[CONJ-297] Useless memory consumption when using Statement.setQueryTi…

…meout + checkstyle correction

documentation/Changelog.md

@@ -8,6 +8,7 @@
 
 ---
 ## 1.4.5
+* [CONJ-297] Useless memory consumption when using Statement.setQueryTimeout
 * [CONJ-289] PrepareStatement on master reconnection after a failover
 * [CONJ-288] using SHOW VARIABLES to replace SELECT on connection to permit connection on a galera non primary node
 

src/main/java/org/mariadb/jdbc/MariaDbDatabaseMetaData.java

@@ -540,8 +540,8 @@ public ResultSet getTables(String catalog, String schemaPattern, String tableNam
             throws SQLException {
 
         String sql =
-                "SELECT TABLE_SCHEMA TABLE_CAT, NULL  TABLE_SCHEM,  TABLE_NAME, IF(TABLE_TYPE='BASE TABLE', 'TABLE', TABLE_TYPE) as TABLE_TYPE, TABLE_COMMENT REMARKS,"
-                        + " NULL TYPE_CAT, NULL TYPE_SCHEM, NULL TYPE_NAME, NULL SELF_REFERENCING_COL_NAME, "
+                "SELECT TABLE_SCHEMA TABLE_CAT, NULL  TABLE_SCHEM,  TABLE_NAME, IF(TABLE_TYPE='BASE TABLE', 'TABLE', TABLE_TYPE) as TABLE_TYPE,"
+                        + " TABLE_COMMENT REMARKS, NULL TYPE_CAT, NULL TYPE_SCHEM, NULL TYPE_NAME, NULL SELF_REFERENCING_COL_NAME, "
                         + " NULL REF_GENERATION"
                         + " FROM INFORMATION_SCHEMA.TABLES "
                         + " WHERE "

src/main/java/org/mariadb/jdbc/MariaDbStatement.java

@@ -49,33 +49,27 @@ WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWIS
 
 package org.mariadb.jdbc;
 
-import org.mariadb.jdbc.internal.packet.dao.parameters.ParameterHolder;
-import org.mariadb.jdbc.internal.queryresults.*;
 import org.mariadb.jdbc.internal.protocol.Protocol;
 import org.mariadb.jdbc.internal.queryresults.ExecutionResult;
 import org.mariadb.jdbc.internal.queryresults.MultiIntExecutionResult;
 import org.mariadb.jdbc.internal.queryresults.SingleExecutionResult;
 import org.mariadb.jdbc.internal.queryresults.resultset.MariaSelectResultSet;
 import org.mariadb.jdbc.internal.util.ExceptionMapper;
 import org.mariadb.jdbc.internal.util.dao.QueryException;
-import org.mariadb.jdbc.internal.util.scheduler.DynamicSizedSchedulerInterface;
 import org.mariadb.jdbc.internal.util.scheduler.SchedulerServiceProviderHolder;
 
-import org.mariadb.jdbc.internal.protocol.Protocol;
-
 import java.io.IOException;
 import java.io.InputStream;
 import java.sql.*;
 import java.util.*;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
+import java.util.concurrent.*;
 import java.util.concurrent.locks.ReentrantLock;
 
 
 public class MariaDbStatement implements Statement, Cloneable {
-    private static final DynamicSizedSchedulerInterface timeoutScheduler =
-            SchedulerServiceProviderHolder.getScheduler(0);
+    //timeout scheduler
+    private static volatile ScheduledThreadPoolExecutor timeoutScheduler = null;
+
     /**
      * the protocol used to talk to the server.
      */
@@ -161,9 +155,16 @@ public Protocol getProtocol() {
     protected void setTimerTask() {
         assert (timerTaskFuture == null);
 
-        // because canceling needs to establish a new connection, we want to ensure that this
-        // possible blocking call can be run in parallel if multiple queries need to timeout
-        timerTaskFuture = timeoutScheduler.addThreadAndSchedule(new Runnable() {
+        if (timeoutScheduler == null) {
+            //Scheduler initialisation
+            synchronized (connection) {
+                if (timeoutScheduler == null) {
+                    timeoutScheduler = SchedulerServiceProviderHolder.getSchedulerProvider().getTimeoutScheduler();
+                }
+            }
+        }
+
+        timerTaskFuture = timeoutScheduler.schedule(new Runnable() {
             @Override
             public void run() {
                 try {

src/main/java/org/mariadb/jdbc/internal/packet/send/SendGssApiAuthPacket.java

@@ -98,7 +98,6 @@ public void send(OutputStream os) throws IOException, QueryException {
                         "Krb5ConnectorContext {\n"
                                 + "com.sun.security.auth.module.Krb5LoginModule required "
                                 + "useTicketCache=true "
-                                + "debug=true "
                                 + "renewTGT=true "
                                 + "doNotPrompt=true; };"
                 ));
@@ -159,14 +158,14 @@ public Void run() throws Exception {
                     };
                     Subject.doAs(mySubject, action);
                 } catch (PrivilegedActionException exception) {
-                    throw new QueryException("GSS-API authentication exception", 0, "28000", exception);
+                    throw new QueryException("GSS-API authentication exception", 1045, "28000", exception);
                 }
             } else {
-                throw new QueryException("GSS-API authentication exception : no credential cache not found.", 0, "28000");
+                throw new QueryException("GSS-API authentication exception : no credential cache not found.", 1045, "28000");
             }
 
         } catch (LoginException le) {
-            throw new QueryException("GSS-API authentication exception", 0, "28000", le);
+            throw new QueryException("GSS-API authentication exception", 1045, "28000", le);
         }
 
     }

src/main/java/org/mariadb/jdbc/internal/util/scheduler/DynamicSizedSchedulerImpl.java

@@ -49,10 +49,7 @@ WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWIS
 
 package org.mariadb.jdbc.internal.util.scheduler;
 
-import java.util.concurrent.Future;
-import java.util.concurrent.FutureTask;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
-import java.util.concurrent.TimeUnit;
 
 public class DynamicSizedSchedulerImpl extends ScheduledThreadPoolExecutor implements DynamicSizedSchedulerInterface {
     /**
@@ -70,44 +67,4 @@ public void setPoolSize(int newSize) {
         }
     }
 
-    @Override
-    public void adjustPoolSize(int delta) {
-        // locked to avoid check then act race condition
-        synchronized (this) {
-            super.setCorePoolSize(Math.max(0, super.getCorePoolSize() + delta));
-        }
-    }
-
-    @Override
-    public Future<?> addThreadAndExecute(final Runnable task) {
-        return addThreadAndSchedule(task, 0, TimeUnit.MILLISECONDS);
-    }
-
-    @Override
-    public Future<?> addThreadAndSchedule(final Runnable task, long delay, TimeUnit unit) {
-        adjustPoolSize(1);
-
-        FutureTask<?> result = new PoolSizeDecreaseFuture(task);
-        if (delay == 0) {
-            // execute is slightly better if we can, as it avoids wrapping the future in another future
-            super.execute(result);
-        } else {
-            super.schedule(result, delay, unit);
-            // can not return future from schedule above
-            // we must return our decreasing future to handle Future.cancel case
-        }
-        return result;
-    }
-
-    private class PoolSizeDecreaseFuture extends FutureTask<Object> {
-        public PoolSizeDecreaseFuture(Runnable runnable) {
-            super(runnable, null);
-        }
-
-        @Override
-        protected void done() {
-            // invoked when task is complete or canceled
-            adjustPoolSize(-1);
-        }
-    }
 }

src/main/java/org/mariadb/jdbc/internal/util/scheduler/DynamicSizedSchedulerInterface.java

@@ -49,9 +49,7 @@ WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWIS
 
 package org.mariadb.jdbc.internal.util.scheduler;
 
-import java.util.concurrent.Future;
 import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
 
 public interface DynamicSizedSchedulerInterface extends ScheduledExecutorService {
     /**
@@ -60,34 +58,5 @@ public interface DynamicSizedSchedulerInterface extends ScheduledExecutorService
      * @param newSize New pool size that is superior to 0
      */
     public void setPoolSize(int newSize);
-
-    /**
-     * Adjusts the pool size by a given delta.  This should atomically change the pool size in a 
-     * thread safe way.
-     * 
-     * @param delta A positive or negative number to adjust the pool size by.
-     */
-    public void adjustPoolSize(int delta);
-
-    /**
-     * Used when you want to ensure an extra thread is available to execute task.  This will adjust 
-     * the pool size so that a thread can be created (if necessary), and then execute the task.  
-     * Once the task completes the pool size will be adjusted back down.
-     * 
-     * @param task Task to be executed
-     * @return Future which represents task execution
-     */
-    public Future<?> addThreadAndExecute(Runnable task);
 
-    /**
-     * Used when you want to ensure an extra thread is available for scheduled task.  This will 
-     * adjust the pool size so that a thread can be created (if necessary), and then execute the 
-     * task.  Once the task completes the pool size will be adjusted back down.
-     * 
-     * @param task Task to be executed
-     * @param delay delay before execution
-     * @param unit unit of delay
-     * @return Future which represents task execution
-     */
-    public Future<?> addThreadAndSchedule(Runnable task, long delay, TimeUnit unit);
 }

src/main/java/org/mariadb/jdbc/internal/util/scheduler/SchedulerServiceProviderHolder.java

@@ -70,6 +70,13 @@ public DynamicSizedSchedulerInterface getScheduler(int minimumThreads) {
         public ScheduledThreadPoolExecutor getFixedSizeScheduler(int minimumThreads) {
             return new FixedSizedSchedulerImpl(minimumThreads);
         }
+
+        @Override
+        public ScheduledThreadPoolExecutor getTimeoutScheduler() {
+            ScheduledThreadPoolExecutor timeoutScheduler = new ScheduledThreadPoolExecutor(1, new MariaDbThreadFactory());
+            timeoutScheduler.setRemoveOnCancelPolicy(true);
+            return timeoutScheduler;
+        }
     };
 
     private static volatile SchedulerProvider currentProvider = null;
@@ -135,6 +142,17 @@ public interface SchedulerProvider {
         public DynamicSizedSchedulerInterface getScheduler(int minimumThreads);
 
         public ScheduledExecutorService getFixedSizeScheduler(int minimumThreads);
+
+        /**
+         * Default Timeout scheduler.
+         *
+         * This is a one Thread fixed sized scheduler.
+         * This specific scheduler is using java 1.7 RemoveOnCancelPolicy, so
+         * the task are removed from queue permitting to avoid memory consumption [CONJ-297]
+         *
+         * @return A new scheduler that is ready to accept tasks
+         */
+        public ScheduledThreadPoolExecutor getTimeoutScheduler();
     }
 
 

src/test/java/org/mariadb/jdbc/DatabaseMetadataTest.java

@@ -364,7 +364,8 @@ public void testGetTables3() throws SQLException {
         assertEquals("table_type_test", tableName);
 
         String tableType = tableSet.getString("TABLE_TYPE");
-        assertEquals("TABLE", tableType);	// see for possible values https://docs.oracle.com/javase/7/docs/api/java/sql/DatabaseMetaData.html#getTableTypes%28%29
+        assertEquals("TABLE", tableType);
+        // see for possible values https://docs.oracle.com/javase/7/docs/api/java/sql/DatabaseMetaData.html#getTableTypes%28%29
     }
 
     @Test

src/test/java/org/mariadb/jdbc/internal/util/SchedulerServiceProviderHolderTest.java

@@ -73,6 +73,11 @@ public DynamicSizedSchedulerInterface getScheduler(int minimumThreads) {
             public ScheduledThreadPoolExecutor getFixedSizeScheduler(int minimumThreads) {
                 throw new UnsupportedOperationException();
             }
+
+            @Override
+            public ScheduledThreadPoolExecutor getTimeoutScheduler() {
+                throw new UnsupportedOperationException();
+            }
         };
 
         SchedulerServiceProviderHolder.setSchedulerProvider(emptyProvider);