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src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.hpp@4dfb2df418f2 (annotated)

src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.hpp

Thu, 22 Sep 2011 10:57:37 -0700

author

johnc

date

Thu, 22 Sep 2011 10:57:37 -0700

changeset 3175

4dfb2df418f2

parent 2314

f95d63e2154a

child 3294

bca17e38de00

permissions

-rw-r--r--

6484982: G1: process references during evacuation pauses
Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate.
Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp

duke@435	1	/*
jmasa@1967	2	* Copyright (c) 2001, 2010, 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_GC_IMPLEMENTATION_PARALLELSCAVENGE_CARDTABLEEXTENSION_HPP
stefank@2314	26	#define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_CARDTABLEEXTENSION_HPP
stefank@2314	27
stefank@2314	28	#include "memory/cardTableModRefBS.hpp"
stefank@2314	29
duke@435	30	class MutableSpace;
duke@435	31	class ObjectStartArray;
duke@435	32	class PSPromotionManager;
duke@435	33	class GCTaskQueue;
duke@435	34
duke@435	35	class CardTableExtension : public CardTableModRefBS {
duke@435	36	private:
duke@435	37	// Support methods for resizing the card table.
jmasa@1967	38	// resize_commit_uncommit() returns true if the pages were committed or
jmasa@1967	39	// uncommitted
jmasa@1967	40	bool resize_commit_uncommit(int changed_region, MemRegion new_region);
duke@435	41	void resize_update_card_table_entries(int changed_region,
duke@435	42	MemRegion new_region);
duke@435	43	void resize_update_committed_table(int changed_region, MemRegion new_region);
duke@435	44	void resize_update_covered_table(int changed_region, MemRegion new_region);
duke@435	45
duke@435	46	protected:
duke@435	47
duke@435	48	static void verify_all_young_refs_precise_helper(MemRegion mr);
duke@435	49
duke@435	50	public:
duke@435	51	enum ExtendedCardValue {
duke@435	52	youngergen_card = CardTableModRefBS::CT_MR_BS_last_reserved + 1,
duke@435	53	verify_card = CardTableModRefBS::CT_MR_BS_last_reserved + 5
duke@435	54	};
duke@435	55
duke@435	56	CardTableExtension(MemRegion whole_heap, int max_covered_regions) :
duke@435	57	CardTableModRefBS(whole_heap, max_covered_regions) { }
duke@435	58
duke@435	59	// Too risky for the 4/10/02 putback
duke@435	60	// BarrierSet::Name kind() { return BarrierSet::CardTableExtension; }
duke@435	61
duke@435	62	// Scavenge support
duke@435	63	void scavenge_contents(ObjectStartArray* start_array,
duke@435	64	MutableSpace* sp,
duke@435	65	HeapWord* space_top,
duke@435	66	PSPromotionManager* pm);
duke@435	67
duke@435	68	void scavenge_contents_parallel(ObjectStartArray* start_array,
duke@435	69	MutableSpace* sp,
duke@435	70	HeapWord* space_top,
duke@435	71	PSPromotionManager* pm,
duke@435	72	uint stripe_number);
duke@435	73
duke@435	74	// Verification
duke@435	75	static void verify_all_young_refs_imprecise();
duke@435	76	static void verify_all_young_refs_precise();
duke@435	77
duke@435	78	bool addr_is_marked_imprecise(void *addr);
duke@435	79	bool addr_is_marked_precise(void *addr);
duke@435	80
duke@435	81	void set_card_newgen(void* addr) { jbyte* p = byte_for(addr); *p = verify_card; }
duke@435	82
duke@435	83	// Testers for entries
duke@435	84	static bool card_is_dirty(int value) { return value == dirty_card; }
duke@435	85	static bool card_is_newgen(int value) { return value == youngergen_card; }
duke@435	86	static bool card_is_clean(int value) { return value == clean_card; }
duke@435	87	static bool card_is_verify(int value) { return value == verify_card; }
duke@435	88
duke@435	89	// Card marking
coleenp@548	90	void inline_write_ref_field_gc(void* field, oop new_val) {
duke@435	91	jbyte* byte = byte_for(field);
duke@435	92	*byte = youngergen_card;
duke@435	93	}
duke@435	94
duke@435	95	// Adaptive size policy support
duke@435	96	// Allows adjustment of the base and size of the covered regions
duke@435	97	void resize_covered_region(MemRegion new_region);
duke@435	98	// Finds the covered region to resize based on the start address
duke@435	99	// of the covered regions.
duke@435	100	void resize_covered_region_by_start(MemRegion new_region);
duke@435	101	// Finds the covered region to resize based on the end address
duke@435	102	// of the covered regions.
duke@435	103	void resize_covered_region_by_end(int changed_region, MemRegion new_region);
duke@435	104	// Finds the lowest start address of a covered region that is
duke@435	105	// previous (i.e., lower index) to the covered region with index "ind".
duke@435	106	HeapWord* lowest_prev_committed_start(int ind) const;
duke@435	107
duke@435	108	#ifdef ASSERT
duke@435	109
duke@435	110	bool is_valid_card_address(jbyte* addr) {
duke@435	111	return (addr >= _byte_map) && (addr < _byte_map + _byte_map_size);
duke@435	112	}
duke@435	113
duke@435	114	#endif // ASSERT
duke@435	115	};
stefank@2314	116
stefank@2314	117	#endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_CARDTABLEEXTENSION_HPP