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src/share/vm/memory/referencePolicy.hpp@7b0e9cba0307 (annotated)

src/share/vm/memory/referencePolicy.hpp

Wed, 13 Jan 2010 15:26:39 -0800

author

ysr

date

Wed, 13 Jan 2010 15:26:39 -0800

changeset 1601

7b0e9cba0307

parent 905

ad8c8ca4ab0f

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6896647: card marks can be deferred too long
Summary: Deferred card marks are now flushed during the gc prologue. Parallel[Scavege,OldGC] and SerialGC no longer defer card marks generated by COMPILER2 as a result of ReduceInitialCardMarks. For these cases, introduced a diagnostic option to defer the card marks, only for the purposes of testing and diagnostics. CMS and G1 continue to defer card marks. Potential performance concern related to single-threaded flushing of deferred card marks in the gc prologue will be addressed in the future.
Reviewed-by: never, johnc

duke@435	1	/*
xdono@905	2	* Copyright 2000-2008 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	// referencePolicy is used to determine when soft reference objects
duke@435	26	// should be cleared.
duke@435	27
duke@435	28
ysr@888	29	class ReferencePolicy : public CHeapObj {
duke@435	30	public:
duke@435	31	virtual bool should_clear_reference(oop p) { ShouldNotReachHere(); return true; }
ysr@888	32	// Capture state (of-the-VM) information needed to evaluate the policy
ysr@892	33	virtual void setup() { /* do nothing */ }
duke@435	34	};
duke@435	35
duke@435	36	class NeverClearPolicy : public ReferencePolicy {
duke@435	37	public:
duke@435	38	bool should_clear_reference(oop p) { return false; }
duke@435	39	};
duke@435	40
duke@435	41	class AlwaysClearPolicy : public ReferencePolicy {
duke@435	42	public:
duke@435	43	bool should_clear_reference(oop p) { return true; }
duke@435	44	};
duke@435	45
duke@435	46	class LRUCurrentHeapPolicy : public ReferencePolicy {
duke@435	47	private:
duke@435	48	jlong _max_interval;
duke@435	49
duke@435	50	public:
duke@435	51	LRUCurrentHeapPolicy();
duke@435	52
ysr@888	53	// Capture state (of-the-VM) information needed to evaluate the policy
ysr@892	54	void setup();
duke@435	55	bool should_clear_reference(oop p);
duke@435	56	};
duke@435	57
duke@435	58	class LRUMaxHeapPolicy : public ReferencePolicy {
duke@435	59	private:
duke@435	60	jlong _max_interval;
duke@435	61
duke@435	62	public:
duke@435	63	LRUMaxHeapPolicy();
duke@435	64
ysr@888	65	// Capture state (of-the-VM) information needed to evaluate the policy
ysr@892	66	void setup();
duke@435	67	bool should_clear_reference(oop p);
duke@435	68	};