t header_size(); // returns the header size for each heap block
duke@435	140
duke@435	141	// Returns reserved area high and low addresses
duke@435	142	char *low_boundary() const { return _memory.low_boundary (); }
duke@435	143	char *high_boundary() const { return _memory.high_boundary(); }
duke@435	144
duke@435	145	// Iteration
duke@435	146
duke@435	147	// returns the first block or NULL
duke@435	148	void* first() const { return next_free(first_block()); }
duke@435	149	// returns the next block given a block p or NULL
duke@435	150	void* next(void* p) const { return next_free(next_block(block_start(p))); }
duke@435	151
duke@435	152	// Statistics
duke@435	153	size_t capacity() const;
duke@435	154	size_t max_capacity() const;
duke@435	155	size_t allocated_capacity() const;
duke@435	156	size_t unallocated_capacity() const { return max_capacity() - allocated_capacity(); }
duke@435	157
duke@435	158	// Debugging
duke@435	159	void verify();
duke@435	160	void print() PRODUCT_RETURN;
duke@435	161	};