/**
   * Removes given value from the set and returns the instance stored in the set or {@code null} if
   * value was not found.
   *
   * @param val Value to remove.
   * @return The instance that was stored in the set or {@code null}.
   */
  @Nullable
  public V removex(V val) {
    A.notNull(val, "val");

    if (comp == null || !strict) {
      for (Iterator<V> it = vals.iterator(); it.hasNext(); ) {
        V v = it.next();

        if (v.equals(val)) {
          it.remove();

          return v;
        }
      }

      return null;
    }

    assert comp != null && strict;

    for (Iterator<V> it = vals.iterator(); it.hasNext(); ) {
      V v = it.next();

      // Prefer equals to comparator.
      if (v.equals(val)) {
        it.remove();

        return v;
      }

      if (comp.compare(v, val) > 0) break;
    }

    return null;
  }
  /**
   * Waits for renting partitions.
   *
   * @return {@code True} if mapping was changed.
   * @throws IgniteCheckedException If failed.
   */
  private boolean waitForRent() throws IgniteCheckedException {
    boolean changed = false;

    // Synchronously wait for all renting partitions to complete.
    for (Iterator<GridDhtLocalPartition> it = locParts.values().iterator(); it.hasNext(); ) {
      GridDhtLocalPartition p = it.next();

      GridDhtPartitionState state = p.state();

      if (state == RENTING || state == EVICTED) {
        if (log.isDebugEnabled()) log.debug("Waiting for renting partition: " + p);

        // Wait for partition to empty out.
        p.rent(true).get();

        if (log.isDebugEnabled()) log.debug("Finished waiting for renting partition: " + p);

        // Remove evicted partition.
        it.remove();

        changed = true;
      }
    }

    return changed;
  }
  /** {@inheritDoc} */
  @Override
  public void explicitUndeploy(UUID nodeId, String rsrcName) {
    Collection<SharedDeployment> undeployed = new LinkedList<SharedDeployment>();

    synchronized (mux) {
      for (Iterator<List<SharedDeployment>> i1 = cache.values().iterator(); i1.hasNext(); ) {
        List<SharedDeployment> deps = i1.next();

        for (Iterator<SharedDeployment> i2 = deps.iterator(); i2.hasNext(); ) {
          SharedDeployment dep = i2.next();

          if (dep.hasName(rsrcName)) {
            if (!dep.isUndeployed()) {
              dep.undeploy();

              dep.onRemoved();

              // Undeploy.
              i2.remove();

              undeployed.add(dep);

              if (log.isInfoEnabled()) log.info("Undeployed per-version class loader: " + dep);
            }

            break;
          }
        }

        if (deps.isEmpty()) i1.remove();
      }
    }

    recordUndeployed(null, undeployed);
  }
  /**
   * @param ldr Class loader to undeploy.
   * @param recEvt Whether or not to record the event.
   */
  private void undeploy(ClassLoader ldr, boolean recEvt) {
    Collection<GridDeployment> doomed = new HashSet<GridDeployment>();

    synchronized (mux) {
      for (Iterator<LinkedList<GridDeployment>> i1 = cache.values().iterator(); i1.hasNext(); ) {
        LinkedList<GridDeployment> deps = i1.next();

        for (Iterator<GridDeployment> i2 = deps.iterator(); i2.hasNext(); ) {
          GridDeployment dep = i2.next();

          if (dep.classLoader() == ldr) {
            dep.undeploy();

            i2.remove();

            doomed.add(dep);

            if (log.isInfoEnabled()) {
              log.info("Removed undeployed class: " + dep);
            }
          }
        }

        if (deps.isEmpty()) {
          i1.remove();
        }
      }
    }

    for (GridDeployment dep : doomed) {
      if (dep.isObsolete()) {
        // Resource cleanup.
        ctx.resource().onUndeployed(dep);
      }

      if (recEvt) {
        recordUndeploy(dep, true);
      }
    }
  }
  /** {@inheritDoc} */
  @SuppressWarnings({"MismatchedQueryAndUpdateOfCollection"})
  @Nullable
  @Override
  public GridDhtPartitionMap update(
      @Nullable GridDhtPartitionExchangeId exchId, GridDhtPartitionFullMap partMap) {
    if (log.isDebugEnabled())
      log.debug(
          "Updating full partition map [exchId=" + exchId + ", parts=" + fullMapString() + ']');

    assert partMap != null;

    lock.writeLock().lock();

    try {
      if (stopping) return null;

      if (exchId != null && lastExchangeId != null && lastExchangeId.compareTo(exchId) >= 0) {
        if (log.isDebugEnabled())
          log.debug(
              "Stale exchange id for full partition map update (will ignore) [lastExchId="
                  + lastExchangeId
                  + ", exchId="
                  + exchId
                  + ']');

        return null;
      }

      if (node2part != null && node2part.compareTo(partMap) >= 0) {
        if (log.isDebugEnabled())
          log.debug(
              "Stale partition map for full partition map update (will ignore) [lastExchId="
                  + lastExchangeId
                  + ", exchId="
                  + exchId
                  + ", curMap="
                  + node2part
                  + ", newMap="
                  + partMap
                  + ']');

        return null;
      }

      long updateSeq = this.updateSeq.incrementAndGet();

      if (exchId != null) lastExchangeId = exchId;

      if (node2part != null) {
        for (GridDhtPartitionMap part : node2part.values()) {
          GridDhtPartitionMap newPart = partMap.get(part.nodeId());

          // If for some nodes current partition has a newer map,
          // then we keep the newer value.
          if (newPart != null && newPart.updateSequence() < part.updateSequence()) {
            if (log.isDebugEnabled())
              log.debug(
                  "Overriding partition map in full update map [exchId="
                      + exchId
                      + ", curPart="
                      + mapString(part)
                      + ", newPart="
                      + mapString(newPart)
                      + ']');

            partMap.put(part.nodeId(), part);
          }
        }

        for (Iterator<UUID> it = partMap.keySet().iterator(); it.hasNext(); ) {
          UUID nodeId = it.next();

          if (!cctx.discovery().alive(nodeId)) {
            if (log.isDebugEnabled())
              log.debug(
                  "Removing left node from full map update [nodeId="
                      + nodeId
                      + ", partMap="
                      + partMap
                      + ']');

            it.remove();
          }
        }
      }

      node2part = partMap;

      Map<Integer, Set<UUID>> p2n = new HashMap<>(cctx.affinity().partitions(), 1.0f);

      for (Map.Entry<UUID, GridDhtPartitionMap> e : partMap.entrySet()) {
        for (Integer p : e.getValue().keySet()) {
          Set<UUID> ids = p2n.get(p);

          if (ids == null)
            // Initialize HashSet to size 3 in anticipation that there won't be
            // more than 3 nodes per partitions.
            p2n.put(p, ids = U.newHashSet(3));

          ids.add(e.getKey());
        }
      }

      part2node = p2n;

      boolean changed = checkEvictions(updateSeq);

      consistencyCheck();

      if (log.isDebugEnabled()) log.debug("Partition map after full update: " + fullMapString());

      return changed ? localPartitionMap() : null;
    } finally {
      lock.writeLock().unlock();
    }
  }
  /** {@inheritDoc} */
  @Override
  public void onKernalStart() throws GridException {
    discoLsnr =
        new GridLocalEventListener() {
          @Override
          public void onEvent(GridEvent evt) {
            assert evt instanceof GridDiscoveryEvent;

            assert evt.type() == EVT_NODE_LEFT || evt.type() == EVT_NODE_FAILED;

            GridDiscoveryEvent discoEvt = (GridDiscoveryEvent) evt;

            Collection<SharedDeployment> undeployed = new LinkedList<SharedDeployment>();

            if (log.isDebugEnabled()) log.debug("Processing node departure event: " + evt);

            synchronized (mux) {
              for (Iterator<List<SharedDeployment>> i1 = cache.values().iterator();
                  i1.hasNext(); ) {
                List<SharedDeployment> deps = i1.next();

                for (Iterator<SharedDeployment> i2 = deps.iterator(); i2.hasNext(); ) {
                  SharedDeployment dep = i2.next();

                  dep.removeParticipant(discoEvt.eventNodeId());

                  if (!dep.hasParticipants()) {
                    if (dep.deployMode() == SHARED) {
                      if (!dep.isUndeployed()) {
                        dep.undeploy();

                        // Undeploy.
                        i2.remove();

                        assert !dep.isRemoved();

                        dep.onRemoved();

                        undeployed.add(dep);

                        if (log.isDebugEnabled())
                          log.debug(
                              "Undeployed class loader as there are no participating "
                                  + "nodes: "
                                  + dep);
                      }
                    } else if (log.isDebugEnabled())
                      log.debug("Preserving deployment without node participants: " + dep);
                  } else if (log.isDebugEnabled())
                    log.debug("Keeping deployment as it still has participants: " + dep);
                }

                if (deps.isEmpty()) i1.remove();
              }
            }

            recordUndeployed(discoEvt.eventNodeId(), undeployed);
          }
        };

    ctx.event().addLocalEventListener(discoLsnr, EVT_NODE_FAILED, EVT_NODE_LEFT);

    Collection<SharedDeployment> undeployed = new LinkedList<SharedDeployment>();

    synchronized (mux) {
      for (Iterator<List<SharedDeployment>> i1 = cache.values().iterator(); i1.hasNext(); ) {
        List<SharedDeployment> deps = i1.next();

        for (Iterator<SharedDeployment> i2 = deps.iterator(); i2.hasNext(); ) {
          SharedDeployment dep = i2.next();

          for (UUID nodeId : dep.getParticipantNodeIds())
            if (ctx.discovery().node(nodeId) == null) dep.removeParticipant(nodeId);

          if (!dep.hasParticipants()) {
            if (dep.deployMode() == SHARED) {
              if (!dep.isUndeployed()) {
                dep.undeploy();

                // Undeploy.
                i2.remove();

                dep.onRemoved();

                undeployed.add(dep);

                if (log.isDebugEnabled())
                  log.debug("Undeployed class loader as there are no participating nodes: " + dep);
              }
            } else if (log.isDebugEnabled())
              log.debug("Preserving deployment without node participants: " + dep);
          } else if (log.isDebugEnabled())
            log.debug("Keeping deployment as it still has participants: " + dep);
        }

        if (deps.isEmpty()) i1.remove();
      }
    }

    recordUndeployed(null, undeployed);

    if (log.isDebugEnabled()) log.debug("Registered deployment discovery listener: " + discoLsnr);
  }