private boolean runPolling() {
            try {
                // to make sure that the log file contains up-to-date text,
                // don't do buffering.
                StreamTaskListener listener = new StreamTaskListener(getLogFile());

                try {
                    PrintStream logger = listener.getLogger();
                    long start = System.currentTimeMillis();
                    logger.println("Started on "+ DateFormat.getDateTimeInstance().format(new Date()));
                    boolean result = job.poll(listener).hasChanges();                             <=== check if job duplicated before starting a needless poll (A)
                    logger.println("Done. Took "+ Util.getTimeSpanString(System.currentTimeMillis()-start));                                           
                    if(result.)                                                                                                                        
                        logger.println("Changes found");                                                                                               
                    else                                                          
                        logger.println("No changes");
                    return result;
                } catch (Error e) {
                    e.printStackTrace(listener.error("Failed to record SCM polling for "+job));
                    LOGGER.log(Level.SEVERE,"Failed to record SCM polling for "+job,e);
                    throw e;
                } catch (RuntimeException e) {
                    e.printStackTrace(listener.error("Failed to record SCM polling for "+job));
                    LOGGER.log(Level.SEVERE,"Failed to record SCM polling for "+job,e);
                    throw e;
                } finally {
                    listener.close();
                }
            } catch (IOException e) {
                LOGGER.log(Level.SEVERE,"Failed to record SCM polling for "+job,e);
                return false;
            }
        }

        public void run() {
            String threadName = Thread.currentThread().getName();
            Thread.currentThread().setName("SCM polling for "+job);
            try {
                startTime = System.currentTimeMillis();
                if(runPolling()) {
                    AbstractProject p = job.asProject();
                    String name = " #"+p.getNextBuildNumber();
                    SCMTriggerCause cause;
                    try {
                        cause = new SCMTriggerCause(getLogFile());
                    } catch (IOException e) {
                        LOGGER.log(WARNING, "Failed to parse the polling log",e);
                        cause = new SCMTriggerCause();
                    }
                    if(p.scheduleBuild(p.getQuietPeriod(), cause, additionalActions)) {      <==== checks if a duplicate job is already queued here... it should really check up at A above
                        LOGGER.info("SCM changes detected in "+ job.getName()+". Triggering "+name);
                    } else {
                        LOGGER.info("SCM changes detected in "+ job.getName()+". Job is already in the queue");
                    }
                }
            } finally {
                Thread.currentThread().setName(threadName);
            }
        }