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 #include<Process.h>
  24
  25 void TransactionManager::printUsageStatistics()
  26 {
  27     Transaction *iter = firstTrans;
  28     int i=0, usedCount =0, freeCount =0, undoLogCount=0;
  29     for (; i < Conf::config.getMaxProcs(); i++)
  30     {
  31             if (iter->status_ == TransNotUsed) freeCount++;
  32             else
  33             {
  34                 usedCount++;
  35                 undoLogCount += iter->noOfUndoLogs();
  36             }
  37             iter++;
  38     }
  39     printf("<TransactionTable>\n");
  40     printf("  <UsedSlots> %d </UsedSlots>\n", usedCount);
  41     printf("  <FreeSlots> %d </FreeSlots>\n", freeCount);
  42
  43     printf("  <UndoLogs>\n");
  44     printf("    <TotalNodes> %d </TotalNodes>\n", undoLogCount);
  45     printf("  </UndoLogs>\n");
  46     printf("</TransactionTable>\n");
  47
  48 }
  49
  50 void TransactionManager::printDebugInfo(Database *sysdb)
  51 {
  52     Transaction *iter = firstTrans;
  53     int i=0, usedCount =0, freeCount =0, undoLogCount=0;
  54     printf("<TransactionTable>\n");
  55     for (; i < Conf::config.getMaxProcs(); i++)
  56     {
  57             if (iter->status_ == TransNotUsed) freeCount++;
  58             else
  59             {
  60                 usedCount++;
  61                 undoLogCount += iter->noOfUndoLogs();
  62                 iter->printDebugInfo(sysdb);
  63             }
  64             iter++;
  65     }
  66
  67     printf("  <UsedSlots> %d </UsedSlots>\n", usedCount);
  68     printf("  <FreeSlots> %d </FreeSlots>\n", freeCount);
  69
  70     printf("  <UndoLogs>\n");
  71     printf("    <TotalNodes> %d </TotalNodes>\n", undoLogCount);
  72     printf("  </UndoLogs>\n");
  73     printf("</TransactionTable>\n");
  74 }
  75
  76
  77 DbRetVal TransactionManager::startTransaction(LockManager *lMgr, IsolationLevel level)
  78 {
  79     Database *sysdb = lMgr->systemDatabase_;
  80     Transaction *trans = ProcessManager::getThreadTransaction(sysdb->procSlot);
  81     if (NULL != trans)
  82     {
  83         if (trans->status_ != TransNotUsed) return ErrAlready;
  84         else {
  85             //the previous transaction shall be used again
  86             trans->status_ = TransRunning;
  87             trans->isoLevel_ = level;
  88             printDebug(DM_Transaction, "Using the same transaction slot\n");
  89             return OK;
  90         }
  91
  92     }
  93
  94     DbRetVal rv = sysdb->getTransTableMutex();
  95     if (OK != rv)
  96     {
  97         printError(ErrSysInternal, "Unable to acquire transtable mutex");
  98         return ErrSysInternal;
  99     }
 100     Transaction *iter = firstTrans;
 101     int i;
 102     for (i =0 ; i < Conf::config.getMaxProcs(); i++)
 103     {
 104             if (iter->status_ == TransNotUsed) break;
 105             iter++;
 106     }
 107     // if Transaction table is full return error
 108     if (i == Conf::config.getMaxProcs()) {
 109         printError(ErrNoResource, "Transaction slots are full");
 110         sysdb->releaseTransTableMutex();
 111         return ErrNoResource;
 112     }
 113     printDebug(DM_Transaction, "Using transaction slot %d \n", i);
 114
 115     //Make this free slot, as the current transaction and
 116     //set the state
 117     trans = iter;
 118     trans->status_ = TransRunning;
 119     trans->isoLevel_ = level;
 120     sysdb->releaseTransTableMutex();
 121     ProcessManager::setThreadTransaction(trans, sysdb->procSlot);
 122     return OK;
 123 }
 124
 125 void TransactionManager::setFirstTrans(Transaction *trans)
 126 {
 127     firstTrans = trans;
 128 }
 129
 130
 131 DbRetVal TransactionManager::commit(LockManager *lockManager)
 132 {
 133     Database *sysdb = lockManager->systemDatabase_;
 134     Transaction *trans = ProcessManager::getThreadTransaction(sysdb->procSlot);
 135     if (NULL == trans)
 136     {
 137        printError(ErrNotOpen, "No transaction started for this procSlot %d", sysdb->procSlot);
 138        return ErrNotOpen;
 139     }
 140     DbRetVal rv = sysdb->getTransTableMutex();
 141     if (OK != rv)
 142     {
 143         printError(ErrSysInternal, "Unable to acquire transtable mutex");
 144         return ErrSysInternal;
 145     }
 146
 147     if (trans->status_ != TransRunning)
 148     {
 149         sysdb->releaseTransTableMutex();
 150         printError(ErrBadCall, "Transaction is not in running state\n");
 151         return ErrBadCall;
 152     }
 153     trans->status_ = TransCommitting;
 154     sysdb->releaseTransTableMutex();
 155
 156     trans->releaseAllLocks(lockManager);
 157     if(NULL != trans->waitLock_)
 158     {
 159             printError(ErrSysInternal, "Trans WaitLock is not null\n");
 160             return ErrSysInternal;
 161     }
 162     //TODO::flush all redo logs to disk
 163     //TODO::remove all the logs in memory
 164     trans->removeUndoLogs(sysdb);
 165     rv = sysdb->getTransTableMutex();
 166     if (OK != rv)
 167     {
 168         printError(ErrSysInternal, "Unable to acquire transtable mutex");
 169         return ErrSysInternal;
 170     }
 171     trans->status_ = TransNotUsed;
 172     sysdb->releaseTransTableMutex();
 173     printDebug(DM_Transaction, "Committed transaction:%x",trans);
 174     return OK;
 175 }
 176
 177 DbRetVal TransactionManager::rollback(LockManager *lockManager, Transaction *t)
 178 {
 179     Database *sysdb = lockManager->systemDatabase_;
 180     Transaction *trans;
 181     if (t == NULL)
 182         trans = ProcessManager::getThreadTransaction(sysdb->procSlot);
 183     else
 184         trans = t;
 185     if (NULL == trans)
 186     {
 187        return OK;
 188     }
 189     DbRetVal rv= sysdb->getTransTableMutex();
 190     if (OK != rv)
 191     {
 192         printError(ErrSysInternal, "Unable to acquire transtable mutex");
 193         return ErrSysInternal;
 194     }
 195
 196     if (trans->status_ != TransRunning)
 197     {
 198         sysdb->releaseTransTableMutex();
 199         //will be called during connection disconnect without starting transaction.
 200         return OK;
 201     }
 202     trans->status_ = TransAborting;
 203     sysdb->releaseTransTableMutex();
 204
 205     trans->applyUndoLogs(sysdb);
 206     //TODO::remove all the logs in memory
 207     trans->releaseAllLocks(lockManager);
 208     if(NULL != trans->waitLock_)
 209     {
 210        printError(ErrSysInternal, "Trans waitlock is not null");
 211        return ErrSysInternal;
 212     }
 213
 214     sysdb->getTransTableMutex();
 215     trans->status_ = TransNotUsed;
 216     sysdb->releaseTransTableMutex();
 217     printDebug(DM_Transaction, "Aborted transaction:%x",trans);
 218
 219     return OK;
 220 }