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src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.hpp@c96030fff130 (annotated)

src/share/vm/gc_implementation/concurrentMarkSweep/freeBlockDictionary.hpp

Thu, 20 Nov 2008 16:56:09 -0800

author

ysr

date

Thu, 20 Nov 2008 16:56:09 -0800

changeset 888

c96030fff130

parent 704

850fdf70db2b

child 1580

e018e6884bd8

permissions

-rw-r--r--

6684579: SoftReference processing can be made more efficient
Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa

duke@435	1	/*
xdono@631	2	* Copyright 2001-2008 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	// A FreeBlockDictionary is an abstract superclass that will allow
duke@435	26	// a number of alternative implementations in the future.
duke@435	27	class FreeBlockDictionary: public CHeapObj {
duke@435	28	public:
duke@435	29	enum Dither {
duke@435	30	atLeast,
duke@435	31	exactly,
duke@435	32	roughly
duke@435	33	};
duke@435	34	enum DictionaryChoice {
duke@435	35	dictionaryBinaryTree = 0,
duke@435	36	dictionarySplayTree = 1,
duke@435	37	dictionarySkipList = 2
duke@435	38	};
duke@435	39
duke@435	40	private:
duke@435	41	NOT_PRODUCT(Mutex* _lock;)
duke@435	42
duke@435	43	public:
duke@435	44	virtual void removeChunk(FreeChunk* fc) = 0;
duke@435	45	virtual FreeChunk* getChunk(size_t size, Dither dither = atLeast) = 0;
duke@435	46	virtual void returnChunk(FreeChunk* chunk) = 0;
duke@435	47	virtual size_t totalChunkSize(debug_only(const Mutex* lock)) const = 0;
duke@435	48	virtual size_t maxChunkSize() const = 0;
duke@435	49	virtual size_t minSize() const = 0;
duke@435	50	// Reset the dictionary to the initial conditions for a single
duke@435	51	// block.
duke@435	52	virtual void reset(HeapWord* addr, size_t size) = 0;
duke@435	53	virtual void reset() = 0;
duke@435	54
duke@435	55	virtual void dictCensusUpdate(size_t size, bool split, bool birth) = 0;
duke@435	56	virtual bool coalDictOverPopulated(size_t size) = 0;
duke@435	57	virtual void beginSweepDictCensus(double coalSurplusPercent,
duke@435	58	float sweep_current, float sweep_ewstimate) = 0;
duke@435	59	virtual void endSweepDictCensus(double splitSurplusPercent) = 0;
duke@435	60	virtual FreeChunk* findLargestDict() const = 0;
duke@435	61	// verify that the given chunk is in the dictionary.
duke@435	62	virtual bool verifyChunkInFreeLists(FreeChunk* tc) const = 0;
duke@435	63
duke@435	64	// Sigma_{all_free_blocks} (block_size^2)
duke@435	65	virtual double sum_of_squared_block_sizes() const = 0;
duke@435	66
duke@435	67	virtual FreeChunk* find_chunk_ends_at(HeapWord* target) const = 0;
duke@435	68	virtual void inc_totalSize(size_t v) = 0;
duke@435	69	virtual void dec_totalSize(size_t v) = 0;
duke@435	70
duke@435	71	NOT_PRODUCT (
duke@435	72	virtual size_t sumDictReturnedBytes() = 0;
duke@435	73	virtual void initializeDictReturnedBytes() = 0;
duke@435	74	virtual size_t totalCount() = 0;
duke@435	75	)
duke@435	76
duke@435	77	virtual void reportStatistics() const {
duke@435	78	gclog_or_tty->print("No statistics available");
duke@435	79	}
duke@435	80
duke@435	81	virtual void printDictCensus() const = 0;
duke@435	82
duke@435	83	virtual void verify() const = 0;
duke@435	84
duke@435	85	Mutex* par_lock() const PRODUCT_RETURN0;
duke@435	86	void set_par_lock(Mutex* lock) PRODUCT_RETURN;
duke@435	87	void verify_par_locked() const PRODUCT_RETURN;
duke@435	88	};