/** {@inheritDoc} */
    @Override
    public Serializable execute() {
      synchronized (mux) {
        execCnt++;
      }

      if (log.isInfoEnabled()) log.info("Executing job: " + jobCtx.getJobId());

      long now = System.currentTimeMillis();

      while (!isCancelled && now < thresholdTime) {
        synchronized (mux) {
          try {
            mux.wait(thresholdTime - now);
          } catch (InterruptedException ignored) {
            // No-op.
          }
        }

        now = System.currentTimeMillis();
      }

      synchronized (mux) {
        return isCancelled ? 1 : 0;
      }
    }
    /** {@inheritDoc} */
    @Override
    public void cancel() {
      synchronized (mux) {
        isCancelled = true;

        cancelCnt++;

        mux.notifyAll();
      }

      log.warning("Job cancelled: " + jobCtx.getJobId());
    }