Row level locking for MVCC is now enabled.

h2/src/main/org/h2/command/Command.java

@@ -191,7 +191,7 @@ public abstract class Command implements CommandInterface {
     }
 
     public int executeUpdate() throws SQLException {
-        startTime = System.currentTimeMillis();
+        long start = startTime = System.currentTimeMillis();
         Database database = session.getDatabase();
         database.allocateReserveMemory();
         Object sync = database.getMultiThreaded() ? (Object) session : (Object) database;
@@ -200,14 +200,30 @@ public abstract class Command implements CommandInterface {
             int rollback = session.getLogId();
             session.setCurrentCommand(this, startTime);
             try {
-                database.checkPowerOff();
-                try {
-                    return update();
-                } catch (OutOfMemoryError e) {
-                    database.freeReserveMemory();
-                    throw Message.convert(e);
-                } catch (Throwable e) {
-                    throw Message.convert(e);
+                while (true) {
+                    database.checkPowerOff();
+                    try {
+                        return update();
+                    } catch (OutOfMemoryError e) {
+                        database.freeReserveMemory();
+                        throw Message.convert(e);
+                    } catch (SQLException e) {
+                        if (e.getErrorCode() == ErrorCode.CONCURRENT_UPDATE_1) {
+                            long now = System.currentTimeMillis();
+                            if (now - start > session.getLockTimeout()) {
+                                throw e;
+                            }
+                            try {
+                                database.wait(100);
+                            } catch (InterruptedException e1) {
+                                // ignore
+                            }
+                            continue;
+                        }
+                        throw e;
+                    } catch (Throwable e) {
+                        throw Message.convert(e);
+                    }
                 }
             } catch (SQLException e) {
                 database.exceptionThrown(e, sql);

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

@@ -341,13 +341,6 @@ public class Constants {
      */
     public static final int LOCK_MODE_READ_COMMITTED = 3;
     
-    /**
-     * The lock mode that means row level locks are used if possible.
-     * This lock mode is similar to read committed, but row level locks are
-     * used instead of table level locks.
-     */
-    public static final int LOCK_MODE_ROW = 4;
-    
     /**
      * The lock mode that means table level locking is used for reads and
      * writes.
@@ -366,12 +359,6 @@ public class Constants {
      * still exists once a database is locked.
      */
     public static final int LOCK_SLEEP = 1000;
-    
-    /**
-     * The divider used to calculate the minimum log file size as a function of
-     * the largest file (data file or index file).
-     */
-    public static final long LOG_SIZE_DIVIDER = 10;
 
     /**
      * The file header used for binary files.

h2/src/main/org/h2/jdbc/JdbcConnection.java

@@ -696,7 +696,6 @@ public class JdbcConnection extends TraceObject implements Connection {
                 transactionIsolationLevel = Connection.TRANSACTION_READ_UNCOMMITTED;
                 break;
             case Constants.LOCK_MODE_READ_COMMITTED:
-            case Constants.LOCK_MODE_ROW:
                 transactionIsolationLevel = Connection.TRANSACTION_READ_COMMITTED;
                 break;
             case Constants.LOCK_MODE_TABLE:

h2/src/main/org/h2/table/TableData.java

@@ -274,7 +274,6 @@ public class TableData extends Table implements RecordReader {
     }
 
     public void removeRow(Session session, Row row) throws SQLException {
-        lastModificationId = database.getNextModificationDataId();
         if (database.isMultiVersion()) {
             if (row.getDeleted()) {
                 throw Message.getSQLException(ErrorCode.CONCURRENT_UPDATE_1, getName());
@@ -287,6 +286,7 @@ public class TableData extends Table implements RecordReader {
                 throw Message.getSQLException(ErrorCode.CONCURRENT_UPDATE_1, getName());
             }
         }
+        lastModificationId = database.getNextModificationDataId();
         int i = indexes.size() - 1;
         try {
             for (; i >= 0; i--) {
@@ -377,7 +377,7 @@ public class TableData extends Table implements RecordReader {
                 }
             } else {
                 if (lockExclusive == null) {
-                    if (lockMode == Constants.LOCK_MODE_READ_COMMITTED || lockMode == Constants.LOCK_MODE_ROW) {
+                    if (lockMode == Constants.LOCK_MODE_READ_COMMITTED) {
                         if (!database.getMultiThreaded() && !database.isMultiVersion()) {
                             // READ_COMMITTED: a read lock is acquired, 
                             // but released immediately after the operation 

h2/src/test/org/h2/test/TestAll.java

@@ -75,6 +75,7 @@ import org.h2.test.jdbcx.TestXASimple;
 import org.h2.test.mvcc.TestMvcc1;
 import org.h2.test.mvcc.TestMvcc2;
 import org.h2.test.mvcc.TestMvcc3;
+import org.h2.test.mvcc.TestMvccMultiThreaded;
 import org.h2.test.rowlock.TestRowLocks;
 import org.h2.test.server.TestNestedLoop;
 import org.h2.test.server.TestPgServer;
@@ -272,6 +273,8 @@ java org.h2.test.TestAll timer
 
 /*
 
+row level locking for mvcc
+
 Run benchmark with the newest versions of other databases.
 documentation: use 'server mode' not 'remote mode'.
 
@@ -540,6 +543,7 @@ http://www.w3schools.com/sql/
         new TestMvcc1().runTest(this);
         new TestMvcc2().runTest(this);
         new TestMvcc3().runTest(this);
+        new TestMvccMultiThreaded().runTest(this);
         new TestRowLocks().runTest(this);
 
         // synth

h2/src/test/org/h2/test/TestBase.java

@@ -60,6 +60,17 @@ public abstract class TestBase {
         config.beforeTest();
     }
 
+    /**
+     * Initialize the test configuration using the default settings.
+     * 
+     * @return itself
+     */
+    public TestBase init() throws Exception {
+        baseDir = getTestDir("");
+        this.config = new TestAll();
+        return this;
+    }
+
     /**
      * Initialize the test configuration.
      * 
@@ -483,11 +494,11 @@ public abstract class TestBase {
             }
             int al = expected.length();
             int bl = actual.length();
-            if (al > 400) {
-                expected = expected.substring(0, 400);
+            if (al > 4000) {
+                expected = expected.substring(0, 4000);
             }
-            if (bl > 400) {
-                actual = actual.substring(0, 400);
+            if (bl > 4000) {
+                actual = actual.substring(0, 4000);
             }
             fail("Expected: " + expected + " (" + al + ") actual: " + actual + " (" + bl + ")");
         }

h2/src/test/org/h2/test/rowlock/TestRowLocks.java

@@ -18,8 +18,12 @@ import org.h2.test.TestBase;
  */
 public class TestRowLocks extends TestBase {
 
+    Statement s1, s2;
     private Connection c1, c2;
-    private Statement s1, s2;
+    
+    public static void main(String[] a) throws Exception {
+        new TestRowLocks().init().test();
+    }
 
     public void test() throws Exception {
         testSetMode();
@@ -30,10 +34,10 @@ public class TestRowLocks extends TestBase {
         deleteDb("rowLocks");
         c1 = getConnection("rowLocks");
         Statement stat = c1.createStatement();
-        stat.execute("SET LOCK_MODE 4");
+        stat.execute("SET LOCK_MODE 2");
         ResultSet rs = stat.executeQuery("call lock_mode()");
         rs.next();
-        assertEquals("4", rs.getString(1));
+        assertEquals("2", rs.getString(1));
         c1.close();
     }
 
@@ -41,40 +45,57 @@ public class TestRowLocks extends TestBase {
         deleteDb("rowLocks");
         c1 = getConnection("rowLocks;MVCC=TRUE");
         s1 = c1.createStatement();
-        s1.execute("SET LOCK_MODE 4");
+        s1.execute("SET LOCK_TIMEOUT 10000");
         s1.execute("CREATE TABLE TEST AS SELECT X ID, 'Hello' NAME FROM SYSTEM_RANGE(1, 3)");
         c1.commit();
         c1.setAutoCommit(false);
         s1.execute("UPDATE TEST SET NAME='Hallo' WHERE ID=1");
+        
         c2 = getConnection("rowLocks");
         c2.setAutoCommit(false);
         s2 = c2.createStatement();
 
-        ResultSet rs = s1.executeQuery("SELECT NAME FROM TEST WHERE ID=1");
-        rs.next();
-        assertEquals("Hallo", rs.getString(1));
-
-        rs = s2.executeQuery("SELECT NAME FROM TEST WHERE ID=1");
-        rs.next();
-        assertEquals("Hello", rs.getString(1));
+        assertEquals("Hallo", getSingleValue(s1, "SELECT NAME FROM TEST WHERE ID=1"));
+        assertEquals("Hello", getSingleValue(s2, "SELECT NAME FROM TEST WHERE ID=1"));
 
         s2.execute("UPDATE TEST SET NAME='Hallo' WHERE ID=2");
         try {
-            s2.executeUpdate("UPDATE TEST SET NAME='Hallo2' WHERE ID=1");
+            s2.executeUpdate("UPDATE TEST SET NAME='Hi' WHERE ID=1");
             fail();
         } catch (SQLException e) {
             assertKnownException(e);
         }
         c1.commit();
         c2.commit();
-        rs = s1.executeQuery("SELECT NAME FROM TEST WHERE ID=1");
-        rs.next();
-        assertEquals("Hallo", rs.getString(1));
-        rs = s2.executeQuery("SELECT NAME FROM TEST WHERE ID=1");
-        rs.next();
-        assertEquals("Hallo", rs.getString(1));
+        
+        assertEquals("Hallo", getSingleValue(s1, "SELECT NAME FROM TEST WHERE ID=1"));
+        assertEquals("Hallo", getSingleValue(s2, "SELECT NAME FROM TEST WHERE ID=1"));
+        
+        s2.execute("UPDATE TEST SET NAME='H1' WHERE ID=1");
+        Thread thread = new Thread() {
+            public void run() {
+                try {
+                    s1.execute("UPDATE TEST SET NAME='H2' WHERE ID=1");
+                } catch (SQLException e) {
+                    e.printStackTrace();
+                }
+            }
+        };
+        thread.start();
+        Thread.sleep(100);
+        c2.commit();
+        thread.join();
+        c1.commit();
+        assertEquals("H2", getSingleValue(s1, "SELECT NAME FROM TEST WHERE ID=1"));
+        assertEquals("H2", getSingleValue(s2, "SELECT NAME FROM TEST WHERE ID=1"));
+        
         c1.close();
         c2.close();
     }
 
+    private String getSingleValue(Statement stat, String sql) throws Exception {
+        ResultSet rs = stat.executeQuery(sql);
+        return rs.next() ? rs.getString(1) : null;
+    }
+    
 }