/*

 * Copyright (c) 2017, 2019, 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.

 *

 */

#ifndef SHARE_JFR_LEAKPROFILER_UTILITIES_SAVERESTORE_HPP

#define SHARE_JFR_LEAKPROFILER_UTILITIES_SAVERESTORE_HPP

#include "memory/allocation.hpp"

#include "memory/iterator.hpp"

#include "oops/markWord.hpp"

#include "utilities/growableArray.hpp"

template <typename T, typename Impl>

class SaveRestore {

 private:

  Impl _impl;

 public:

  SaveRestore() : _impl() {

    _impl.setup();

  }

  void save(T const& value) {

    _impl.save(value);

  }

  ~SaveRestore() {

    _impl.restore();

  }

};

template <typename T, typename Context>

class ContextStore {

private:

  GrowableArray<Context>* _storage;

public:

  ContextStore() : _storage(NULL) {}

  void setup() {

    assert(_storage == NULL, "invariant");

    _storage = new GrowableArray<Context>(16);

  }

  void save(T const& value) {

    _storage->push(Context(value));

  }

  void restore() {

    for (int i = 0; i < _storage->length(); ++i) {

      _storage->at(i).~Context();

    }

  }

};

/*

* This class will save the original mark oop of an object sample object.

* It will then install an "identifier" mark oop to be used for

* identification purposes in the search for reference chains.

* The destructor will restore the original mark oop.

*/

class MarkWordContext {

 private:

  oop _obj;

  markWord _mark_word;

  void swap(MarkWordContext& rhs);

 public:

  MarkWordContext();

  MarkWordContext(const oop obj);

  MarkWordContext(const MarkWordContext& rhs);

  void operator=(MarkWordContext rhs);

  ~MarkWordContext();

};

typedef SaveRestore<oop, ContextStore<oop, MarkWordContext> > SaveRestoreMarkWords;

class ClassLoaderData;

class CLDClaimContext {

 private:

  ClassLoaderData* _cld;

  void swap(CLDClaimContext& rhs);

 public:

  CLDClaimContext();

  CLDClaimContext(ClassLoaderData* cld);

  CLDClaimContext(const CLDClaimContext& rhs);

  void operator=(CLDClaimContext rhs);

  ~CLDClaimContext();

};

typedef SaveRestore<ClassLoaderData*, ContextStore<ClassLoaderData*, CLDClaimContext> > SaveRestoreCLDClaimState;

class CLDClaimStateClosure : public CLDClosure {

 private:

  SaveRestoreCLDClaimState _state;

 public:

  CLDClaimStateClosure();

  void do_cld(ClassLoaderData* cld);

};

class SaveRestoreCLDClaimBits : public StackObj {

 private:

  CLDClaimStateClosure _claim_state_closure;

 public:

  SaveRestoreCLDClaimBits();

  ~SaveRestoreCLDClaimBits();

};

#endif // SHARE_JFR_LEAKPROFILER_UTILITIES_SAVERESTORE_HPP