coleenp@4490: /*
coleenp@4490:  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
coleenp@4490:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
coleenp@4490:  *
coleenp@4490:  * This code is free software; you can redistribute it and/or modify it
coleenp@4490:  * under the terms of the GNU General Public License version 2 only, as
coleenp@4490:  * published by the Free Software Foundation.
coleenp@4490:  *
coleenp@4490:  * This code is distributed in the hope that it will be useful, but WITHOUT
coleenp@4490:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
coleenp@4490:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
coleenp@4490:  * version 2 for more details (a copy is included in the LICENSE file that
coleenp@4490:  * accompanied this code).
coleenp@4490:  *
coleenp@4490:  * You should have received a copy of the GNU General Public License version
coleenp@4490:  * 2 along with this work; if not, write to the Free Software Foundation,
coleenp@4490:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
coleenp@4490:  *
coleenp@4490:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
coleenp@4490:  * or visit www.oracle.com if you need additional information or have any
coleenp@4490:  * questions.
coleenp@4490:  *
coleenp@4490:  */
coleenp@4490: 
coleenp@4490: #include "precompiled.hpp"
coleenp@4490: #include "classfile/metadataOnStackMark.hpp"
coleenp@4490: #include "code/codeCache.hpp"
coleenp@4490: #include "compiler/compileBroker.hpp"
coleenp@4490: #include "oops/metadata.hpp"
coleenp@6063: #include "prims/jvmtiImpl.hpp"
coleenp@4490: #include "runtime/synchronizer.hpp"
coleenp@4490: #include "runtime/thread.hpp"
sla@6122: #include "services/threadService.hpp"
coleenp@4490: #include "utilities/growableArray.hpp"
coleenp@4490: 
coleenp@4490: 
coleenp@4490: // Keep track of marked on-stack metadata so it can be cleared.
coleenp@4490: GrowableArray<Metadata*>* _marked_objects = NULL;
coleenp@4490: NOT_PRODUCT(bool MetadataOnStackMark::_is_active = false;)
coleenp@4490: 
coleenp@4490: // Walk metadata on the stack and mark it so that redefinition doesn't delete
coleenp@4490: // it.  Class unloading also walks the previous versions and might try to
coleenp@4490: // delete it, so this class is used by class unloading also.
coleenp@4490: MetadataOnStackMark::MetadataOnStackMark() {
coleenp@4490:   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
coleenp@4490:   NOT_PRODUCT(_is_active = true;)
coleenp@4490:   if (_marked_objects == NULL) {
coleenp@4490:     _marked_objects = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(1000, true);
coleenp@4490:   }
stefank@6992: 
coleenp@4490:   Threads::metadata_do(Metadata::mark_on_stack);
stefank@6992:   if (JvmtiExport::has_redefined_a_class()) {
stefank@6992:     CodeCache::alive_nmethods_do(nmethod::mark_on_stack);
stefank@6992:   }
coleenp@4490:   CompileBroker::mark_on_stack();
coleenp@6063:   JvmtiCurrentBreakpoints::metadata_do(Metadata::mark_on_stack);
sla@6122:   ThreadService::metadata_do(Metadata::mark_on_stack);
coleenp@4490: }
coleenp@4490: 
coleenp@4490: MetadataOnStackMark::~MetadataOnStackMark() {
coleenp@4490:   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
coleenp@4490:   // Unmark everything that was marked.   Can't do the same walk because
coleenp@4490:   // redefine classes messes up the code cache so the set of methods
coleenp@4490:   // might not be the same.
coleenp@4490:   for (int i = 0; i< _marked_objects->length(); i++) {
coleenp@4490:     _marked_objects->at(i)->set_on_stack(false);
coleenp@4490:   }
coleenp@4490:   _marked_objects->clear();   // reuse growable array for next time.
coleenp@4490:   NOT_PRODUCT(_is_active = false;)
coleenp@4490: }
coleenp@4490: 
coleenp@4490: // Record which objects are marked so we can unmark the same objects.
coleenp@4490: void MetadataOnStackMark::record(Metadata* m) {
coleenp@4490:   assert(_is_active, "metadata on stack marking is active");
coleenp@4490:   _marked_objects->push(m);
coleenp@4490: }