shrcommit.c

extremeDB s sample code,useful for you

/*******************************************************************
 *                                                                 *
 *  shrcommit.c                                                    *
 *                                                                 *
 *  This file is a part of the eXtremeDB HA framework              *
 *  Copyright (c) 2001-2006 McObject LLC                           * 
 *  All Rights Reserved                                            *
 *                                                                 *
 *******************************************************************/
/*
 * ++
 * 
 * PROJECT:   eXtremeDB(tm) (c) McObject LLC
*
 * SUBSYSTEM: HA support
 *
 * MODULE:    shrcommit.c
 *
 * ABSTRACT:  Shared commit thread for multiprocess commit
 *
 *
 * VERSION:   1.0
 *
 * HISTORY:
 *            1.0- 1 SS     19-Oct-2003 Created it was
 *
 * --
 */

#include "app.h"
#include "mcoHA.h"
#include "watchdog.h"

#ifdef CFG_SHARED_COMMIT

/*
 * If you wish to use HA with several master processes accessing the
 * shared memory database in your own implementation of the communication channel,
 * you should create a separate thread in the 'main' master process in order to implement
 * the "shared commit". This thread should call mco_HA_trans_commit_synch() function.
 * Note that the mco_HA_trans_commit_synch()  will return an error if the shared commit
 * has not been initialized yet. If the shared commit mode has been set the function enters
 * the internal loop and never return control back to the application
 * (see the thread SynchCommit() in modules appnw... .c)
 * You must set the shared commit mode via mco_HA_set_mode () function.
 * In order to set this mode set the par.is_master field to
 * MCO_MULTIPROCESS_COMMIT.
 */

extern MUTEX_T    mutex;

THREAD_ID         synchcommit = (THREAD_ID)-1;

THREAD_PROC_DEFINE(SynchCommit, p)
{
  int i;
  mco_db_h db = (mco_db_h)p;
  MCO_RET rc;

    THREAD_PROC_MODE();

    Printf("Master: shared commit started\n");
    MUTEX_UNLOCK(&mutex);

    /* wait 3 seconds until master shared commit mode is initialized */

    for(i = 0; i< 60 ; i++) {

      if ((rc = mco_HA_trans_commit_synch( db )) != MCO_S_OK) 
                return; /* fatal error. The database isn't initialized yet */

      Sleep(50);
    }
}
THREAD_PROC_FINISH_DEFINE

#endif  //  CFG_SHARED_COMMIT