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src/share/vm/memory/genRemSet.hpp@981375ca07b7 (annotated)

src/share/vm/memory/genRemSet.hpp

Fri, 17 Apr 2009 12:22:18 -0700

author

never

date

Fri, 17 Apr 2009 12:22:18 -0700

changeset 1149

981375ca07b7

parent 791

1ee8caae33af

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6831604: missing null check in guarantee
Reviewed-by: kvn

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 GenRemSet provides ways of iterating over pointers accross generations.
duke@435	26	// (This is especially useful for older-to-younger.)
duke@435	27
duke@435	28	class Generation;
duke@435	29	class BarrierSet;
duke@435	30	class OopsInGenClosure;
duke@435	31	class CardTableRS;
duke@435	32
duke@435	33	class GenRemSet: public CHeapObj {
duke@435	34	friend class Generation;
duke@435	35
duke@435	36	BarrierSet* _bs;
duke@435	37
duke@435	38	public:
duke@435	39	enum Name {
duke@435	40	CardTable,
duke@435	41	Other
duke@435	42	};
duke@435	43
duke@435	44	GenRemSet(BarrierSet * bs) : _bs(bs) {}
ysr@777	45	GenRemSet() : _bs(NULL) {}
duke@435	46
duke@435	47	virtual Name rs_kind() = 0;
duke@435	48
duke@435	49	// These are for dynamic downcasts. Unfortunately that it names the
duke@435	50	// possible subtypes (but not that they are subtypes!) Return NULL if
duke@435	51	// the cast is invalide.
duke@435	52	virtual CardTableRS* as_CardTableRS() { return NULL; }
duke@435	53
duke@435	54	// Return the barrier set associated with "this."
duke@435	55	BarrierSet* bs() { return _bs; }
duke@435	56
ysr@777	57	// Set the barrier set.
ysr@777	58	void set_bs(BarrierSet* bs) { _bs = bs; }
ysr@777	59
duke@435	60	// Do any (sequential) processing necessary to prepare for (possibly
duke@435	61	// "parallel", if that arg is true) calls to younger_refs_iterate.
duke@435	62	virtual void prepare_for_younger_refs_iterate(bool parallel) = 0;
duke@435	63
duke@435	64	// Apply the "do_oop" method of "blk" to (exactly) all oop locations
duke@435	65	// 1) that are in objects allocated in "g" at the time of the last call
duke@435	66	// to "save_Marks", and
duke@435	67	// 2) that point to objects in younger generations.
duke@435	68	virtual void younger_refs_iterate(Generation* g, OopsInGenClosure* blk) = 0;
duke@435	69
duke@435	70	virtual void younger_refs_in_space_iterate(Space* sp,
duke@435	71	OopsInGenClosure* cl) = 0;
duke@435	72
duke@435	73	// This method is used to notify the remembered set that "new_val" has
duke@435	74	// been written into "field" by the garbage collector.
coleenp@548	75	void write_ref_field_gc(void* field, oop new_val);
duke@435	76	protected:
coleenp@548	77	virtual void write_ref_field_gc_work(void* field, oop new_val) = 0;
duke@435	78	public:
duke@435	79
duke@435	80	// A version of the above suitable for use by parallel collectors.
coleenp@548	81	virtual void write_ref_field_gc_par(void* field, oop new_val) = 0;
duke@435	82
duke@435	83	// Resize one of the regions covered by the remembered set.
duke@435	84	virtual void resize_covered_region(MemRegion new_region) = 0;
duke@435	85
duke@435	86	// If the rem set imposes any alignment restrictions on boundaries
duke@435	87	// within the heap, this function tells whether they are met.
duke@435	88	virtual bool is_aligned(HeapWord* addr) = 0;
duke@435	89
duke@435	90	// If the RS (or BS) imposes an aligment constraint on maximum heap size.
duke@435	91	// (This must be static, and dispatch on "nm", because it is called
duke@435	92	// before an RS is created.)
duke@435	93	static uintx max_alignment_constraint(Name nm);
duke@435	94
duke@435	95	virtual void verify() = 0;
duke@435	96
duke@435	97	// Verify that the remembered set has no entries for
jmasa@441	98	// the heap interval denoted by mr. If there are any
jmasa@441	99	// alignment constraints on the remembered set, only the
jmasa@441	100	// part of the region that is aligned is checked.
jmasa@441	101	//
jmasa@441	102	// alignment boundaries
jmasa@441	103	// +--------+-------+--------+-------+
jmasa@441	104	// [ region mr )
jmasa@441	105	// [ part checked )
jmasa@441	106	virtual void verify_aligned_region_empty(MemRegion mr) = 0;
duke@435	107
duke@435	108	// If appropriate, print some information about the remset on "tty".
duke@435	109	virtual void print() {}
duke@435	110
duke@435	111	// Informs the RS that the given memregion contains no references to
duke@435	112	// younger generations.
duke@435	113	virtual void clear(MemRegion mr) = 0;
duke@435	114
duke@435	115	// Informs the RS that there are no references to generations
duke@435	116	// younger than gen from generations gen and older.
duke@435	117	// The parameter clear_perm indicates if the perm_gen's
duke@435	118	// remembered set should also be processed/cleared.
duke@435	119	virtual void clear_into_younger(Generation* gen, bool clear_perm) = 0;
duke@435	120
duke@435	121	// Informs the RS that refs in the given "mr" may have changed
duke@435	122	// arbitrarily, and therefore may contain old-to-young pointers.
ysr@777	123	// If "whole heap" is true, then this invalidation is part of an
ysr@777	124	// invalidation of the whole heap, which an implementation might
ysr@777	125	// handle differently than that of a sub-part of the heap.
ysr@777	126	virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0;
duke@435	127
duke@435	128	// Informs the RS that refs in this generation
duke@435	129	// may have changed arbitrarily, and therefore may contain
duke@435	130	// old-to-young pointers in arbitrary locations. The parameter
duke@435	131	// younger indicates if the same should be done for younger generations
duke@435	132	// as well. The parameter perm indicates if the same should be done for
duke@435	133	// perm gen as well.
duke@435	134	virtual void invalidate_or_clear(Generation* gen, bool younger, bool perm) = 0;
duke@435	135	};