Fix thread leak when calling createDynamicSession() multiple times

quickfixj-core/src/main/java/quickfix/mina/SessionConnector.java

@@ -311,6 +311,10 @@ private String getLogSuffix(SessionID sessionID, IoSession protocolSession) {
     }
 
     protected void startSessionTimer() {
+        // Check if a session timer is already running to avoid creating multiple timers
+        if (checkSessionTimerRunning()) {
+            return;
+        }
         Runnable timerTask = new SessionTimerTask();
         if (shortLivedExecutor != null) {
             timerTask = new DelegatingTask(timerTask, shortLivedExecutor);

quickfixj-core/src/test/java/quickfix/mina/initiator/DynamicSessionThreadLeakTest.java

@@ -0,0 +1,171 @@
+/*******************************************************************************
+ * Copyright (c) quickfixengine.org  All rights reserved.
+ *
+ * This file is part of the QuickFIX FIX Engine
+ *
+ * This file may be distributed under the terms of the quickfixengine.org
+ * license as defined by quickfixengine.org and appearing in the file
+ * LICENSE included in the packaging of this file.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING
+ * THE WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE.
+ *
+ * See http://www.quickfixengine.org/LICENSE for licensing information.
+ *
+ * Contact ask@quickfixengine.org if any conditions of this licensing
+ * are not clear to you.
+ ******************************************************************************/
+
+package quickfix.mina.initiator;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import quickfix.*;
+import quickfix.mina.EventHandlingStrategy;
+import quickfix.mina.SessionConnector;
+
+import java.lang.reflect.Field;
+import java.util.HashMap;
+import java.util.concurrent.ScheduledFuture;
+
+import static org.junit.Assert.*;
+
+/**
+ * Test for verifying that calling createDynamicSession multiple times does not
+ * create a thread leak by creating multiple session timers.
+ */
+public class DynamicSessionThreadLeakTest {
+
+    private TestAbstractSocketInitiator initiator;
+    private SessionSettings settings;
+
+    @Before
+    public void setUp() throws Exception {
+        SystemTime.setTimeSource(null);
+
+        // Set up minimal session settings
+        settings = new SessionSettings();
+        settings.setString(Session.SETTING_USE_DATA_DICTIONARY, "N");
+        settings.setString(Session.SETTING_START_TIME, "00:00:00");
+        settings.setString(Session.SETTING_END_TIME, "00:00:00");
+        settings.setLong(Session.SETTING_HEARTBTINT, 100L);
+        settings.setString(SocketInitiator.SETTING_SOCKET_CONNECT_HOST, "127.0.0.1");
+        settings.setString(SocketInitiator.SETTING_SOCKET_CONNECT_PORT, "54321");
+        settings.setString(SessionFactory.SETTING_CONNECTION_TYPE, SessionFactory.INITIATOR_CONNECTION_TYPE);
+
+        DefaultSessionFactory sessionFactory = new DefaultSessionFactory(
+                new UnitTestApplication(),
+                new MemoryStoreFactory(),
+                new SLF4JLogFactory(new SessionSettings()));
+
+        initiator = new TestAbstractSocketInitiator(settings, sessionFactory);
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        if (initiator != null) {
+            initiator.stop(true);
+        }
+    }
+
+    /**
+     * Test that multiple calls to createDynamicSession do not create multiple session timers.
+     * Only one session timer should be running at a time.
+     */
+    @Test
+    public void testMultipleCreateDynamicSessionDoesNotLeakThreads() throws Exception {
+        SessionID sessionID1 = new SessionID(FixVersions.BEGINSTRING_FIX42, "SENDER1", "TARGET1");
+        SessionID sessionID2 = new SessionID(FixVersions.BEGINSTRING_FIX42, "SENDER2", "TARGET2");
+        SessionID sessionID3 = new SessionID(FixVersions.BEGINSTRING_FIX42, "SENDER3", "TARGET3");
+
+        // Create first dynamic session
+        initiator.createDynamicSession(sessionID1);
+        assertTrue("Session timer should be running after first createDynamicSession", 
+                   initiator.isSessionTimerRunning());
+        ScheduledFuture<?> firstTimer = initiator.getSessionTimerFuture();
+        assertNotNull("Session timer future should not be null", firstTimer);
+        assertFalse("First timer should not be cancelled", firstTimer.isCancelled());
+
+        // Create second dynamic session
+        initiator.createDynamicSession(sessionID2);
+        assertTrue("Session timer should still be running after second createDynamicSession", 
+                   initiator.isSessionTimerRunning());
+        ScheduledFuture<?> secondTimer = initiator.getSessionTimerFuture();
+        assertNotNull("Session timer future should not be null", secondTimer);
+
+        // The key assertion: The timer should be the same instance, not a new one
+        assertSame("Session timer should be reused, not recreated", firstTimer, secondTimer);
+        assertFalse("First timer should still not be cancelled", firstTimer.isCancelled());
+
+        // Create third dynamic session
+        initiator.createDynamicSession(sessionID3);
+        assertTrue("Session timer should still be running after third createDynamicSession", 
+                   initiator.isSessionTimerRunning());
+        ScheduledFuture<?> thirdTimer = initiator.getSessionTimerFuture();
+        assertNotNull("Session timer future should not be null", thirdTimer);
+
+        // Verify it's still the same timer
+        assertSame("Session timer should be reused, not recreated", firstTimer, thirdTimer);
+        assertFalse("First timer should still not be cancelled", firstTimer.isCancelled());
+
+        // Verify that all three sessions were created
+        assertEquals("Three sessions should be created", 3, initiator.getManagedSessions().size());
+
+        // Stop the initiator and verify the timer is cancelled
+        initiator.stop(true);
+        assertTrue("Timer should be cancelled after stop", firstTimer.isCancelled());
+    }
+
+    /**
+     * Test implementation of AbstractSocketInitiator for testing purposes.
+     */
+    private static class TestAbstractSocketInitiator extends AbstractSocketInitiator {
+
+        public TestAbstractSocketInitiator(SessionSettings settings, SessionFactory sessionFactory) throws ConfigError {
+            super(settings, sessionFactory);
+        }
+
+        @Override
+        public void start() throws ConfigError, RuntimeError {
+            // No-op for testing
+        }
+
+        @Override
+        public void stop() {
+            clearConnectorSessions();
+            stopInitiators();
+        }
+
+        @Override
+        public void stop(boolean force) {
+            clearConnectorSessions();
+            stopInitiators();
+        }
+
+        @Override
+        protected EventHandlingStrategy getEventHandlingStrategy() {
+            return null;
+        }
+
+        /**
+         * Expose the session timer running status for testing using reflection.
+         */
+        public boolean isSessionTimerRunning() throws Exception {
+            Field field = SessionConnector.class.getDeclaredField("sessionTimerFuture");
+            field.setAccessible(true);
+            ScheduledFuture<?> future = (ScheduledFuture<?>) field.get(this);
+            return future != null && !future.isDone();
+        }
+
+        /**
+         * Expose the session timer future for testing using reflection.
+         */
+        public ScheduledFuture<?> getSessionTimerFuture() throws Exception {
+            Field field = SessionConnector.class.getDeclaredField("sessionTimerFuture");
+            field.setAccessible(true);
+            return (ScheduledFuture<?>) field.get(this);
+        }
+    }
+}