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src/share/vm/classfile/metadataOnStackMark.cpp@0b9ea9a72436 (annotated)

src/share/vm/classfile/metadataOnStackMark.cpp

Mon, 18 Nov 2013 10:20:13 +0100

author

sla

date

Mon, 18 Nov 2013 10:20:13 +0100

changeset 6122

0b9ea9a72436

parent 6063

910026b800b8

child 6876

710a3c8b516e

child 6992

2c6ef90f030a

permissions

-rw-r--r--

8027630: SIGSEGV in const char*Klass::external_name()
Reviewed-by: coleenp, sspitsyn, mgronlun

coleenp@4490	1	/*
coleenp@4490	2	* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
coleenp@4490	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
coleenp@4490	4	*
coleenp@4490	5	* This code is free software; you can redistribute it and/or modify it
coleenp@4490	6	* under the terms of the GNU General Public License version 2 only, as
coleenp@4490	7	* published by the Free Software Foundation.
coleenp@4490	8	*
coleenp@4490	9	* This code is distributed in the hope that it will be useful, but WITHOUT
coleenp@4490	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
coleenp@4490	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
coleenp@4490	12	* version 2 for more details (a copy is included in the LICENSE file that
coleenp@4490	13	* accompanied this code).
coleenp@4490	14	*
coleenp@4490	15	* You should have received a copy of the GNU General Public License version
coleenp@4490	16	* 2 along with this work; if not, write to the Free Software Foundation,
coleenp@4490	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
coleenp@4490	18	*
coleenp@4490	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
coleenp@4490	20	* or visit www.oracle.com if you need additional information or have any
coleenp@4490	21	* questions.
coleenp@4490	22	*
coleenp@4490	23	*/
coleenp@4490	24
coleenp@4490	25	#include "precompiled.hpp"
coleenp@4490	26	#include "classfile/metadataOnStackMark.hpp"
coleenp@4490	27	#include "code/codeCache.hpp"
coleenp@4490	28	#include "compiler/compileBroker.hpp"
coleenp@4490	29	#include "oops/metadata.hpp"
coleenp@6063	30	#include "prims/jvmtiImpl.hpp"
coleenp@4490	31	#include "runtime/synchronizer.hpp"
coleenp@4490	32	#include "runtime/thread.hpp"
sla@6122	33	#include "services/threadService.hpp"
coleenp@4490	34	#include "utilities/growableArray.hpp"
coleenp@4490	35
coleenp@4490	36
coleenp@4490	37	// Keep track of marked on-stack metadata so it can be cleared.
coleenp@4490	38	GrowableArray<Metadata*>* _marked_objects = NULL;
coleenp@4490	39	NOT_PRODUCT(bool MetadataOnStackMark::_is_active = false;)
coleenp@4490	40
coleenp@4490	41	// Walk metadata on the stack and mark it so that redefinition doesn't delete
coleenp@4490	42	// it. Class unloading also walks the previous versions and might try to
coleenp@4490	43	// delete it, so this class is used by class unloading also.
coleenp@4490	44	MetadataOnStackMark::MetadataOnStackMark() {
coleenp@4490	45	assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
coleenp@4490	46	NOT_PRODUCT(_is_active = true;)
coleenp@4490	47	if (_marked_objects == NULL) {
coleenp@4490	48	_marked_objects = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(1000, true);
coleenp@4490	49	}
coleenp@4490	50	Threads::metadata_do(Metadata::mark_on_stack);
coleenp@4490	51	CodeCache::alive_nmethods_do(nmethod::mark_on_stack);
coleenp@4490	52	CompileBroker::mark_on_stack();
coleenp@6063	53	JvmtiCurrentBreakpoints::metadata_do(Metadata::mark_on_stack);
sla@6122	54	ThreadService::metadata_do(Metadata::mark_on_stack);
coleenp@4490	55	}
coleenp@4490	56
coleenp@4490	57	MetadataOnStackMark::~MetadataOnStackMark() {
coleenp@4490	58	assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
coleenp@4490	59	// Unmark everything that was marked. Can't do the same walk because
coleenp@4490	60	// redefine classes messes up the code cache so the set of methods
coleenp@4490	61	// might not be the same.
coleenp@4490	62	for (int i = 0; i< _marked_objects->length(); i++) {
coleenp@4490	63	_marked_objects->at(i)->set_on_stack(false);
coleenp@4490	64	}
coleenp@4490	65	_marked_objects->clear(); // reuse growable array for next time.
coleenp@4490	66	NOT_PRODUCT(_is_active = false;)
coleenp@4490	67	}
coleenp@4490	68
coleenp@4490	69	// Record which objects are marked so we can unmark the same objects.
coleenp@4490	70	void MetadataOnStackMark::record(Metadata* m) {
coleenp@4490	71	assert(_is_active, "metadata on stack marking is active");
coleenp@4490	72	_marked_objects->push(m);
coleenp@4490	73	}