/*

 * Copyright (c) 2014, 2018, 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 "aot/aotLoader.hpp"

#include "classfile/stringTable.hpp"

#include "classfile/systemDictionary.hpp"

#include "gc/shared/strongRootsScope.hpp"

#include "jfr/leakprofiler/chains/edgeQueue.hpp"

#include "jfr/leakprofiler/chains/rootSetClosure.hpp"

#include "jfr/leakprofiler/utilities/saveRestore.hpp"

#include "jfr/leakprofiler/utilities/unifiedOop.hpp"

#include "memory/universe.hpp"

#include "oops/access.inline.hpp"

#include "prims/jvmtiExport.hpp"

#include "runtime/jniHandles.inline.hpp"

#include "runtime/synchronizer.hpp"

#include "runtime/thread.hpp"

#include "services/management.hpp"

#include "utilities/align.hpp"

RootSetClosure::RootSetClosure(EdgeQueue* edge_queue) :

  _edge_queue(edge_queue) {

}

void RootSetClosure::do_oop(oop* ref) {

  assert(ref != NULL, "invariant");

  // We discard unaligned root references because

  // our reference tagging scheme will use

  // the lowest bit in a represented reference

  // to indicate the reference is narrow.

  // It is mainly roots delivered via nmethods::do_oops()

  // that come in unaligned. It should be ok to duck these

  // since they are supposedly weak.

  if (!is_aligned(ref, HeapWordSize)) {

    return;

  }

  assert(is_aligned(ref, HeapWordSize), "invariant");

  const oop pointee = *ref;

  if (pointee != NULL) {

    closure_impl(ref, pointee);

  }

}

void RootSetClosure::do_oop(narrowOop* ref) {

  assert(ref != NULL, "invariant");

  assert(is_aligned(ref, sizeof(narrowOop)), "invariant");

  const oop pointee = RawAccess<>::oop_load(ref);

  if (pointee != NULL) {

    closure_impl(UnifiedOop::encode(ref), pointee);

  }

}

void RootSetClosure::closure_impl(const oop* reference, const oop pointee) {

  if (!_edge_queue->is_full())  {

    _edge_queue->add(NULL, reference);

  }

}

void RootSetClosure::add_to_queue(EdgeQueue* edge_queue) {

  RootSetClosure rs(edge_queue);

  process_roots(&rs);

}

class RootSetClosureMarkScope : public MarkScope {

};

void RootSetClosure::process_roots(OopClosure* closure) {

  SaveRestoreCLDClaimBits save_restore_cld_claim_bits;

  RootSetClosureMarkScope mark_scope;

  CLDToOopClosure cldt_closure(closure);

  ClassLoaderDataGraph::always_strong_cld_do(&cldt_closure);

  CodeBlobToOopClosure blobs(closure, false);

  Threads::oops_do(closure, &blobs);

  ObjectSynchronizer::oops_do(closure);

  Universe::oops_do(closure);

  JNIHandles::oops_do(closure);

  JvmtiExport::oops_do(closure);

  SystemDictionary::oops_do(closure);

  Management::oops_do(closure);

  StringTable::oops_do(closure);

  AOTLoader::oops_do(closure);

}