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00025 package org.objectweb.cjdbc.controller.scheduler.raidb1;
00026
00027 import java.sql.SQLException;
00028
00029 import org.objectweb.cjdbc.common.sql.AbstractWriteRequest;
00030 import org.objectweb.cjdbc.common.sql.ParsingGranularities;
00031 import org.objectweb.cjdbc.common.sql.SelectRequest;
00032 import org.objectweb.cjdbc.common.util.Constants;
00033 import org.objectweb.cjdbc.common.xml.DatabasesXmlTags;
00034 import org.objectweb.cjdbc.controller.requestmanager.RAIDbLevels;
00035 import org.objectweb.cjdbc.controller.scheduler.AbstractScheduler;
00036 import org.objectweb.cjdbc.controller.scheduler.schema.TransactionExclusiveLock;
00037
00038
00039
00040
00041
00042
00043
00044
00045
00046 public class RAIDb1PessimisticTransactionLevelScheduler
00047 extends AbstractScheduler
00048 {
00049
00050
00051
00052
00053
00054
00055
00056
00057
00058
00059
00060 private long requestId;
00061
00062 TransactionExclusiveLock lock = new TransactionExclusiveLock();
00063
00064
00065
00066
00067
00068
00069
00070
00071 public RAIDb1PessimisticTransactionLevelScheduler()
00072 {
00073 super(RAIDbLevels.RAIDb1, ParsingGranularities.NO_PARSING);
00074 }
00075
00076
00077
00078
00079
00080
00081
00082
00083
00084
00085
00086 public final void scheduleReadRequest(SelectRequest request)
00087 throws SQLException
00088 {
00089 synchronized (this)
00090 {
00091 request.setId(requestId++);
00092 }
00093 }
00094
00095
00096
00097
00098 public final void readCompletedNotify(SelectRequest request)
00099 {
00100 }
00101
00102
00103
00104
00105
00106
00107 public void scheduleNonSuspendedWriteRequest(AbstractWriteRequest request)
00108 throws SQLException
00109 {
00110 if (request.isCreate())
00111 {
00112 synchronized (this)
00113 {
00114 request.setId(requestId++);
00115 }
00116 return;
00117 }
00118
00119 if (lock.acquire(request))
00120 {
00121 synchronized (this)
00122 {
00123 request.setId(requestId++);
00124 }
00125 if (logger.isDebugEnabled())
00126 logger.debug("Request " + request.getId() + " scheduled for write ("
00127 + getPendingWrites() + " pending writes)");
00128 }
00129 else
00130 {
00131 if (logger.isWarnEnabled())
00132 logger.warn("Request " + request.getId() + " timed out ("
00133 + request.getTimeout() + " s)");
00134 throw new SQLException("Timeout (" + request.getTimeout()
00135 + ") for request: "
00136 + request.getSQLShortForm(Constants.SQL_SHORT_FORM_LENGTH));
00137 }
00138 }
00139
00140
00141
00142
00143 public final synchronized void notifyWriteCompleted(
00144 AbstractWriteRequest request)
00145 {
00146
00147
00148 if (request.isAutoCommit() && (!request.isCreate()))
00149 releaseLock(request.getTransactionId());
00150 }
00151
00152
00153
00154
00155
00156
00157
00158
00159 protected final void commitTransaction(long transactionId)
00160 {
00161 if (lock.isLocked())
00162 releaseLock(transactionId);
00163
00164 }
00165
00166
00167
00168
00169 protected final void rollbackTransaction(long transactionId)
00170 {
00171 if (lock.isLocked())
00172 releaseLock(transactionId);
00173
00174 }
00175
00176
00177
00178
00179
00180
00181 private void releaseLock(long transactionId)
00182 {
00183
00184 if (lock.isLocked())
00185 {
00186 if (lock.getLocker() == transactionId)
00187 lock.release();
00188
00189
00190
00191
00192 else if (logger.isDebugEnabled())
00193 logger.debug("Transaction " + transactionId
00194 + " wants to release the lock held by transaction "
00195 + lock.getLocker());
00196 }
00197 else if (logger.isDebugEnabled())
00198 logger.warn("Transaction " + transactionId
00199 + " tries to release a lock that has not been acquired.");
00200 }
00201
00202
00203
00204
00205
00206
00207
00208 public String getXmlImpl()
00209 {
00210 return "<" + DatabasesXmlTags.ELT_RAIDb1Scheduler + " "
00211 + DatabasesXmlTags.ATT_level + "=\""
00212 + DatabasesXmlTags.VAL_pessimisticTransaction + "\"/>";
00213 }
00214
00215 }