/**
   * Gets job priority. At first tries to get from job context. If job context has no priority, then
   * tries to get from task session. If task session has no priority default one will be used.
   *
   * @param ctx Collision job context.
   * @return Job priority.
   */
  private int getJobPriority(GridCollisionJobContext ctx) {
    assert ctx != null;

    Integer p = null;

    GridJobContext jctx = ctx.getJobContext();

    try {
      p = (Integer) jctx.getAttribute(jobAttrKey);
    } catch (ClassCastException e) {
      LT.error(
          log,
          e,
          "Type of job context priority attribute '"
              + jobAttrKey
              + "' is not java.lang.Integer [type="
              + jctx.getAttribute(jobAttrKey).getClass()
              + ']');
    }

    if (p == null) {
      GridTaskSession ses = ctx.getTaskSession();

      try {
        p = (Integer) ses.getAttribute(taskAttrKey);
      } catch (ClassCastException e) {
        LT.error(
            log,
            e,
            "Type of task session priority attribute '"
                + taskAttrKey
                + "' is not java.lang.Integer [type="
                + ses.getAttribute(taskAttrKey).getClass()
                + ']');
      }

      if (p == null) {
        if (log.isDebugEnabled()) {
          log.debug(
              "Failed get priority from job context attribute '"
                  + jobAttrKey
                  + "' and task session attribute '"
                  + taskAttrKey
                  + "' (will use default priority): "
                  + dfltPriority);
        }

        p = dfltPriority;
      }
    }

    assert p != null;

    return p;
  }
  /**
   * Increases priority if job has bumped down.
   *
   * @param waitJobs Ordered collection of collision contexts for jobs that are currently waiting
   *     for execution.
   * @param passiveJobs Reordered collection of collision contexts for waiting jobs.
   */
  private void bumpPriority(
      Collection<GridCollisionJobContext> waitJobs, List<GridCollisionJobContext> passiveJobs) {
    assert waitJobs != null;
    assert passiveJobs != null;
    assert waitJobs.size() == passiveJobs.size();

    for (int i = 0; i < passiveJobs.size(); i++) {
      GridCollisionJobContext ctx = passiveJobs.get(i);

      if (i > indexOf(waitJobs, ctx))
        ctx.getJobContext().setAttribute(jobAttrKey, getJobPriority(ctx) + starvationInc);
    }
  }
 @Override
 public boolean apply(GridCollisionJobContext ctx) {
   return !ctx.getJobContext().heldcc();
 }