output: #fixed code
                                  @Override
      public void close() throws SQLException {
          if (closed) {
              return;
          }
          synchronized (this) {
              if (closed) {
                  return;
              }
              closed = true;
              SQLException sqlE = null;
              try {
                  // Attempt to return any unused sequences.
                  if (connection != null) returnAllSequences(this.sequenceMap);
              } catch (SQLException e) {
                  sqlE = e;
              } finally {
                  try {
                      // Clear any client-side caches.  
                      statsManager.clearStats();
                  } catch (SQLException e) {
                      if (sqlE == null) {
                          sqlE = e;
                      } else {
                          sqlE.setNextException(e);
                      }
                  } finally {
                      try {
                          childServices.clear();
                          latestMetaData = null;
                          if (connection != null) connection.close();
                      } catch (IOException e) {
                          if (sqlE == null) {
                              sqlE = ServerUtil.parseServerException(e);
                          } else {
                              sqlE.setNextException(ServerUtil.parseServerException(e));
                          }
                      } finally {
                          try {
                              super.close();
                          } catch (SQLException e) {
                              if (sqlE == null) {
                                  sqlE = e;
                              } else {
                                  sqlE.setNextException(e);
                              }
                          } finally {
                              if (sqlE != null) {
                                  throw sqlE;
                              }
                          }
                      }
                  }
              }
          }
      }
input: #vulnerable code 
                                  @Override
      public void close() throws SQLException {
          SQLException sqlE = null;
          try {
              // Attempt to return any unused sequences.
              returnAllSequences(this.sequenceMap);
          } catch (SQLException e) {
              sqlE = e;
          } finally {
              try {
                  // Clear any client-side caches.  
                  statsManager.clearStats();
              } catch (SQLException e) {
                  if (sqlE == null) {
                      sqlE = e;
                  } else {
                      sqlE.setNextException(e);
                  }
              } finally {
                  try {
                      childServices.clear();
                      latestMetaData = null;
                      connection.close();
                  } catch (IOException e) {
                      if (sqlE == null) {
                          sqlE = ServerUtil.parseServerException(e);
                      } else {
                          sqlE.setNextException(ServerUtil.parseServerException(e));
                      }
                  } finally {
                      try {
                          super.close();
                      } catch (SQLException e) {
                          if (sqlE == null) {
                              sqlE = e;
                          } else {
                              sqlE.setNextException(e);
                          }
                      } finally {
                          if (sqlE != null) {
                              throw sqlE;
                          }
                      }
                  }
              }
          }
      } 
                              #location 6 
                              #vulnerability type THREAD_SAFETY_VIOLATION