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8006040: NPG: on_stack processing wastes space in ConstantPool

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Added on_stack bit to flags.  Also MetadataMarkOnStack is used for more than JVMTI so had to be moved.

Reviewed-by: dholmes, stefank
This commit is contained in:
Coleen Phillimore 2013-01-23 10:34:29 -05:00
parent 4d81507a36
commit 99039568f9
9 changed files with 152 additions and 96 deletions
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69
hotspot/src/share/vm/classfile/metadataOnStackMark.cpp Normal file
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/*
* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "classfile/metadataOnStackMark.hpp"
#include "code/codeCache.hpp"
#include "compiler/compileBroker.hpp"
#include "oops/metadata.hpp"
#include "runtime/synchronizer.hpp"
#include "runtime/thread.hpp"
#include "utilities/growableArray.hpp"
// Keep track of marked on-stack metadata so it can be cleared.
GrowableArray<Metadata*>* _marked_objects = NULL;
NOT_PRODUCT(bool MetadataOnStackMark::_is_active = false;)
// Walk metadata on the stack and mark it so that redefinition doesn't delete
// it. Class unloading also walks the previous versions and might try to
// delete it, so this class is used by class unloading also.
MetadataOnStackMark::MetadataOnStackMark() {
assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
NOT_PRODUCT(_is_active = true;)
if (_marked_objects == NULL) {
_marked_objects = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(1000, true);
}
Threads::metadata_do(Metadata::mark_on_stack);
CodeCache::alive_nmethods_do(nmethod::mark_on_stack);
CompileBroker::mark_on_stack();
}
MetadataOnStackMark::~MetadataOnStackMark() {
assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
// Unmark everything that was marked. Can't do the same walk because
// redefine classes messes up the code cache so the set of methods
// might not be the same.
for (int i = 0; i< _marked_objects->length(); i++) {
_marked_objects->at(i)->set_on_stack(false);
}
_marked_objects->clear(); // reuse growable array for next time.
NOT_PRODUCT(_is_active = false;)
}
// Record which objects are marked so we can unmark the same objects.
void MetadataOnStackMark::record(Metadata* m) {
assert(_is_active, "metadata on stack marking is active");
_marked_objects->push(m);
}