| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.jdbc.TransactionResourceImpl |
| 4 | |
| 5 | Copyright 1999, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.impl.jdbc; |
| 22 | |
| 23 | import org.apache.derby.jdbc.InternalDriver; |
| 24 | |
| 25 | import org.apache.derby.iapi.services.context.Context; |
| 26 | import org.apache.derby.iapi.services.context.ContextService; |
| 27 | import org.apache.derby.iapi.services.context.ContextManager; |
| 28 | import org.apache.derby.iapi.services.monitor.Monitor; |
| 29 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 30 | |
| 31 | import org.apache.derby.iapi.db.Database; |
| 32 | import org.apache.derby.iapi.error.StandardException; |
| 33 | import org.apache.derby.iapi.sql.conn.LanguageConnectionContext; |
| 34 | import org.apache.derby.iapi.error.ExceptionSeverity; |
| 35 | |
| 36 | import org.apache.derby.iapi.reference.Attribute; |
| 37 | import org.apache.derby.iapi.reference.SQLState; |
| 38 | import org.apache.derby.iapi.reference.Property; |
| 39 | import org.apache.derby.iapi.util.StringUtil; |
| 40 | import org.apache.derby.iapi.util.IdUtil; |
| 41 | |
| 42 | import java.util.Properties; |
| 43 | import java.sql.SQLException; |
| 44 | |
| 45 | /** |
| 46 | * An instance of a TransactionResourceImpl is a bundle of things that |
| 47 | * connects a connection to the database - it is the transaction "context" in |
| 48 | * a generic sense. It is also the object of synchronization used by the |
| 49 | * connection object to make sure only one thread is accessing the underlying |
| 50 | * transaction and context. |
| 51 | * |
| 52 | * <P>TransactionResourceImpl not only serves as a transaction "context", it |
| 53 | * also takes care of: <OL> |
| 54 | * <LI>context management: the pushing and popping of the context manager in |
| 55 | * and out of the global context service</LI> |
| 56 | * <LI>transaction demarcation: all calls to commit/abort/prepare/close a |
| 57 | * transaction must route thru the transaction resource. |
| 58 | * <LI>error handling</LI> |
| 59 | * </OL> |
| 60 | * |
| 61 | * <P>The only connection that have access to the TransactionResource is the |
| 62 | * root connection, all other nested connections (called proxyConnection) |
| 63 | * accesses the TransactionResource via the root connection. The root |
| 64 | * connection may be a plain EmbedConnection, or a DetachableConnection (in |
| 65 | * case of a XATransaction). A nested connection must be a ProxyConnection. |
| 66 | * A proxyConnection is not detachable and can itself be a XA connection - |
| 67 | * although an XATransaction may start nested local (proxy) connections. |
| 68 | * |
| 69 | * <P> this is an example of how all the objects in this package relate to each |
| 70 | * other. In this example, the connection is nested 3 deep. |
| 71 | * DetachableConnection. |
| 72 | * <P><PRE> |
| 73 | * |
| 74 | * lcc cm database jdbcDriver |
| 75 | * ^ ^ ^ ^ |
| 76 | * | | | | |
| 77 | * |======================| |
| 78 | * | TransactionResource | |
| 79 | * |======================| |
| 80 | * ^ | |
| 81 | * | | |
| 82 | * | | |---------------rootConnection----------| |
| 83 | * | | | | |
| 84 | * | | |- rootConnection-| | |
| 85 | * | | | | | |
| 86 | * | V V | | |
| 87 | *|========================| |=================| |=================| |
| 88 | *| EmbedConnection | | EmbedConnection | | EmbedConnection | |
| 89 | *| |<-----| |<-----| | |
| 90 | *| (DetachableConnection) | | ProxyConnection | | ProxyConnection | |
| 91 | *|========================| |=================| |=================| |
| 92 | * ^ | ^ ^ ^ |
| 93 | * | | | | | |
| 94 | * ---rootConnection-- | | | |
| 95 | * | | | |
| 96 | * | | | |
| 97 | * |======================| |======================| |======================| |
| 98 | * | ConnectionChild | | ConnectionChild | | ConnectionChild | |
| 99 | * | | | | | | |
| 100 | * | (EmbedStatement) | | (EmbedResultSet) | | (...) | |
| 101 | * |======================| |======================| |======================| |
| 102 | * |
| 103 | * <P>A plain local connection <B>must</B> be attached (doubly linked with) to a |
| 104 | * TransactionResource at all times. A detachable connection can be without a |
| 105 | * TransactionResource, and a TransactionResource for an XATransaction |
| 106 | * (called XATransactionResource) can be without a connection. |
| 107 | * |
| 108 | * |
| 109 | */ |
| 110 | public final class TransactionResourceImpl |
| 111 | { |
| 112 | /* |
| 113 | ** instance variables set up in the constructor. |
| 114 | */ |
| 115 | // conn is only present if TR is attached to a connection |
| 116 | protected ContextManager cm; |
| 117 | protected ContextService csf; |
| 118 | protected String username; |
| 119 | |
| 120 | private String dbname; |
| 121 | private InternalDriver driver; |
| 122 | private String url; |
| 123 | private String drdaID; |
| 124 | |
| 125 | // set these up after constructor, called by EmbedConnection |
| 126 | protected Database database; |
| 127 | protected LanguageConnectionContext lcc; |
| 128 | |
| 129 | /* |
| 130 | * create a brand new connection for a brand new transaction |
| 131 | */ |
| 132 | TransactionResourceImpl( |
| 133 | InternalDriver driver, |
| 134 | String url, |
| 135 | Properties info) throws SQLException |
| 136 | { |
| 137 | this.driver = driver; |
| 138 | csf = driver.getContextServiceFactory(); |
| 139 | dbname = InternalDriver.getDatabaseName(url, info); |
| 140 | this.url = url; |
| 141 | |
| 142 | // the driver manager will push a user name |
| 143 | // into the properties if its getConnection(url, string, string) |
| 144 | // interface is used. Thus, we look there first. |
| 145 | // Default to APP. |
| 146 | username = IdUtil.getUserNameFromURLProps(info); |
| 147 | |
| 148 | drdaID = info.getProperty(Attribute.DRDAID_ATTR, null); |
| 149 | |
| 150 | // make a new context manager for this TransactionResource |
| 151 | |
| 152 | // note that the Database API requires that the |
| 153 | // getCurrentContextManager call return the context manager |
| 154 | // associated with this session. The JDBC driver assumes |
| 155 | // responsibility (for now) for tracking and installing |
| 156 | // this context manager for the thread, each time a database |
| 157 | // call is made. |
| 158 | cm = csf.newContextManager(); |
| 159 | } |
| 160 | |
| 161 | /* |
| 162 | * Called only in EmbedConnection construtor. |
| 163 | * The Local Connection sets up the database in its constructor and sets it |
| 164 | * here. |
| 165 | */ |
| 166 | void setDatabase(Database db) |
| 167 | { |
| 168 | if (SanityManager.DEBUG) |
| 169 | SanityManager.ASSERT(database == null, |
| 170 | "setting database when it is not null"); |
| 171 | |
| 172 | database = db; |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * Called only in EmbedConnection constructor. Create a new transaction |
| 177 | * by creating a lcc. |
| 178 | * |
| 179 | * The arguments are not used by this object, it is used by |
| 180 | * XATransactionResoruceImpl. Put them here so that there is only one |
| 181 | * routine to start a local connection. |
| 182 | */ |
| 183 | void startTransaction() throws StandardException, SQLException |
| 184 | { |
| 185 | // setting up local connection |
| 186 | lcc = database.setupConnection(cm, username, drdaID, dbname); |
| 187 | } |
| 188 | |
| 189 | /* |
| 190 | * Return instance variables to EmbedConnection. RESOLVE: given time, we |
| 191 | * should perhaps stop giving out reference to these things but instead use |
| 192 | * the transaction resource itself. |
| 193 | */ |
| 194 | InternalDriver getDriver() { |
| 195 | return driver; |
| 196 | } |
| 197 | ContextService getCsf() { |
| 198 | return csf; |
| 199 | } |
| 200 | |
| 201 | /* |
| 202 | * need to be public because it is in the XATransactionResource interface |
| 203 | */ |
| 204 | ContextManager getContextManager() { |
| 205 | return cm; |
| 206 | } |
| 207 | |
| 208 | LanguageConnectionContext getLcc() { |
| 209 | return lcc; |
| 210 | } |
| 211 | String getDBName() { |
| 212 | return dbname; |
| 213 | } |
| 214 | String getUrl() { |
| 215 | return url; |
| 216 | } |
| 217 | Database getDatabase() { |
| 218 | return database; |
| 219 | } |
| 220 | |
| 221 | StandardException shutdownDatabaseException() { |
| 222 | StandardException se = StandardException.newException(SQLState.SHUTDOWN_DATABASE, getDBName()); |
| 223 | se.setReport(StandardException.REPORT_NEVER); |
| 224 | return se; |
| 225 | } |
| 226 | |
| 227 | /* |
| 228 | * local transaction demarcation - note that global or xa transaction |
| 229 | * cannot commit thru the connection, they can only commit thru the |
| 230 | * XAResource, which uses the xa_commit or xa_rollback interface as a |
| 231 | * safeguard. |
| 232 | */ |
| 233 | void commit() throws StandardException |
| 234 | { |
| 235 | lcc.userCommit(); |
| 236 | } |
| 237 | |
| 238 | void rollback() throws StandardException |
| 239 | { |
| 240 | // lcc may be null if this is called in close. |
| 241 | if (lcc != null) |
| 242 | lcc.userRollback(); |
| 243 | } |
| 244 | |
| 245 | /* |
| 246 | * context management |
| 247 | */ |
| 248 | |
| 249 | /** |
| 250 | * An error happens in the constructor, pop the context. |
| 251 | */ |
| 252 | void clearContextInError() |
| 253 | { |
| 254 | csf.resetCurrentContextManager(cm); |
| 255 | cm = null; |
| 256 | } |
| 257 | |
| 258 | /** |
| 259 | * Resolve: probably superfluous |
| 260 | */ |
| 261 | void clearLcc() |
| 262 | { |
| 263 | lcc = null; |
| 264 | } |
| 265 | |
| 266 | final void setupContextStack() |
| 267 | { |
| 268 | if (SanityManager.DEBUG) { |
| 269 | SanityManager.ASSERT(cm != null, "setting up null context manager stack"); |
| 270 | } |
| 271 | |
| 272 | csf.setCurrentContextManager(cm); |
| 273 | } |
| 274 | |
| 275 | final void restoreContextStack() { |
| 276 | |
| 277 | if ((csf == null) || (cm == null)) |
| 278 | return; |
| 279 | csf.resetCurrentContextManager(cm); |
| 280 | } |
| 281 | |
| 282 | /* |
| 283 | * exception handling |
| 284 | */ |
| 285 | |
| 286 | /* |
| 287 | * clean up the error and wrap the real exception in some SQLException. |
| 288 | */ |
| 289 | final SQLException handleException(Throwable thrownException, |
| 290 | boolean autoCommit, |
| 291 | boolean rollbackOnAutoCommit) |
| 292 | throws SQLException |
| 293 | { |
| 294 | try { |
| 295 | if (SanityManager.DEBUG) |
| 296 | SanityManager.ASSERT(thrownException != null); |
| 297 | |
| 298 | /* |
| 299 | just pass SQL exceptions right back. We assume that JDBC driver |
| 300 | code has cleaned up sufficiently. Not passing them through would mean |
| 301 | that all cleanupOnError methods would require knowledge of Utils. |
| 302 | */ |
| 303 | if (thrownException instanceof SQLException) { |
| 304 | |
| 305 | return (SQLException) thrownException; |
| 306 | |
| 307 | } |
| 308 | |
| 309 | boolean checkForShutdown = false; |
| 310 | if (thrownException instanceof StandardException) |
| 311 | { |
| 312 | StandardException se = (StandardException) thrownException; |
| 313 | int severity = se.getSeverity(); |
| 314 | if (severity <= ExceptionSeverity.STATEMENT_SEVERITY) |
| 315 | { |
| 316 | /* |
| 317 | ** If autocommit is on, then do a rollback |
| 318 | ** to release locks if requested. We did a stmt |
| 319 | ** rollback in the cleanupOnError above, but we still |
| 320 | ** may hold locks from the stmt. |
| 321 | */ |
| 322 | if (autoCommit && rollbackOnAutoCommit) |
| 323 | { |
| 324 | se.setSeverity(ExceptionSeverity.TRANSACTION_SEVERITY); |
| 325 | } |
| 326 | } else if (SQLState.CONN_INTERRUPT.equals(se.getMessageId())) { |
| 327 | // an interrupt closed the connection. |
| 328 | checkForShutdown = true; |
| 329 | } |
| 330 | } |
| 331 | // if cm is null, we don't have a connection context left, |
| 332 | // it was already removed. all that's left to cleanup is |
| 333 | // JDBC objects. |
| 334 | if (cm!=null) { |
| 335 | boolean isShutdown = cleanupOnError(thrownException); |
| 336 | if (checkForShutdown && isShutdown) { |
| 337 | // Change the error message to be a known shutdown. |
| 338 | thrownException = shutdownDatabaseException(); |
| 339 | } |
| 340 | } |
| 341 | |
| 342 | |
| 343 | |
| 344 | return wrapInSQLException((SQLException) null, thrownException); |
| 345 | |
| 346 | } catch (Throwable t) { |
| 347 | |
| 348 | if (cm!=null) { // something to let us cleanup? |
| 349 | cm.cleanupOnError(t); |
| 350 | } |
| 351 | /* |
| 352 | We'd rather throw the Throwable, |
| 353 | but then javac complains... |
| 354 | We assume if we are in this degenerate |
| 355 | case that it is actually a java exception |
| 356 | */ |
| 357 | throw wrapInSQLException((SQLException) null, t); |
| 358 | //throw t; |
| 359 | } |
| 360 | |
| 361 | } |
| 362 | |
| 363 | public static final SQLException wrapInSQLException(SQLException sqlException, Throwable thrownException) { |
| 364 | |
| 365 | if (thrownException == null) |
| 366 | return sqlException; |
| 367 | |
| 368 | SQLException nextSQLException; |
| 369 | |
| 370 | if (thrownException instanceof SQLException) { |
| 371 | |
| 372 | // server side JDBC can end up with a SQLException in the nested stack |
| 373 | nextSQLException = (SQLException) thrownException; |
| 374 | } |
| 375 | else if (thrownException instanceof StandardException) { |
| 376 | |
| 377 | StandardException se = (StandardException) thrownException; |
| 378 | |
| 379 | nextSQLException = Util.generateCsSQLException(se); |
| 380 | |
| 381 | wrapInSQLException(nextSQLException, se.getNestedException()); |
| 382 | |
| 383 | } else { |
| 384 | |
| 385 | nextSQLException = Util.javaException(thrownException); |
| 386 | |
| 387 | // special case some java exceptions that have nested exceptions themselves |
| 388 | Throwable nestedByJVM = null; |
| 389 | if (thrownException instanceof ExceptionInInitializerError) { |
| 390 | nestedByJVM = ((ExceptionInInitializerError) thrownException).getException(); |
| 391 | } else if (thrownException instanceof java.lang.reflect.InvocationTargetException) { |
| 392 | nestedByJVM = ((java.lang.reflect.InvocationTargetException) thrownException).getTargetException(); |
| 393 | } |
| 394 | |
| 395 | if (nestedByJVM != null) { |
| 396 | wrapInSQLException(nextSQLException, nestedByJVM); |
| 397 | } |
| 398 | |
| 399 | } |
| 400 | |
| 401 | if (sqlException != null) { |
| 402 | sqlException.setNextException(nextSQLException); |
| 403 | } |
| 404 | |
| 405 | return nextSQLException; |
| 406 | } |
| 407 | |
| 408 | /* |
| 409 | * TransactionResource methods |
| 410 | */ |
| 411 | |
| 412 | String getUserName() { |
| 413 | return username; |
| 414 | } |
| 415 | |
| 416 | boolean cleanupOnError(Throwable e) |
| 417 | { |
| 418 | if (SanityManager.DEBUG) |
| 419 | SanityManager.ASSERT(cm != null, "cannot cleanup on error with null context manager"); |
| 420 | |
| 421 | return cm.cleanupOnError(e); |
| 422 | } |
| 423 | |
| 424 | boolean isIdle() |
| 425 | { |
| 426 | // If no lcc, there is no transaction. |
| 427 | return (lcc == null || lcc.getTransactionExecute().isIdle()); |
| 428 | } |
| 429 | |
| 430 | |
| 431 | /* |
| 432 | * class specific methods |
| 433 | */ |
| 434 | |
| 435 | |
| 436 | /* |
| 437 | * is the underlaying database still active? |
| 438 | */ |
| 439 | boolean isActive() |
| 440 | { |
| 441 | // database is null at connection open time |
| 442 | return (driver.isActive() && ((database == null) || database.isActive())); |
| 443 | } |
| 444 | |
| 445 | } |
| 446 | |
| 447 | |