/*

 * 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.

 *

 */

#ifndef SHARE_VM_GC_SHARED_GCID_HPP

#define SHARE_VM_GC_SHARED_GCID_HPP

#include "memory/allocation.hpp"

class GCId : public AllStatic {

private:

  friend class GCIdMark;

  static uint _next_id;

  static const uint UNDEFINED = (uint)-1;

  static uint create();

public:

  // Returns the currently active GC id. Asserts that there is an active GC id.

  static uint current();

  // Same as current() but can return undefined() if no GC id is currently active

  static uint current_or_undefined();

  // Returns the next expected GCId.

  static uint peek();

  static uint undefined() { return UNDEFINED; }

  static size_t print_prefix(char* buf, size_t len);

};

class GCIdMark : public StackObj {

private:

  const uint _previous_gc_id;

public:

  GCIdMark();

  GCIdMark(uint gc_id);

  ~GCIdMark();

};

#endif // SHARE_VM_GC_SHARED_GCID_HPP