code: protected void subAppend(final LoggingEvent event) {
          // The rollover check must precede actual writing. This is the
          // only correct behavior for time driven triggers.
          AccessController.doPrivileged(new PrivilegedAction<Void>() {
              @Override
              public Void run() {
                  if (triggeringPolicy.isTriggeringEvent(RollingFileAppender.this, event, getFile(), getFileLength())) {
                      //
                      //   wrap rollover request in try block since
                      //    rollover may fail in case read access to directory
                      //    is not provided.  However appender should still be in good
                      //     condition and the append should still happen.
                      try {
                          rollover();
                      } catch (Exception ex) {
                          LogLog.warn("Exception during rollover attempt.", ex);
                      }
                  }
                  return null;
              }
          });
          
          super.subAppend(event);
      }
docs: {@inheritDoc}