src/storage/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 || iter->status_ == TransReserved) 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 || iter->status_ == TransReserved) 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     Chunk *chunk = sysdb->getSystemDatabaseChunk(UndoLogTableID);
  71
  72     printf("  <UndoLogs>\n");
  73     printf("    <TotalNodes> %d </TotalNodes>\n", undoLogCount);
  74     printf("    <TotalPages> %d </TotalPages>\n", chunk->totalPages());
  75     printf("  </UndoLogs>\n");
  76     printf("</TransactionTable>\n");
  77 }
  78
  79
  80 DbRetVal TransactionManager::startTransaction(LockManager *lMgr, IsolationLevel level)
  81 {
  82     Database *sysdb = lMgr->systemDatabase_;
  83     Transaction *trans = ProcessManager::getThreadTransaction(sysdb->procSlot);
  84     if (NULL != trans)
  85     {
  86         //
  87         if (trans->status_ != TransReserved) return ErrAlready;
  88         else if (trans->status_ == TransReserved)
  89         {
  90             //the previous transaction shall be used again
  91             //trans->status_ = TransRunning;
  92             if ( 0 != Mutex::CASGen(&trans->status_, TransReserved, TransRunning)) {
  93                 printError(ErrLockTimeOut, "unable to get lock to reuse the transaction");
  94                 return ErrLockTimeOut;
  95             }
  96             trans->isoLevel_ = level;
  97             printDebug(DM_Transaction, "Using the same transaction slot\n");
  98             logFinest(Conf::logger, "Transaction Start:Reusing :%x", trans);
  99             return OK;
 100         }
 101
 102     }
 103
 104     DbRetVal rv = sysdb->getTransTableMutex();
 105     if (OK != rv)
 106     {
 107         printError(rv, "Unable to acquire transtable mutex");
 108         return rv;
 109     }
 110     Transaction *iter = firstTrans;
 111     int i;
 112     for (i =0 ; i < Conf::config.getMaxProcs(); i++)
 113     {
 114             if (iter->status_ == TransNotUsed) break;
 115             iter++;
 116     }
 117     // if Transaction table is full return error
 118     if (i == Conf::config.getMaxProcs()) {
 119         printError(ErrNoResource, "Transaction slots are full");
 120         sysdb->releaseTransTableMutex();
 121         return ErrNoResource;
 122     }
 123     printDebug(DM_Transaction, "Using transaction slot %d \n", i);
 124
 125     //Make this free slot, as the current transaction and
 126     //set the state
 127     trans = iter;
 128     //trans->status_ = TransRunning;
 129     if ( 0 != Mutex::CASGen(&trans->status_ , TransNotUsed, TransRunning)) {
 130         printError(ErrLockTimeOut, "Unable to start transaction. Timeout. Retry..");
 131         sysdb->releaseTransTableMutex();
 132         return ErrLockTimeOut;
 133     }
 134     trans->isoLevel_ = level;
 135     ProcessManager::setThreadTransaction(trans, sysdb->procSlot);
 136     sysdb->releaseTransTableMutex();
 137     logFinest(Conf::logger, "Transaction Start:Using :%x", trans);
 138     return OK;
 139 }
 140
 141 void TransactionManager::setFirstTrans(Transaction *trans)
 142 {
 143     firstTrans = trans;
 144 }
 145
 146
 147 DbRetVal TransactionManager::commit(LockManager *lockManager)
 148 {
 149     Database *sysdb = lockManager->systemDatabase_;
 150     Transaction *trans = ProcessManager::getThreadTransaction(sysdb->procSlot);
 151     DbRetVal rv = OK;
 152     if (NULL == trans)
 153     {
 154        printError(ErrNotOpen, "No transaction started for this procSlot %d", sysdb->procSlot);
 155        return ErrNotOpen;
 156     }
 157     rv = trans->releaseAllLocks(lockManager);
 158     if (rv != OK) {
 159         printError(ErrSysInternal, "Fatal:Unable to release all the locks\n");
 160     }
 161     if(NULL != trans->waitLock_)
 162     {
 163         printError(ErrSysInternal, "Fatal:Trans WaitLock is not null\n");
 164     }
 165     trans->removeUndoLogs(sysdb);
 166     if ( 0 != Mutex::CASGen(&trans->status_, TransRunning, TransReserved))
 167     {
 168         printError(ErrSysFatal, "Transaction state corrupted %d\n", trans->status_);
 169         return ErrSysFatal;
 170     }
 171     printDebug(DM_Transaction, "Committed transaction:%x",trans);
 172     logFinest(Conf::logger, "Transaction Committed:%x", trans);
 173     return OK;
 174 }
 175
 176 DbRetVal TransactionManager::rollback(LockManager *lockManager, Transaction *t)
 177 {
 178     Database *sysdb = lockManager->systemDatabase_;
 179     Transaction *trans = NULL;
 180     DbRetVal rv = OK;
 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
 190     if (trans->status_ != TransRunning)
 191     {
 192         //sysdb->releaseTransTableMutex();
 193         //will be called during connection disconnect without starting transaction.
 194         return OK;
 195     }
 196
 197     trans->applyUndoLogs(sysdb);
 198     rv = trans->releaseAllLocks(lockManager);
 199     if (rv != OK) {
 200         printError(ErrSysInternal, "Fatal:Unable to release all the locks");
 201     }
 202     if(NULL != trans->waitLock_)
 203     {
 204         printError(ErrSysInternal, "Fatal:Trans waitlock is not null");
 205         //return ErrSysInternal;
 206     }
 207
 208     //trans->status_ = TransNotUsed;
 209     if ( 0 != Mutex::CASGen(&trans->status_, TransRunning, TransReserved))
 210     {
 211         printError(ErrSysFatal, "Fatal:Unable to abort transaction %d\n", trans->status_);
 212         return ErrSysFatal;
 213     }
 214     printDebug(DM_Transaction, "Aborted transaction:%x",trans);
 215     logFinest(Conf::logger, "Transaction Aborted:%x", trans);
 216     return OK;
 217 }
 218 bool TransactionManager::isTransactionConsistent(Database *sysdb)
 219 {
 220     DbRetVal rv = sysdb->getTransTableMutex();
 221     if (OK != rv)
 222     {
 223         printError(rv, "Unable to acquire transtable mutex");
 224         return false;
 225     }
 226     Transaction *iter = firstTrans;
 227     int i;
 228     for (i =0 ; i < Conf::config.getMaxProcs(); i++)
 229     {
 230         if (iter->status_ == TransRunning && iter->noOfUndoLogs()) {
 231             printError( ErrSysInternal, "Transaction slot %d not consistent status:%d undoLogs:%d\n",i, iter->status_, iter->noOfUndoLogs());
 232             sysdb->releaseTransTableMutex();
 233             return false;
 234         }
 235         iter++;
 236     }
 237     sysdb->releaseTransTableMutex();
 238     return true;
 239 }