Serialized access mode (server-less multi-connection mode): sequences did not work as expected.

h2/src/docsrc/html/changelog.html

@@ -18,7 +18,9 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>Page store: new databases can not be opened with older versions.
+<ul><li>Serialized access mode (server-less multi-connection mode): sequences did not work as expected
+    (there were gaps in generated values when using multiple connections).
+</li><li>Page store: new databases can not be opened with older versions.
 </li><li>Page store: adding data to new database is now faster.
 </li><li>File system: getting the file name from a path is now faster. This should
     speed up BLOB and CLOB access.

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

@@ -2412,6 +2412,7 @@ public class Database implements DataHandler {
             synchronized (this) {
                 getTrace().debug("checkpoint start");
                 flushIndexes(0);
+                flushSequences();
                 checkpoint();
                 reconnectModified(false);
                 getTrace().debug("checkpoint end");
@@ -2455,6 +2456,13 @@ public class Database implements DataHandler {
         }
     }
 
+    private void flushSequences() throws SQLException {
+        for (SchemaObject obj : getAllSchemaObjects(DbObject.SEQUENCE)) {
+            Sequence sequence = (Sequence) obj;
+            sequence.flushWithoutMargin();
+        }
+    }
+
     /**
      * Flush all changes and open a new log file.
      */
@@ -2463,7 +2471,6 @@ public class Database implements DataHandler {
             if (pageStore != null) {
                 pageStore.checkpoint();
             }
-            LogSystem log = getLog();
             if (log != null) {
                 log.checkpoint();
             }

h2/src/main/org/h2/schema/Sequence.java

@@ -99,6 +99,16 @@ public class Sequence extends SchemaObjectBase {
         return v;
     }
 
+    /**
+     * Flush the current value to disk.
+     */
+    public void flushWithoutMargin() throws SQLException {
+        if (valueWithMargin != value) {
+            valueWithMargin = value;
+            flush(null);
+        }
+    }
+
     /**
      * Flush the current value, including the margin, to disk.
      *
@@ -133,8 +143,7 @@ public class Sequence extends SchemaObjectBase {
      * Flush the current value to disk and close this object.
      */
     public void close() throws SQLException {
-        valueWithMargin = value;
-        flush(null);
+        flushWithoutMargin();
     }
 
     public int getType() {

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

@@ -299,6 +299,9 @@ java org.h2.test.TestAll timer
 
 /*
 
+power failure test: larger binaries and additional indexes
+(with many columns).
+
 increment storage read version
 
 update copyright to 2010

h2/src/test/org/h2/test/unit/TestFileLockSerialized.java

@@ -36,6 +36,8 @@ public class TestFileLockSerialized extends TestBase {
     }
 
     public void test() throws Exception {
+        println("testSequenceFlush");
+        testSequenceFlush();
         println("testLeftLogFiles");
         testLeftLogFiles();
         println("testWrongDatabaseInstanceOnReconnect");
@@ -66,6 +68,25 @@ public class TestFileLockSerialized extends TestBase {
         testConcurrentReadWrite();
     }
 
+    private void testSequenceFlush() throws Exception {
+        deleteDb("fileLockSerialized");
+        String url = "jdbc:h2:" + baseDir + "/fileLockSerialized;FILE_LOCK=SERIALIZED;OPEN_NEW=TRUE";
+        ResultSet rs;
+        Connection conn1 = DriverManager.getConnection(url);
+        Statement stat1 = conn1.createStatement();
+        stat1.execute("create sequence seq");
+        rs = stat1.executeQuery("call seq.nextval");
+        rs.next();
+        assertEquals(1, rs.getInt(1));
+        Connection conn2 = DriverManager.getConnection(url);
+        Statement stat2 = conn2.createStatement();
+        rs = stat2.executeQuery("call seq.nextval");
+        rs.next();
+        assertEquals(2, rs.getInt(1));
+        conn1.close();
+        conn2.close();
+    }
+
     private void testThreeMostlyReaders(final boolean write) throws Exception {
         boolean longRun = false;
         deleteDb("fileLockSerialized");