/*

 * Copyright (c) 2014, 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_UTILITIES_JFRTRYLOCK_HPP

#define SHARE_JFR_UTILITIES_JFRTRYLOCK_HPP

#include "runtime/atomic.hpp"

#include "runtime/orderAccess.hpp"

#include "runtime/mutexLocker.hpp"

#include "utilities/debug.hpp"

class JfrTryLock {

 private:

  volatile int* const _lock;

  bool _has_lock;

 public:

  ~JfrTryLock() {

    if (_has_lock) {

      OrderAccess::fence();

      *_lock = 0;

    }

  }

  bool has_lock() const {

    return _has_lock;

  }

};

class JfrMonitorTryLock : public StackObj {

 private:

  Monitor* _lock;

  bool _acquired;

 public:

  JfrMonitorTryLock(Monitor* lock) : _lock(lock), _acquired(lock->try_lock()) {}

  ~JfrMonitorTryLock() {

    if (_acquired) {

      assert(_lock->owned_by_self(), "invariant");

      _lock->unlock();

    }

  }

  bool acquired() const {

    return _acquired;

  }

};

#endif // SHARE_JFR_UTILITIES_JFRTRYLOCK_HPP