attachrpl.c

extremeDB s sample code,useful for you

/*****************************************************************
 *                                                               *
 *  attachrpl.c                                                  *
 *                                                               *
 * This file is a part of the eXtremeDB-HA Application Framework *
 *   It contains the realization of a thread that attaches       *  
 * replicas to master.                                           *
 *                                                              *
 *****************************************************************
 *  Copyright (c) 2001-2006 McObject LLC                         * 
 *  All Rights Reserved                                          *
 *****************************************************************/
/*
 * ++
 * 
 * PROJECT:   eXtremeDB-HA Application Framework
 *
 * SUBSYSTEM: HA support
 *
 * MODULE:    ATTACHRPL.C
 *
 * ABSTRACT:  Replica creation thread
 *
 *
 * VERSION:   1.0
 *
 * HISTORY:
 *            1.0- 1 AD     01-Mar-2003 Created it was
 *                 2 AG     19-Mar-2003 Ported to Linux
 *                 3 SS     19-Jul-2003 Reconstructed
 *
 * --
 */
#define INCLUDE_SOCKETS
#include  "app.h"

extern  timer_unit    init_time;
extern  int           master_number;
extern  int           main_master;
extern  long          stop_flag;

extern  void ExitHandler(int errcode);

/*
 * This structure describes timeouts that are necessary to set the finite times to functions
 * of attaching and detaching replicas and of transaction commits
 */
static mco_connection_param_t master_conpar =
{
  TM_MASTER_COMMIT,   
  TM_ATTACH_REPLICA,
  TM_DETACH_REPLICA,
  TM_WAIT_FOR_DATA,
  TM_SYNCH,
  0               //replica_notifying
#ifdef MCO_CFG_HA_2PHASE_COMMIT /* special commit interface */
  ,0              // set Replica Fail Callback */
#endif //MCO_CFG_HA_2PHASE_COMMIT

};

/* 
 * The thread opens a channel for listening the connections requests from replicas.
 * It is always waiting for the requests. For this purpose it calls the  function
 *
 *      mco_nw_attach_replica().
 *
 *    This function is dependent on communication protocol therefore it is implemented in 
 * protocol dependent modules (appnwfio.c appnwpip.c appnwTCP.c appnwUDP.c).

 *
 *   Once the thread receives the request it creates the communication channel and calls
 * function mco_HA_attach_replica() in order to create copy of master's database on
 * replica side (also see mco_nw_attach_replica() and mco_nw_attach_master()).
 */

THREAD_PROC_DEFINE(ListenToReplicas, p)
{
  ha_h	              ha = (ha_h)p;     // HA instance handle
  MCO_RET             ret;              // result code
  int                 count;            // working cell
  mco_db_h            dbh;

  THREAD_PROC_MODE();

  Printf( "Master: Thread ListenToReplicas() started\n");

  ;
  if((ret = mco_db_connect(ha->dbName, &dbh)) != MCO_S_OK) {
    Printf( "Master: Can't connect to database error = %d\n", ret);
    EXIT(-1);
  }


  strcpy(ha->endpoint, nw_MasterName);
  sprintf(&ha->endpoint[strlen(ha->endpoint)-2],"%02d", ha->id*10);

/*
 * The infinite cycle for listening connection requests from replicas and creating copies of 
 * the master's database
 */
  for(;;)
  {
/*
 * mco_nw_attach_replica() -
 * Creates a communication channel and creates copy of master's database on replication side
 */
    ret = mco_nw_attach_replica(
                      dbh,
                      ha->endpoint,
                      &master_conpar,
                      0,
                      TM_ACCEPT_TIMEOUT,
                      (PVOID)ha
                      );
    if ( ret )
    {
      if(ret != MCO_E_NW_TIMEOUT) {
        Printf( "\nMaster: failed with error %d\n", ret );
        switch(ret) {
            case MCO_E_NW_KILLED_BY_REPLICA:
              Printf("\n\n*** master is killed by replica ***\n");
              stop_flag++;
              return;
            case MCO_E_NW_FATAL:
            case MCO_E_NW_NOTSUPP:
            case MCO_E_NW_BUSY:
            case MCO_E_NW_NOMEM:
            exit(-1);
            default:    break;
        }
      }
    }
    else {
      nw_channel_h ch;
      count = mco_HA_get_number_of_replicas(ha->db)-1;  // show current number of replicas
      ch = (nw_channel_h)mco_HA_get_io_channel(ha->db, (int2)(count));

#if defined( CFG_TCP_SOCKET_CHANNEL ) || defined( CFG_UDP_SOCKET_CHANNEL )
      printf("IP = %s\n", inet_ntoa(ch->sin.sin_addr));
#endif //defined( CFG_TCP_SOCKET_CHANNEL ) || defined( CFG_UDP_SOCKET_CHANNEL )
      Printf("*** attached (%d), time of initialization phase = %ld ms ***\n", count,init_time);
    }
  }
}
THREAD_PROC_FINISH_DEFINE