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src/share/vm/memory/heap.hpp@ddce0b7cee93 (annotated)

src/share/vm/memory/heap.hpp

Tue, 24 Feb 2015 15:04:52 -0500

author

dlong

date

Tue, 24 Feb 2015 15:04:52 -0500

changeset 7598

ddce0b7cee93

parent 6198

55fb97c4c58d

child 6876

710a3c8b516e

permissions

-rw-r--r--

8072383: resolve conflicts between open and closed ports
Summary: refactor close to remove references to closed ports
Reviewed-by: kvn, simonis, sgehwolf, dholmes

duke@435	1	/*
mikael@6198	2	* Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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	*
trims@1907	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	20	* or visit www.oracle.com if you need additional information or have any
trims@1907	21	* questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
stefank@2314	25	#ifndef SHARE_VM_MEMORY_HEAP_HPP
stefank@2314	26	#define SHARE_VM_MEMORY_HEAP_HPP
stefank@2314	27
stefank@2314	28	#include "memory/allocation.hpp"
stefank@2314	29	#include "runtime/virtualspace.hpp"
stefank@2314	30
duke@435	31	// Blocks
duke@435	32
duke@435	33	class HeapBlock VALUE_OBJ_CLASS_SPEC {
duke@435	34	friend class VMStructs;
duke@435	35
duke@435	36	public:
duke@435	37	struct Header {
duke@435	38	size_t _length; // the length in segments
duke@435	39	bool _used; // Used bit
duke@435	40	};
duke@435	41
duke@435	42	protected:
duke@435	43	union {
duke@435	44	Header _header;
duke@435	45	int64_t _padding[ (sizeof(Header) + sizeof(int64_t)-1) / sizeof(int64_t) ];
duke@435	46	// pad to 0 mod 8
duke@435	47	};
duke@435	48
duke@435	49	public:
duke@435	50	// Initialization
duke@435	51	void initialize(size_t length) { _header._length = length; set_used(); }
duke@435	52
duke@435	53	// Accessors
duke@435	54	void* allocated_space() const { return (void*)(this + 1); }
duke@435	55	size_t length() const { return _header._length; }
duke@435	56
duke@435	57	// Used/free
duke@435	58	void set_used() { _header._used = true; }
duke@435	59	void set_free() { _header._used = false; }
duke@435	60	bool free() { return !_header._used; }
duke@435	61	};
duke@435	62
duke@435	63	class FreeBlock: public HeapBlock {
duke@435	64	friend class VMStructs;
duke@435	65	protected:
duke@435	66	FreeBlock* _link;
duke@435	67
duke@435	68	public:
duke@435	69	// Initialization
duke@435	70	void initialize(size_t length) { HeapBlock::initialize(length); _link= NULL; }
duke@435	71
duke@435	72	// Merging
duke@435	73	void set_length(size_t l) { _header._length = l; }
duke@435	74
duke@435	75	// Accessors
duke@435	76	FreeBlock* link() const { return _link; }
duke@435	77	void set_link(FreeBlock* link) { _link = link; }
duke@435	78	};
duke@435	79
zgu@3900	80	class CodeHeap : public CHeapObj<mtCode> {
duke@435	81	friend class VMStructs;
duke@435	82	private:
duke@435	83	VirtualSpace _memory; // the memory holding the blocks
duke@435	84	VirtualSpace _segmap; // the memory holding the segment map
duke@435	85
duke@435	86	size_t _number_of_committed_segments;
duke@435	87	size_t _number_of_reserved_segments;
duke@435	88	size_t _segment_size;
duke@435	89	int _log2_segment_size;
duke@435	90
duke@435	91	size_t _next_segment;
duke@435	92
duke@435	93	FreeBlock* _freelist;
neliasso@4952	94	size_t _freelist_segments; // No. of segments in freelist
duke@435	95
duke@435	96	// Helper functions
neliasso@4952	97	size_t size_to_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; }
neliasso@4952	98	size_t segments_to_size(size_t number_of_segments) const { return number_of_segments << _log2_segment_size; }
duke@435	99
duke@435	100	size_t segment_for(void* p) const { return ((char*)p - _memory.low()) >> _log2_segment_size; }
duke@435	101	HeapBlock* block_at(size_t i) const { return (HeapBlock*)(_memory.low() + (i << _log2_segment_size)); }
duke@435	102
duke@435	103	void mark_segmap_as_free(size_t beg, size_t end);
duke@435	104	void mark_segmap_as_used(size_t beg, size_t end);
duke@435	105
duke@435	106	// Freelist management helpers
duke@435	107	FreeBlock* following_block(FreeBlock *b);
duke@435	108	void insert_after(FreeBlock* a, FreeBlock* b);
duke@435	109	void merge_right (FreeBlock* a);
duke@435	110
duke@435	111	// Toplevel freelist management
duke@435	112	void add_to_freelist(HeapBlock *b);
neliasso@4952	113	FreeBlock* search_freelist(size_t length, bool is_critical);
duke@435	114
duke@435	115	// Iteration helpers
duke@435	116	void* next_free(HeapBlock* b) const;
duke@435	117	HeapBlock* first_block() const;
duke@435	118	HeapBlock* next_block(HeapBlock* b) const;
duke@435	119	HeapBlock* block_start(void* p) const;
duke@435	120
duke@435	121	// to perform additional actions on creation of executable code
duke@435	122	void on_code_mapping(char* base, size_t size);
duke@435	123
duke@435	124	public:
duke@435	125	CodeHeap();
duke@435	126
duke@435	127	// Heap extents
duke@435	128	bool reserve(size_t reserved_size, size_t committed_size, size_t segment_size);
duke@435	129	void release(); // releases all allocated memory
duke@435	130	bool expand_by(size_t size); // expands commited memory by size
duke@435	131	void shrink_by(size_t size); // shrinks commited memory by size
duke@435	132	void clear(); // clears all heap contents
duke@435	133
duke@435	134	// Memory allocation
neliasso@4952	135	void* allocate (size_t size, bool is_critical); // allocates a block of size or returns NULL
duke@435	136	void deallocate(void* p); // deallocates a block
duke@435	137
duke@435	138	// Attributes
neliasso@4952	139	char* low_boundary() const { return _memory.low_boundary (); }
neliasso@4952	140	char* high() const { return _memory.high(); }
neliasso@4952	141	char* high_boundary() const { return _memory.high_boundary(); }
duke@435	142
neliasso@4952	143	bool contains(const void* p) const { return low_boundary() <= p && p < high(); }
neliasso@4952	144	void* find_start(void* p) const; // returns the block containing p or NULL
neliasso@4952	145	size_t alignment_unit() const; // alignment of any block
neliasso@4952	146	size_t alignment_offset() const; // offset of first byte of any block, within the enclosing alignment unit
neliasso@4952	147	static size_t header_size(); // returns the header size for each heap block
duke@435	148
duke@435	149	// Iteration
duke@435	150
duke@435	151	// returns the first block or NULL
duke@435	152	void* first() const { return next_free(first_block()); }
duke@435	153	// returns the next block given a block p or NULL
duke@435	154	void* next(void* p) const { return next_free(next_block(block_start(p))); }
duke@435	155
duke@435	156	// Statistics
duke@435	157	size_t capacity() const;
duke@435	158	size_t max_capacity() const;
duke@435	159	size_t allocated_capacity() const;
duke@435	160	size_t unallocated_capacity() const { return max_capacity() - allocated_capacity(); }
duke@435	161
neliasso@4952	162	private:
neliasso@4952	163	size_t heap_unallocated_capacity() const;
neliasso@4952	164
neliasso@4952	165	public:
duke@435	166	// Debugging
duke@435	167	void verify();
duke@435	168	void print() PRODUCT_RETURN;
duke@435	169	};
stefank@2314	170
stefank@2314	171	#endif // SHARE_VM_MEMORY_HEAP_HPP