Exception handling improvements

Assorted minor changes

h2/src/main/org/h2/engine/Database.java

@@ -808,7 +808,7 @@ public class Database implements DataHandler {
         }
         systemSession.commit(true);
         if (mvStore != null) {
-            mvStore.initTransactions();
+            mvStore.getTransactionStore().endLeftoverTransactions();
             mvStore.removeTemporaryMaps(objectIds);
         }
         recompileInvalidViews(systemSession);
@@ -1014,6 +1014,7 @@ public class Database implements DataHandler {
             SearchRow r = meta.getTemplateSimpleRow(false);
             r.setValue(0, ValueInt.get(id));
             boolean wasLocked = lockMeta(session);
+            try {
                 Cursor cursor = metaIdIndex.find(session, r, r);
                 if (cursor.next()) {
                     if (SysProperties.CHECK) {
@@ -1031,12 +1032,13 @@ public class Database implements DataHandler {
                     if (SysProperties.CHECK) {
                         checkMetaFree(session, id);
                     }
-            } else if (!wasLocked) {
-                unlockMetaDebug(session);
+                }
+            } finally {
+                if (!wasLocked) {
                     // must not keep the lock if it was not locked
                     // otherwise updating sequences may cause a deadlock
-                meta.unlock(session);
-                session.unlock(meta);
+                    unlockMeta(session);
+                }
             }
             objectIds.clear(id);
         }
@@ -1333,10 +1335,10 @@ public class Database implements DataHandler {
                     }
                     closing = true;
                 }
-            }
-            if(!this.isReadOnly()) {
+                if (!this.isReadOnly()) {
                     removeOrphanedLobs();
                 }
+            }
             try {
                 if (systemSession != null) {
                     if (powerOffCount != -1) {
@@ -1427,6 +1429,7 @@ public class Database implements DataHandler {
      * @param flush whether writing is allowed
      */
     private synchronized void closeOpenFilesAndUnlock(boolean flush) {
+        try {
             stopWriter();
             if (pageStore != null) {
                 if (flush) {
@@ -1456,7 +1459,7 @@ public class Database implements DataHandler {
                 }
             }
             reconnectModified(false);
-        if (mvStore != null && !mvStore.getStore().isClosed()) {
+            if (mvStore != null && mvStore.getStore() != null && !mvStore.getStore().isClosed()) {
                 long maxCompactTime = dbSettings.maxCompactTime;
                 if (compactMode == CommandInterface.SHUTDOWN_COMPACT) {
                     mvStore.compactFile(dbSettings.maxCompactTime);
@@ -1467,6 +1470,14 @@ public class Database implements DataHandler {
                 }
                 mvStore.close(maxCompactTime);
             }
+            if (systemSession != null) {
+                systemSession.close();
+                systemSession = null;
+            }
+            if (lobSession != null) {
+                lobSession.close();
+                lobSession = null;
+            }
             closeFiles();
             if (persistent && lock == null &&
                     fileLockMethod != FileLockMethod.NO &&
@@ -1479,14 +1490,7 @@ public class Database implements DataHandler {
             if (persistent) {
                 deleteOldTempFiles();
             }
-        if (systemSession != null) {
-            systemSession.close();
-            systemSession = null;
-        }
-        if (lobSession != null) {
-            lobSession.close();
-            lobSession = null;
-        }
+        } finally {
             if (lock != null) {
                 if (fileLockMethod == FileLockMethod.SERIALIZED) {
                     // wait before deleting the .lock file,
@@ -1504,6 +1508,7 @@ public class Database implements DataHandler {
                 lock = null;
             }
         }
+    }
 
     private synchronized void closeFiles() {
         try {
@@ -1946,7 +1951,6 @@ public class Database implements DataHandler {
                             t.getSQL());
                 }
                 obj.removeChildrenAndResources(session);
-
             }
             removeMeta(session, id);
         }
@@ -2550,6 +2554,7 @@ public class Database implements DataHandler {
      * Immediately close the database.
      */
     public void shutdownImmediately() {
+        closing = true;
         setPowerOffCount(1);
         try {
             checkPowerOff();

h2/src/main/org/h2/mvstore/MVStore.java

@@ -511,9 +511,12 @@ public class MVStore {
             M map = (M) getMap(id);
             if (map == null) {
                 String configAsString = meta.get(MVMap.getMapKey(id));
-                if(configAsString != null) {
-                    HashMap<String, Object> config =
-                            new HashMap<String, Object>(DataUtils.parseMap(configAsString));
+                HashMap<String, Object> config;
+                if (configAsString != null) {
+                    config = new HashMap<String, Object>(DataUtils.parseMap(configAsString));
+                } else {
+                    config = new HashMap<>();
+                }
                 config.put("id", id);
                 map = builder.create(this, config);
                 map.init();
@@ -521,7 +524,6 @@ public class MVStore {
                 map.setRootPos(root, lastStoredVersion);
                 maps.put(id, map);
             }
-            }
             return map;
         } finally {
             storeLock.unlock();

h2/src/main/org/h2/mvstore/db/MVTableEngine.java

@@ -246,21 +246,6 @@ public class MVTableEngine implements TableEngine {
             store.closeImmediately();
         }
 
-        /**
-         * Commit all transactions that are in the committing state, and
-         * rollback all open transactions.
-         */
-        public void initTransactions() {
-            List<Transaction> list = transactionStore.getOpenTransactions();
-            for (Transaction t : list) {
-                if (t.getStatus() == Transaction.STATUS_COMMITTED) {
-                    t.commit();
-                } else if (t.getStatus() != Transaction.STATUS_PREPARED) {
-                    t.rollback();
-                }
-            }
-        }
-
         /**
          * Remove all temporary maps.
          *

h2/src/main/org/h2/mvstore/tx/TransactionStore.java

@@ -147,14 +147,6 @@ public class TransactionStore {
      */
     public void init() {
         if (!init) {
-            // remove all temporary maps
-            for (String mapName : store.getMapNames()) {
-                if (mapName.startsWith("temp.")) {
-                    MVMap<Object, Integer> temp = openTempMap(mapName);
-                    store.removeMap(temp);
-                }
-            }
-
             for (String mapName : store.getMapNames()) {
                 if (mapName.startsWith(UNDO_LOG_NAME_PEFIX)) {
                     if (store.hasData(mapName)) {
@@ -165,13 +157,15 @@ public class TransactionStore {
                             int status;
                             String name;
                             if (data == null) {
-                                status = mapName.charAt(UNDO_LOG_NAME_PEFIX.length()) == UNDO_LOG_OPEN ?
-                                        Transaction.STATUS_OPEN : Transaction.STATUS_COMMITTED;
+                                status = Transaction.STATUS_OPEN;
                                 name = null;
                             } else {
                                 status = (Integer) data[0];
                                 name = (String) data[1];
                             }
+                            if (mapName.charAt(UNDO_LOG_NAME_PEFIX.length()) == UNDO_LOG_COMMITTED) {
+                                status = Transaction.STATUS_COMMITTED;
+                            }
                             MVMap<Long, Object[]> undoLog = store.openMap(mapName, undoLogBuilder);
                             undoLogs[transactionId] = undoLog;
                             Long lastUndoKey = undoLog.lastKey();
@@ -187,6 +181,21 @@ public class TransactionStore {
         }
     }
 
+    /**
+     * Commit all transactions that are in the committed state, and
+     * rollback all open transactions.
+     */
+    public void endLeftoverTransactions() {
+        List<Transaction> list = getOpenTransactions();
+        for (Transaction t : list) {
+            if (t.getStatus() == Transaction.STATUS_COMMITTED) {
+                t.commit();
+            } else if (t.getStatus() != Transaction.STATUS_PREPARED) {
+                t.rollback();
+            }
+        }
+    }
+
     /**
      * Set the maximum transaction id, after which ids are re-used. If the old
      * transaction is still in use when re-using an old id, the new transaction