output: #fixed code
                                  public void connect() throws IOException {
          if (!connectLock.tryLock()) {
              throw new IllegalStateException("BinaryLogClient is already connected");
          }
          boolean notifyWhenDisconnected = false;
          try {
              try {
                  channel = openChannel();
                  GreetingPacket greetingPacket = receiveGreeting();
                  authenticate(greetingPacket);
                  connectionId = greetingPacket.getThreadId();
                  if (binlogFilename == null) {
                      fetchBinlogFilenameAndPosition();
                  }
                  if (binlogPosition < 4) {
                      if (logger.isLoggable(Level.WARNING)) {
                          logger.warning("Binary log position adjusted from " + binlogPosition + " to " + 4);
                      }
                      binlogPosition = 4;
                  }
                  ChecksumType checksumType = fetchBinlogChecksum();
                  if (checksumType != ChecksumType.NONE) {
                      confirmSupportOfChecksum(checksumType);
                  }
                  requestBinaryLogStream();
              } catch (IOException e) {
                  disconnectChannel();
                  throw e;
              }
              connected = true;
              notifyWhenDisconnected = true;
              if (logger.isLoggable(Level.INFO)) {
                  String position;
                  synchronized (gtidSetAccessLock) {
                      position = gtidSet != null ? gtidSet.toString() : binlogFilename + "/" + binlogPosition;
                  }
                  logger.info("Connected to " + hostname + ":" + port + " at " + position +
                      " (" + (blocking ? "sid:" + serverId + ", " : "") + "cid:" + connectionId + ")");
              }
              synchronized (lifecycleListeners) {
                  for (LifecycleListener lifecycleListener : lifecycleListeners) {
                      lifecycleListener.onConnect(this);
                  }
              }
              if (keepAlive && !isKeepAliveThreadRunning()) {
                  spawnKeepAliveThread();
              }
              ensureEventDataDeserializer(EventType.ROTATE, RotateEventDataDeserializer.class);
              synchronized (gtidSetAccessLock) {
                  if (gtidSet != null) {
                      ensureEventDataDeserializer(EventType.GTID, GtidEventDataDeserializer.class);
                  }
              }
              listenForEventPackets();
          } finally {
              connectLock.unlock();
              if (notifyWhenDisconnected) {
                  synchronized (lifecycleListeners) {
                      for (LifecycleListener lifecycleListener : lifecycleListeners) {
                          lifecycleListener.onDisconnect(this);
                      }
                  }
              }
          }
      }
input: #vulnerable code 
                                  public void connect() throws IOException {
          if (connected) {
              throw new IllegalStateException("BinaryLogClient is already connected");
          }
          GreetingPacket greetingPacket;
          try {
              try {
                  Socket socket = socketFactory != null ? socketFactory.createSocket() : new Socket();
                  socket.connect(new InetSocketAddress(hostname, port));
                  channel = new PacketChannel(socket);
                  if (channel.getInputStream().peek() == -1) {
                      throw new EOFException();
                  }
              } catch (IOException e) {
                  throw new IOException("Failed to connect to MySQL on " + hostname + ":" + port +
                      ". Please make sure it's running.", e);
              }
              greetingPacket = receiveGreeting();
              authenticate(greetingPacket);
              if (binlogFilename == null) {
                  fetchBinlogFilenameAndPosition();
              }
              if (binlogPosition < 4) {
                  if (logger.isLoggable(Level.WARNING)) {
                      logger.warning("Binary log position adjusted from " + binlogPosition + " to " + 4);
                  }
                  binlogPosition = 4;
              }
              ChecksumType checksumType = fetchBinlogChecksum();
              if (checksumType != ChecksumType.NONE) {
                  confirmSupportOfChecksum(checksumType);
              }
              requestBinaryLogStream();
          } catch (IOException e) {
              if (channel != null && channel.isOpen()) {
                  channel.close();
              }
              throw e;
          }
          connected = true;
          connectionId = greetingPacket.getThreadId();
          if (logger.isLoggable(Level.INFO)) {
              String position;
              synchronized (gtidSetAccessLock) {
                  position = gtidSet != null ? gtidSet.toString() : binlogFilename + "/" + binlogPosition;
              }
              logger.info("Connected to " + hostname + ":" + port + " at " + position +
                  " (" + (blocking ? "sid:" + serverId + ", " : "") + "cid:" + connectionId + ")");
          }
          synchronized (lifecycleListeners) {
              for (LifecycleListener lifecycleListener : lifecycleListeners) {
                  lifecycleListener.onConnect(this);
              }
          }
          if (keepAlive && !isKeepAliveThreadRunning()) {
              spawnKeepAliveThread();
          }
          ensureEventDataDeserializer(EventType.ROTATE, RotateEventDataDeserializer.class);
          synchronized (gtidSetAccessLock) {
              if (gtidSet != null) {
                  ensureEventDataDeserializer(EventType.GTID, GtidEventDataDeserializer.class);
              }
          }
          listenForEventPackets();
      } 
                              #location 18 
                              #vulnerability type THREAD_SAFETY_VIOLATION