duke@435: /*
coleenp@4037:  * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #include "precompiled.hpp"
coleenp@4037: #include "classfile/classLoaderData.hpp"
stefank@2314: #include "memory/cardTableRS.hpp"
stefank@2314: #include "memory/genRemSet.hpp"
stefank@2314: 
duke@435: // This kind of "BarrierSet" allows a "CollectedHeap" to detect and
duke@435: // enumerate ref fields that have been modified (since the last
duke@435: // enumeration.)
duke@435: 
duke@435: uintx GenRemSet::max_alignment_constraint(Name nm) {
duke@435:   switch (nm) {
duke@435:   case GenRemSet::CardTable:
duke@435:     return CardTableRS::ct_max_alignment_constraint();
duke@435:   default:
duke@435:     guarantee(false, "Unrecognized GenRemSet type.");
duke@435:     return (0); // Make Windows compiler happy
duke@435:   }
duke@435: }
coleenp@4037: 
coleenp@4037: class HasAccumulatedModifiedOopsClosure : public KlassClosure {
coleenp@4037:   bool _found;
coleenp@4037:  public:
coleenp@4037:   HasAccumulatedModifiedOopsClosure() : _found(false) {}
coleenp@4037:   void do_klass(Klass* klass) {
coleenp@4037:     if (_found) {
coleenp@4037:       return;
coleenp@4037:     }
coleenp@4037: 
coleenp@4037:     if (klass->has_accumulated_modified_oops()) {
coleenp@4037:       _found = true;
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037:   bool found() {
coleenp@4037:     return _found;
coleenp@4037:   }
coleenp@4037: };
coleenp@4037: 
coleenp@4037: bool KlassRemSet::mod_union_is_clear() {
coleenp@4037:   HasAccumulatedModifiedOopsClosure closure;
coleenp@4037:   ClassLoaderDataGraph::classes_do(&closure);
coleenp@4037: 
coleenp@4037:   return !closure.found();
coleenp@4037: }
coleenp@4037: 
coleenp@4037: 
coleenp@4037: class ClearKlassModUnionClosure : public KlassClosure {
coleenp@4037:  public:
coleenp@4037:   void do_klass(Klass* klass) {
coleenp@4037:     if (klass->has_accumulated_modified_oops()) {
coleenp@4037:       klass->clear_accumulated_modified_oops();
coleenp@4037:     }
coleenp@4037:   }
coleenp@4037: };
coleenp@4037: 
coleenp@4037: void KlassRemSet::clear_mod_union() {
coleenp@4037:   ClearKlassModUnionClosure closure;
coleenp@4037:   ClassLoaderDataGraph::classes_do(&closure);
coleenp@4037: }