src/server/TransactionManager.cxx

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by www.databasecache.com                           *
   3  *   Contact: praba_tuty@databasecache.com                                 *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15   ***************************************************************************/
  16 #include<Transaction.h>
  17 #include<Lock.h>
  18 #include<Database.h>
  19 #include<Allocator.h>
  20 #include<CatalogTables.h>
  21 #include<Debug.h>
  22 #include<Config.h>
  23 DbRetVal TransactionManager::startTransaction(IsolationLevel level)
  24 {
  25     if (NULL != trans)
  26     {
  27         if (trans->status_ == TransNotUsed)
  28         {
  29             //the previous transaction shall be used again
  30             trans->status_ = TransRunning;
  31             trans->isoLevel_ = level;
  32             return OK;
  33         }
  34     }
  35     Transaction *iter = firstTrans;
  36     //get free slot from transaction table
  37     for (int i =0 ; i < config.getMaxTrans(); i++)
  38     {
  39             if (iter->status_ == TransNotUsed) break;
  40             iter++;
  41         }
  42     //Make this free slot, as the current transaction and
  43     //set the state
  44     trans = iter;
  45     trans->status_ = TransRunning;
  46     trans->isoLevel_ = level;
  47     return OK;
  48 }
  49
  50 void TransactionManager::setFirstTrans(Transaction *trans)
  51 {
  52     firstTrans = trans;
  53 }
  54
  55 DbRetVal TransactionManager::commit(LockManager *lockManager_)
  56 {
  57     Database *sysdb = lockManager_->systemDatabase_;
  58     sysdb->getTransTableMutex();
  59     if (trans->status_ != TransRunning)
  60     {
  61         printError(ErrBadCall, "Transaction is not in running state\n");
  62         return ErrBadCall;
  63     }
  64     trans->status_ = TransCommitting;
  65     sysdb->releaseTransTableMutex();
  66
  67     trans->releaseAllLocks(lockManager_);
  68     if(NULL != trans->waitLock_)
  69     {
  70             printError(ErrSysInternal, "Trans WaitLock is not null\n");
  71             return ErrSysInternal;
  72     }
  73     //TODO::flush all redo logs to disk
  74     //TODO::remove all the logs in memory
  75     trans->removeUndoLogs(sysdb);
  76     sysdb->getTransTableMutex();
  77     trans->status_ = TransNotUsed;
  78     sysdb->releaseTransTableMutex();
  79     printDebug(DM_Transaction, "Committed transaction:%x",trans);
  80     return OK;
  81 }
  82
  83 DbRetVal TransactionManager::rollback(LockManager *lockManager_)
  84 {
  85     Database *sysdb = lockManager_->systemDatabase_;
  86     sysdb->getTransTableMutex();
  87     if (trans->status_ != TransRunning)
  88     {
  89         printError(ErrBadCall, "Transaction is not in running state\n");
  90         return ErrBadCall;
  91     }
  92     trans->status_ = TransAborting;
  93     sysdb->releaseTransTableMutex();
  94
  95     trans->applyUndoLogs(sysdb);
  96     //TODO::remove all the logs in memory
  97     trans->releaseAllLocks(lockManager_);
  98     if(NULL != trans->waitLock_)
  99     {
 100        printError(ErrSysInternal, "Trans waitlock is not null");
 101        return ErrSysInternal;
 102     }
 103
 104     sysdb->getTransTableMutex();
 105     trans->status_ = TransNotUsed;
 106     sysdb->releaseTransTableMutex();
 107     printDebug(DM_Transaction, "Aborted transaction:%x",trans);
 108
 109     return OK;
 110 }