Multi-threaded kernel bugfixes.

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

@@ -224,7 +224,9 @@ public class Session extends SessionWithState {
     public void removeLocalTempTable(Table table) throws SQLException {
         modificationId++;
         localTempTables.remove(table.getName());
-        table.removeChildrenAndResources(this);
+        synchronized (database) {
+            table.removeChildrenAndResources(this);
+        }
     }
 
     /**
@@ -272,7 +274,9 @@ public class Session extends SessionWithState {
     public void removeLocalTempTableIndex(Index index) throws SQLException {
         if (localTempTableIndexes != null) {
             localTempTableIndexes.remove(index.getName());
-            index.removeChildrenAndResources(this);
+            synchronized (database) {
+                index.removeChildrenAndResources(this);
+            }
         }
     }
 
@@ -328,7 +332,9 @@ public class Session extends SessionWithState {
     public void removeLocalTempTableConstraint(Constraint constraint) throws SQLException {
         if (localTempTableConstraints != null) {
             localTempTableConstraints.remove(constraint.getName());
-            constraint.removeChildrenAndResources(this);
+            synchronized (database) {
+                constraint.removeChildrenAndResources(this);
+            }
         }
     }
 
@@ -647,14 +653,16 @@ public class Session extends SessionWithState {
 
     private void cleanTempTables(boolean closeSession) throws SQLException {
         if (localTempTables != null && localTempTables.size() > 0) {
-            for (Table table : ObjectArray.newInstance(localTempTables.values())) {
-                if (closeSession || table.getOnCommitDrop()) {
-                    modificationId++;
-                    table.setModified();
-                    localTempTables.remove(table.getName());
-                    table.removeChildrenAndResources(this);
-                } else if (table.getOnCommitTruncate()) {
-                    table.truncate(this);
+            synchronized (database) {
+                for (Table table : ObjectArray.newInstance(localTempTables.values())) {
+                    if (closeSession || table.getOnCommitDrop()) {
+                        modificationId++;
+                        table.setModified();
+                        localTempTables.remove(table.getName());
+                        table.removeChildrenAndResources(this);
+                    } else if (table.getOnCommitTruncate()) {
+                        table.truncate(this);
+                    }
                 }
             }
         }

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

@@ -495,7 +495,9 @@ public class Schema extends DbObjectBase {
      */
     public TableData createTable(String tableName, int id, ObjectArray<Column> columns, boolean persistIndexes, boolean persistData, boolean clustered, int headPos, Session session)
             throws SQLException {
-        return new TableData(this, tableName, id, columns, persistIndexes, persistData, clustered, headPos, session);
+        synchronized (database) {
+            return new TableData(this, tableName, id, columns, persistIndexes, persistData, clustered, headPos, session);
+        }
     }
 
     /**
@@ -515,7 +517,9 @@ public class Schema extends DbObjectBase {
      */
     public TableLink createTableLink(int id, String tableName, String driver, String url, String user, String password,
             String originalSchema, String originalTable, boolean emitUpdates, boolean force) throws SQLException {
-        return new TableLink(this, id, tableName, driver, url, user, password, originalSchema, originalTable, emitUpdates, force);
+        synchronized (database) {
+            return new TableLink(this, id, tableName, driver, url, user, password, originalSchema, originalTable, emitUpdates, force);
+        }
     }
 
 }

h2/src/main/org/h2/store/DiskFile.java

@@ -682,24 +682,26 @@ public class DiskFile implements CacheWriter {
 
     private void reuseSpace() throws SQLException {
         if (SysProperties.REUSE_SPACE_QUICKLY) {
-            if (potentiallyFreePages.size() >= SysProperties.REUSE_SPACE_AFTER) {
-                Session[] sessions = database.getSessions(true);
-                int oldest = 0;
-                for (int i = 0; i < sessions.length; i++) {
-                    int deleteId = sessions[i].getLastUncommittedDelete();
-                    if (oldest == 0 || (deleteId != 0 && deleteId < oldest)) {
-                        oldest = deleteId;
+            synchronized (potentiallyFreePages) {
+                if (potentiallyFreePages.size() >= SysProperties.REUSE_SPACE_AFTER) {
+                    Session[] sessions = database.getSessions(true);
+                    int oldest = 0;
+                    for (int i = 0; i < sessions.length; i++) {
+                        int deleteId = sessions[i].getLastUncommittedDelete();
+                        if (oldest == 0 || (deleteId != 0 && deleteId < oldest)) {
+                            oldest = deleteId;
+                        }
                     }
-                }
-                for (Iterator<Integer> it = potentiallyFreePages.iterator(); it.hasNext();) {
-                    int p = it.next();
-                    if (oldest == 0) {
-                        if (isPageFree(p)) {
-                            // the page may not be free: the storage
-                            // could have re-used it using the storage local free list
-                            setPageOwner(p, FREE_PAGE);
+                    for (Iterator<Integer> it = potentiallyFreePages.iterator(); it.hasNext();) {
+                        int p = it.next();
+                        if (oldest == 0) {
+                            if (isPageFree(p)) {
+                                // the page may not be free: the storage
+                                // could have re-used it using the storage local free list
+                                setPageOwner(p, FREE_PAGE);
+                            }
+                            it.remove();
                         }
-                        it.remove();
                     }
                 }
             }
@@ -733,7 +735,9 @@ public class DiskFile implements CacheWriter {
             setPageOwner(page, FREE_PAGE);
         } else {
             if (SysProperties.REUSE_SPACE_QUICKLY) {
-                potentiallyFreePages.add(page);
+                synchronized (potentiallyFreePages) {
+                    potentiallyFreePages.add(page);
+                }
             }
         }
     }
@@ -794,7 +798,9 @@ public class DiskFile implements CacheWriter {
         if (storageId >= 0) {
             database.getStorage(storageId, this).addPage(page);
             if (SysProperties.REUSE_SPACE_QUICKLY) {
-                potentiallyFreePages.remove(page);
+                synchronized (potentiallyFreePages) {
+                    potentiallyFreePages.remove(page);
+                }
             }
         } else {
             firstFreePage = Math.min(firstFreePage, page);

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

@@ -38,6 +38,7 @@ import org.h2.test.db.TestMemoryUsage;
 import org.h2.test.db.TestMultiConn;
 import org.h2.test.db.TestMultiDimension;
 import org.h2.test.db.TestMultiThread;
+import org.h2.test.db.TestMultiThreadedKernel;
 import org.h2.test.db.TestOpenClose;
 import org.h2.test.db.TestOptimizations;
 import org.h2.test.db.TestOutOfMemory;
@@ -115,7 +116,6 @@ import org.h2.test.unit.TestFtp;
 import org.h2.test.unit.TestIntArray;
 import org.h2.test.unit.TestIntIntHashMap;
 import org.h2.test.unit.TestMathUtils;
-import org.h2.test.unit.TestMultiThreadedKernel;
 import org.h2.test.unit.TestOverflow;
 import org.h2.test.unit.TestPattern;
 import org.h2.test.unit.TestPgServer;
@@ -295,6 +295,12 @@ java org.h2.test.TestAll timer
 /*
 
 better document that ddl statements commit
+"This command commits an open transaction."
+PostgreSQL compatibility: 2001-02-03 08:20:31+01 (:minutes optional)
+Support Java 6 DatabaseMetaData.getColumns, getProcedures, getProcedureColumns, getTables.
+MySQL compatibility for "show columns from test"
+
+-------------
 
 create a short documentation
 
@@ -478,6 +484,7 @@ kill -9 `jps -l | grep "org.h2.test.TestAll" | cut -d " " -f 1`
         new TestMultiConn().runTest(this);
         new TestMultiDimension().runTest(this);
         new TestMultiThread().runTest(this);
+        new TestMultiThreadedKernel().runTest(this);
         new TestOpenClose().runTest(this);
         new TestOptimizations().runTest(this);
         new TestOutOfMemory().runTest(this);

h2/src/test/org/h2/test/db/TestMultiThreadedKernel.java

+/*
+ * Copyright 2004-2009 H2 Group. Multiple-Licensed under the H2 License,
+ * Version 1.0, and under the Eclipse Public License, Version 1.0
+ * (http://h2database.com/html/license.html).
+ * Initial Developer: H2 Group
+ */
+package org.h2.test.db;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.Statement;
+import org.h2.test.TestBase;
+import org.h2.util.JdbcUtils;
+
+/**
+ * A multi-threaded test case.
+ */
+public class TestMultiThreadedKernel extends TestBase {
+    volatile boolean stop;
+    Exception exception;
+
+    /**
+     * Run just this test.
+     *
+     * @param a ignored
+     */
+    public static void main(String[] a) throws Exception {
+        TestBase.createCaller().init().test();
+    }
+
+    public void test() throws Exception {
+        if (config.mvcc) {
+            return;
+        }
+        deleteDb("multiThreadedKernel");
+        final String url = getURL("multiThreadedKernel;DB_CLOSE_DELAY=-1;MULTI_THREADED=1", true);
+        final String user = getUser(), password = getPassword();
+        int len = 3;
+        Thread[] threads = new Thread[len];
+        for (int i = 0; i < len; i++) {
+            threads[i] = new Thread(new Runnable() {
+                public void run() {
+                    Connection conn = null;
+                    try {
+                        for (int i = 0; i < 100 && !stop; i++) {
+                            conn = DriverManager.getConnection(url, user, password);
+                            Statement stat = conn.createStatement();
+                            stat.execute("create local temporary table temp(id identity)");
+                            stat.execute("insert into temp values(1)");
+                            conn.close();
+                        }
+                    } catch (Exception e) {
+                        exception = e;
+                    } finally {
+                        JdbcUtils.closeSilently(conn);
+                    }
+                }
+            });
+        }
+        for (int i = 0; i < len; i++) {
+            threads[i].start();
+        }
+        Thread.sleep(1000);
+        stop = true;
+        for (int i = 0; i < len; i++) {
+            threads[i].join();
+        }
+        Connection conn = DriverManager.getConnection(url, user, password);
+        conn.createStatement().execute("shutdown");
+        conn.close();
+        if (exception != null) {
+            throw exception;
+        }
+    }
+
+}