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src/share/vm/memory/modRefBarrierSet.hpp@749b1464aa81 (annotated)

src/share/vm/memory/modRefBarrierSet.hpp

Sun, 01 Apr 2012 17:04:26 -0400

author

acorn

date

Sun, 01 Apr 2012 17:04:26 -0400

changeset 3686

749b1464aa81

parent 2849

063382f9b575

child 4037

da91efe96a93

permissions

-rw-r--r--

Merge

duke@435	1	/*
ysr@2788	2	* Copyright (c) 2000, 2011, 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_MEMORY_MODREFBARRIERSET_HPP
stefank@2314	26	#define SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
stefank@2314	27
stefank@2314	28	#include "memory/barrierSet.hpp"
stefank@2314	29
duke@435	30	// This kind of "BarrierSet" allows a "CollectedHeap" to detect and
duke@435	31	// enumerate ref fields that have been modified (since the last
duke@435	32	// enumeration), using a card table.
duke@435	33
duke@435	34	class OopClosure;
duke@435	35	class Generation;
duke@435	36
duke@435	37	class ModRefBarrierSet: public BarrierSet {
duke@435	38	public:
ysr@777	39
ysr@777	40	ModRefBarrierSet() { _kind = BarrierSet::ModRef; }
ysr@777	41
ysr@777	42	bool is_a(BarrierSet::Name bsn) {
ysr@777	43	return bsn == BarrierSet::ModRef;
ysr@777	44	}
ysr@777	45
duke@435	46	// Barriers only on ref writes.
duke@435	47	bool has_read_ref_barrier() { return false; }
duke@435	48	bool has_read_prim_barrier() { return false; }
duke@435	49	bool has_write_ref_barrier() { return true; }
duke@435	50	bool has_write_prim_barrier() { return false; }
duke@435	51
coleenp@548	52	bool read_ref_needs_barrier(void* field) { return false; }
duke@435	53	bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
coleenp@548	54	virtual bool write_ref_needs_barrier(void* field, oop new_val) = 0;
duke@435	55	bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
duke@435	56	juint val1, juint val2) { return false; }
duke@435	57
duke@435	58	void write_prim_field(oop obj, size_t offset, size_t bytes,
duke@435	59	juint val1, juint val2) {}
duke@435	60
coleenp@548	61	void read_ref_field(void* field) {}
duke@435	62	void read_prim_field(HeapWord* field, size_t bytes) {}
duke@435	63	protected:
coleenp@548	64	virtual void write_ref_field_work(void* field, oop new_val) = 0;
duke@435	65	public:
duke@435	66	void write_prim_field(HeapWord* field, size_t bytes,
duke@435	67	juint val1, juint val2) {}
duke@435	68
duke@435	69	bool has_read_ref_array_opt() { return false; }
duke@435	70	bool has_read_prim_array_opt() { return false; }
duke@435	71	bool has_write_prim_array_opt() { return false; }
duke@435	72
duke@435	73	bool has_read_region_opt() { return false; }
duke@435	74
duke@435	75
duke@435	76	// These operations should assert false unless the correponding operation
duke@435	77	// above returns true.
duke@435	78	void read_ref_array(MemRegion mr) {
duke@435	79	assert(false, "can't call");
duke@435	80	}
duke@435	81	void read_prim_array(MemRegion mr) {
duke@435	82	assert(false, "can't call");
duke@435	83	}
duke@435	84	void write_prim_array(MemRegion mr) {
duke@435	85	assert(false, "can't call");
duke@435	86	}
duke@435	87	void read_region(MemRegion mr) {
duke@435	88	assert(false, "can't call");
duke@435	89	}
duke@435	90
ysr@777	91	// Causes all refs in "mr" to be assumed to be modified. If "whole_heap"
ysr@777	92	// is true, the caller asserts that the entire heap is being invalidated,
ysr@777	93	// which may admit an optimized implementation for some barriers.
ysr@777	94	virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0;
duke@435	95
duke@435	96	// The caller guarantees that "mr" contains no references. (Perhaps it's
duke@435	97	// objects have been moved elsewhere.)
duke@435	98	virtual void clear(MemRegion mr) = 0;
duke@435	99
duke@435	100	// Pass along the argument to the superclass.
duke@435	101	ModRefBarrierSet(int max_covered_regions) :
duke@435	102	BarrierSet(max_covered_regions) {}
duke@435	103	};
stefank@2314	104
stefank@2314	105	#endif // SHARE_VM_MEMORY_MODREFBARRIERSET_HPP