jdk-24/hotspot/src/share/vm/memory/genRemSet.cpp
Jon Masamitsu 5c58d27aac 6964458: Reimplement class meta-data storage to use native memory
Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes

Co-authored-by: Stefan Karlsson <stefan.karlsson@oracle.com>
Co-authored-by: Mikael Gerdin <mikael.gerdin@oracle.com>
Co-authored-by: Tom Rodriguez <tom.rodriguez@oracle.com>
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
2012-09-01 13:25:18 -04:00

83 lines
2.4 KiB
C++

/*
* Copyright (c) 2001, 2012, 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/classLoaderData.hpp"
#include "memory/cardTableRS.hpp"
#include "memory/genRemSet.hpp"
// This kind of "BarrierSet" allows a "CollectedHeap" to detect and
// enumerate ref fields that have been modified (since the last
// enumeration.)
uintx GenRemSet::max_alignment_constraint(Name nm) {
switch (nm) {
case GenRemSet::CardTable:
return CardTableRS::ct_max_alignment_constraint();
default:
guarantee(false, "Unrecognized GenRemSet type.");
return (0); // Make Windows compiler happy
}
}
class HasAccumulatedModifiedOopsClosure : public KlassClosure {
bool _found;
public:
HasAccumulatedModifiedOopsClosure() : _found(false) {}
void do_klass(Klass* klass) {
if (_found) {
return;
}
if (klass->has_accumulated_modified_oops()) {
_found = true;
}
}
bool found() {
return _found;
}
};
bool KlassRemSet::mod_union_is_clear() {
HasAccumulatedModifiedOopsClosure closure;
ClassLoaderDataGraph::classes_do(&closure);
return !closure.found();
}
class ClearKlassModUnionClosure : public KlassClosure {
public:
void do_klass(Klass* klass) {
if (klass->has_accumulated_modified_oops()) {
klass->clear_accumulated_modified_oops();
}
}
};
void KlassRemSet::clear_mod_union() {
ClearKlassModUnionClosure closure;
ClassLoaderDataGraph::classes_do(&closure);
}