• file
• revisions
• annotate
• diff
• comparison
• raw

src/share/vm/memory/modRefBarrierSet.hpp@37f87013dfd8 (annotated)

src/share/vm/memory/modRefBarrierSet.hpp

Thu, 05 Jun 2008 15:57:56 -0700

author

ysr

date

Thu, 05 Jun 2008 15:57:56 -0700

changeset 777

37f87013dfd8

parent 548

ba764ed4b6f2

child 791

1ee8caae33af

permissions

-rw-r--r--

6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr

duke@435	1	/*
duke@435	2	* Copyright 2000-2002 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	// This kind of "BarrierSet" allows a "CollectedHeap" to detect and
duke@435	26	// enumerate ref fields that have been modified (since the last
duke@435	27	// enumeration), using a card table.
duke@435	28
duke@435	29	class OopClosure;
duke@435	30	class Generation;
duke@435	31
duke@435	32	class ModRefBarrierSet: public BarrierSet {
duke@435	33	public:
ysr@777	34
ysr@777	35	ModRefBarrierSet() { _kind = BarrierSet::ModRef; }
ysr@777	36
ysr@777	37	bool is_a(BarrierSet::Name bsn) {
ysr@777	38	return bsn == BarrierSet::ModRef;
ysr@777	39	}
ysr@777	40
duke@435	41	// Barriers only on ref writes.
duke@435	42	bool has_read_ref_barrier() { return false; }
duke@435	43	bool has_read_prim_barrier() { return false; }
duke@435	44	bool has_write_ref_barrier() { return true; }
duke@435	45	bool has_write_prim_barrier() { return false; }
duke@435	46
coleenp@548	47	bool read_ref_needs_barrier(void* field) { return false; }
duke@435	48	bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
coleenp@548	49	virtual bool write_ref_needs_barrier(void* field, oop new_val) = 0;
duke@435	50	bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
duke@435	51	juint val1, juint val2) { return false; }
duke@435	52
duke@435	53	void write_prim_field(oop obj, size_t offset, size_t bytes,
duke@435	54	juint val1, juint val2) {}
duke@435	55
coleenp@548	56	void read_ref_field(void* field) {}
duke@435	57	void read_prim_field(HeapWord* field, size_t bytes) {}
duke@435	58	protected:
coleenp@548	59	virtual void write_ref_field_work(void* field, oop new_val) = 0;
duke@435	60	public:
duke@435	61	void write_prim_field(HeapWord* field, size_t bytes,
duke@435	62	juint val1, juint val2) {}
duke@435	63
duke@435	64	bool has_read_ref_array_opt() { return false; }
duke@435	65	bool has_read_prim_array_opt() { return false; }
duke@435	66	bool has_write_prim_array_opt() { return false; }
duke@435	67
duke@435	68	bool has_read_region_opt() { return false; }
duke@435	69
duke@435	70
duke@435	71	// These operations should assert false unless the correponding operation
duke@435	72	// above returns true.
duke@435	73	void read_ref_array(MemRegion mr) {
duke@435	74	assert(false, "can't call");
duke@435	75	}
duke@435	76	void read_prim_array(MemRegion mr) {
duke@435	77	assert(false, "can't call");
duke@435	78	}
duke@435	79	void write_prim_array(MemRegion mr) {
duke@435	80	assert(false, "can't call");
duke@435	81	}
duke@435	82	void read_region(MemRegion mr) {
duke@435	83	assert(false, "can't call");
duke@435	84	}
duke@435	85
duke@435	86	// Invoke "cl->do_oop" on (the address of) every possibly-modifed
duke@435	87	// reference field in objects in "sp". If "clear" is "true", the oops
duke@435	88	// are no longer considered possibly modified after application of the
duke@435	89	// closure. If' "before_save_marks" is true, oops in objects allocated
duke@435	90	// after the last call to "save_marks" on "sp" will not be considered.
duke@435	91	virtual void mod_oop_in_space_iterate(Space* sp, OopClosure* cl,
duke@435	92	bool clear = false,
duke@435	93	bool before_save_marks = false) = 0;
duke@435	94
ysr@777	95	// Causes all refs in "mr" to be assumed to be modified. If "whole_heap"
ysr@777	96	// is true, the caller asserts that the entire heap is being invalidated,
ysr@777	97	// which may admit an optimized implementation for some barriers.
ysr@777	98	virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0;
duke@435	99
duke@435	100	// The caller guarantees that "mr" contains no references. (Perhaps it's
duke@435	101	// objects have been moved elsewhere.)
duke@435	102	virtual void clear(MemRegion mr) = 0;
duke@435	103
duke@435	104	// Pass along the argument to the superclass.
duke@435	105	ModRefBarrierSet(int max_covered_regions) :
duke@435	106	BarrierSet(max_covered_regions) {}
duke@435	107
duke@435	108	#ifndef PRODUCT
duke@435	109	// Verifies that the given region contains no modified references.
duke@435	110	virtual void verify_clean_region(MemRegion mr) = 0;
duke@435	111	#endif
duke@435	112
duke@435	113	};