/** {@inheritDoc} */
  @Override
  public void onCollision(
      Collection<GridCollisionJobContext> waitJobs,
      Collection<GridCollisionJobContext> activeJobs) {
    assert waitJobs != null;
    assert activeJobs != null;

    int activeSize = F.size(activeJobs, RUNNING_JOBS);

    waitingCnt.set(waitJobs.size());
    runningCnt.set(activeSize);
    heldCnt.set(activeJobs.size() - activeSize);

    int waitSize = waitJobs.size();

    int activateCnt = parallelJobsNum - activeSize;

    if (activateCnt > 0 && !waitJobs.isEmpty()) {
      if (waitJobs.size() <= activateCnt) {
        for (GridCollisionJobContext waitJob : waitJobs) {
          waitJob.activate();

          waitSize--;
        }
      } else {
        List<GridCollisionJobContext> passiveList =
            new ArrayList<GridCollisionJobContext>(waitJobs);

        Collections.sort(
            passiveList,
            new Comparator<GridCollisionJobContext>() {
              /** {@inheritDoc} */
              @Override
              public int compare(GridCollisionJobContext o1, GridCollisionJobContext o2) {
                int p1 = getJobPriority(o1);
                int p2 = getJobPriority(o2);

                return p1 < p2 ? 1 : p1 == p2 ? 0 : -1;
              }
            });

        if (preventStarvation) bumpPriority(waitJobs, passiveList);

        for (int i = 0; i < activateCnt; i++) {
          passiveList.get(i).activate();

          waitSize--;
        }
      }
    }

    if (waitSize > waitJobsNum) {
      List<GridCollisionJobContext> waitList = new ArrayList<GridCollisionJobContext>(waitJobs);

      // Put jobs with highest priority first.
      Collections.sort(
          waitList,
          new Comparator<GridCollisionJobContext>() {
            /** {@inheritDoc} */
            @Override
            public int compare(GridCollisionJobContext o1, GridCollisionJobContext o2) {
              int p1 = getJobPriority(o1);
              int p2 = getJobPriority(o2);

              return p1 < p2 ? 1 : p1 == p2 ? 0 : -1;
            }
          });

      int skip = waitJobs.size() - waitSize;

      int i = 0;

      for (GridCollisionJobContext waitCtx : waitList) {
        if (++i >= skip) {
          waitCtx.cancel();

          if (--waitSize <= waitJobsNum) break;
        }
      }
    }
  }
 /** {@inheritDoc} */
 @Override
 public Map<String, Object> getNodeAttributes() throws GridSpiException {
   return F.<String, Object>asMap(
       createSpiAttributeName(PRIORITY_ATTRIBUTE_KEY), getPriorityAttributeKey());
 }