/*

 * Copyright (c) 2013, 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_RECORDER_SERVICE_JFRPOSTBOX_HPP

#define SHARE_JFR_RECORDER_SERVICE_JFRPOSTBOX_HPP

#include "jfr/utilities/jfrAllocation.hpp"

#define MSGBIT(e) (1<<(e))

enum JFR_Msg {

  MSG_ALL_MSGS = -1,

  MSG_CLONE_IN_MEMORY = 0,

  MSG_START,

  MSG_STOP,

  MSG_ROTATE,

  MSG_FULLBUFFER,

  MSG_CHECKPOINT,

  MSG_WAKEUP,

  MSG_SHUTDOWN,

  MSG_VM_ERROR,

  MSG_DEADBUFFER,

  MSG_NO_OF_MSGS

};

/**

 *  Jfr messaging.

 *

 *  Synchronous messages (posting thread waits for message completion):

 *

 *  MSG_CLONE_IN_MEMORY (0) ; MSGBIT(MSG_CLONE_IN_MEMORY) == (1 << 0) == 0x1

 *  MSG_START(1)            ; MSGBIT(MSG_START) == (1 << 0x1) == 0x2

 *  MSG_STOP (2)            ; MSGBIT(MSG_STOP) == (1 << 0x2) == 0x4

 *  MSG_ROTATE (3)          ; MSGBIT(MSG_ROTATE) == (1 << 0x3) == 0x8

 *

 *  Asynchronous messages (posting thread returns immediately upon deposit):

 *

 *  MSG_FULLBUFFER (4)      ; MSGBIT(MSG_FULLBUFFER) == (1 << 0x4) == 0x10

 */

class JfrPostBox : public JfrCHeapObj {

  friend class JfrRecorder;

 public:

  void post(JFR_Msg msg);

 private:

  uintptr_t _msg_read_serial;

  uintptr_t _msg_handled_serial;

  volatile int _messages;

  bool _has_waiters;

  JfrPostBox();

  static JfrPostBox& instance();

  static JfrPostBox* create();

  static void destroy();

  void asynchronous_post(int msg);

  void synchronous_post(int msg);

  void deposit(int new_messages);

  bool is_message_processed(uintptr_t serial_id) const;

  friend void recorderthread_entry(JavaThread*, Thread*);

  // for the friend declaration above

  bool is_empty() const;

  int collect();

  bool check_waiters(int messages) const;

  void notify_waiters();

  void notify_collection_stop();

};

#endif // SHARE_JFR_RECORDER_SERVICE_JFRPOSTBOX_HPP