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src/share/vm/oops/instanceMirrorKlass.hpp@e1162778c1c8 (annotated)

src/share/vm/oops/instanceMirrorKlass.hpp

Thu, 07 Apr 2011 09:53:20 -0700

author

johnc

date

Thu, 07 Apr 2011 09:53:20 -0700

changeset 2781

e1162778c1c8

parent 2658

c7f3d0b4570f

child 2693

63997f575155

permissions

-rw-r--r--

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error
Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes

never@2658	1	/*
never@2658	2	* Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
never@2658	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
never@2658	4	*
never@2658	5	* This code is free software; you can redistribute it and/or modify it
never@2658	6	* under the terms of the GNU General Public License version 2 only, as
never@2658	7	* published by the Free Software Foundation.
never@2658	8	*
never@2658	9	* This code is distributed in the hope that it will be useful, but WITHOUT
never@2658	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
never@2658	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
never@2658	12	* version 2 for more details (a copy is included in the LICENSE file that
never@2658	13	* accompanied this code).
never@2658	14	*
never@2658	15	* You should have received a copy of the GNU General Public License version
never@2658	16	* 2 along with this work; if not, write to the Free Software Foundation,
never@2658	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
never@2658	18	*
never@2658	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
never@2658	20	* or visit www.oracle.com if you need additional information or have any
never@2658	21	* questions.
never@2658	22	*
never@2658	23	*/
never@2658	24
never@2658	25	#ifndef SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP
never@2658	26	#define SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP
never@2658	27
never@2658	28	#include "oops/instanceKlass.hpp"
never@2658	29
never@2658	30	// An instanceMirrorKlass is a specialized instanceKlass for
never@2658	31	// java.lang.Class instances. These instances are special because
never@2658	32	// they contain the static fields of the class in addition to the
never@2658	33	// normal fields of Class. This means they are variable sized
never@2658	34	// instances and need special logic for computing their size and for
never@2658	35	// iteration of their oops.
never@2658	36
never@2658	37
never@2658	38	class instanceMirrorKlass: public instanceKlass {
never@2658	39	private:
never@2658	40	static int _offset_of_static_fields;
never@2658	41
never@2658	42	public:
never@2658	43	// Type testing
never@2658	44	bool oop_is_instanceMirror() const { return true; }
never@2658	45
never@2658	46	// Casting from klassOop
never@2658	47	static instanceMirrorKlass* cast(klassOop k) {
never@2658	48	assert(k->klass_part()->oop_is_instanceMirror(), "cast to instanceMirrorKlass");
never@2658	49	return (instanceMirrorKlass*) k->klass_part();
never@2658	50	}
never@2658	51
never@2658	52	// Returns the size of the instance including the extra static fields.
never@2658	53	virtual int oop_size(oop obj) const;
never@2658	54
never@2658	55	// Static field offset is an offset into the Heap, should be converted by
never@2658	56	// based on UseCompressedOop for traversal
never@2658	57	static HeapWord* start_of_static_fields(oop obj) {
never@2658	58	return (HeapWord*)((intptr_t)obj + offset_of_static_fields());
never@2658	59	}
never@2658	60
never@2658	61	static void init_offset_of_static_fields() {
never@2658	62	// Cache the offset of the static fields in the Class instance
never@2658	63	assert(_offset_of_static_fields == 0, "once");
never@2658	64	_offset_of_static_fields = instanceMirrorKlass::cast(SystemDictionary::Class_klass())->size_helper() << LogHeapWordSize;
never@2658	65	}
never@2658	66
never@2658	67	static int offset_of_static_fields() {
never@2658	68	return _offset_of_static_fields;
never@2658	69	}
never@2658	70
never@2658	71	int compute_static_oop_field_count(oop obj);
never@2658	72
never@2658	73	// Given a Klass return the size of the instance
never@2658	74	int instance_size(KlassHandle k);
never@2658	75
never@2658	76	// allocation
never@2658	77	DEFINE_ALLOCATE_PERMANENT(instanceMirrorKlass);
never@2658	78	instanceOop allocate_instance(KlassHandle k, TRAPS);
never@2658	79
never@2658	80	// Garbage collection
never@2658	81	int oop_adjust_pointers(oop obj);
never@2658	82	void oop_follow_contents(oop obj);
never@2658	83
never@2658	84	// Parallel Scavenge and Parallel Old
never@2658	85	PARALLEL_GC_DECLS
never@2658	86
never@2658	87	int oop_oop_iterate(oop obj, OopClosure* blk) {
never@2658	88	return oop_oop_iterate_v(obj, blk);
never@2658	89	}
never@2658	90	int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
never@2658	91	return oop_oop_iterate_v_m(obj, blk, mr);
never@2658	92	}
never@2658	93
never@2658	94	#define InstanceMirrorKlass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \
never@2658	95	int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk); \
never@2658	96	int oop_oop_iterate##nv_suffix##_m(oop obj, OopClosureType* blk, MemRegion mr);
never@2658	97
never@2658	98	ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL)
never@2658	99	ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_DECL)
never@2658	100
never@2658	101	#ifndef SERIALGC
never@2658	102	#define InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \
never@2658	103	int oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* blk);
never@2658	104
never@2658	105	ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
never@2658	106	ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceMirrorKlass_OOP_OOP_ITERATE_BACKWARDS_DECL)
never@2658	107	#endif // !SERIALGC
never@2658	108	};
never@2658	109
never@2658	110	#endif // SHARE_VM_OOPS_INSTANCEMIRRORKLASS_HPP