message_service.h

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/* Copyright (c) 2019, 2025, Oracle and/or its affiliates.
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.
 
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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   You should have received a copy of the GNU General Public License
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   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
 
#ifndef MESSAGE_SERVICE_H
#define MESSAGE_SERVICE_H
 
#include <mysql/components/service_implementation.h>
#include "plugin/group_replication/include/plugin_messages/group_service_message.h"
#include "plugin/group_replication/include/plugin_utils.h"
 
/**
  Register default send message service.
*/
bool register_gr_message_service_send();
 
/**
  Unregister default send message service.
*/
bool unregister_gr_message_service_send();
 
/**
  @class Message_service_handler
  Handles the deliver of recv service messages to subscribed modules.
*/
class Message_service_handler {
 public:
  /**
    Create a message service handler to deliver messages to recv subscribers.
  */
  Message_service_handler();
 
  virtual ~Message_service_handler();
 
  /**
     Initialize thread that will deliver messages.
 
     @return returns 0 if succeeds, error otherwise
  */
  int initialize();
 
  /**
     Main loop that checks message availability.
  */
  void dispatcher();
 
  /**
     Terminate delivering message thread.
 
     @return returns 0 if succeeds, error otherwise
  */
  int terminate();
 
  /**
     Add to queue a new message to be deliver to recv service subscribers.
 
     @param[in] message  message to be delivered
  */
  void add(Group_service_message *message);
 
  /**
    It will notify recv subscribers with a service message.
 
    @param[in] service_message  message to process
 
    @return false if message is delivered, true otherwise
  */
  bool notify_message_service_recv(Group_service_message *service_message);
 
 private:
  /** Thread was terminated */
  bool m_aborted;
  /** The current phase */
  my_thread_handle m_message_service_pthd;
  /** The thread lock to control access */
  mysql_mutex_t m_message_service_run_lock;
  /** The thread signal mechanism to be terminated */
  mysql_cond_t m_message_service_run_cond;
  /** The state of the thread. */
  thread_state m_message_service_thd_state;
  /** Queue with service message to be delivered */
  Abortable_synchronized_queue<Group_service_message *> *m_incoming;
};
 
#endif /* MESSAGE_SERVICE_H */