/** {@inheritDoc} */
  @Override
  public void addAttributeListener(GridTaskSessionAttributeListener lsnr, boolean rewind) {
    A.notNull(lsnr, "lsnr");

    Map<Object, Object> attrs = null;

    List<GridTaskSessionAttributeListener> lsnrs;

    synchronized (mux) {
      lsnrs = new ArrayList<GridTaskSessionAttributeListener>(this.lsnrs.size());

      lsnrs.addAll(this.lsnrs);

      lsnrs.add(lsnr);

      lsnrs = Collections.unmodifiableList(lsnrs);

      this.lsnrs = lsnrs;

      if (rewind) attrs = new HashMap<Object, Object>(this.attrs);
    }

    if (rewind) {
      for (Map.Entry<Object, Object> entry : attrs.entrySet()) {
        for (GridTaskSessionAttributeListener l : lsnrs) {
          l.onAttributeSet(entry.getKey(), entry.getValue());
        }
      }
    }
  }
  /** @param attrs Attributes to set. */
  public void setInternal(Map<?, ?> attrs) {
    A.notNull(attrs, "attrs");

    if (attrs.isEmpty()) return;

    List<GridTaskSessionAttributeListener> lsnrs;

    synchronized (mux) {
      this.attrs.putAll(attrs);

      lsnrs = this.lsnrs;

      mux.notifyAll();
    }

    for (Map.Entry<?, ?> entry : attrs.entrySet())
      for (GridTaskSessionAttributeListener lsnr : lsnrs)
        lsnr.onAttributeSet(entry.getKey(), entry.getValue());
  }
  /** {@inheritDoc} */
  @Override
  public GridFuture<?> addData(Collection<? extends Map.Entry<K, V>> entries) {
    A.notEmpty(entries, "entries");

    enterBusy();

    try {
      GridFutureAdapter<Object> resFut = new GridFutureAdapter<>(ctx);

      activeFuts.add(resFut);

      resFut.listenAsync(rmvActiveFut);

      Collection<K> keys = new GridConcurrentHashSet<>(entries.size(), 1.0f, 16);

      for (Map.Entry<K, V> entry : entries) keys.add(entry.getKey());

      load0(entries, resFut, keys, 0);

      return resFut;
    } finally {
      leaveBusy();
    }
  }
  /**
   * @param entries Entries.
   * @param resFut Result future.
   * @param activeKeys Active keys.
   * @param remaps Remaps count.
   */
  private void load0(
      Collection<? extends Map.Entry<K, V>> entries,
      final GridFutureAdapter<Object> resFut,
      final Collection<K> activeKeys,
      final int remaps) {
    assert entries != null;

    if (remaps >= MAX_REMAP_CNT) {
      resFut.onDone(new GridException("Failed to finish operation (too many remaps): " + remaps));

      return;
    }

    Map<GridNode, Collection<Map.Entry<K, V>>> mappings = new HashMap<>();

    boolean initPda = ctx.deploy().enabled() && jobPda == null;

    for (Map.Entry<K, V> entry : entries) {
      GridNode node;

      try {
        K key = entry.getKey();

        assert key != null;

        if (initPda) {
          jobPda = new DataLoaderPda(key, entry.getValue(), updater);

          initPda = false;
        }

        node = ctx.affinity().mapKeyToNode(cacheName, key);
      } catch (GridException e) {
        resFut.onDone(e);

        return;
      }

      if (node == null) {
        resFut.onDone(
            new GridTopologyException(
                "Failed to map key to node "
                    + "(no nodes with cache found in topology) [infos="
                    + entries.size()
                    + ", cacheName="
                    + cacheName
                    + ']'));

        return;
      }

      Collection<Map.Entry<K, V>> col = mappings.get(node);

      if (col == null) mappings.put(node, col = new ArrayList<>());

      col.add(entry);
    }

    for (final Map.Entry<GridNode, Collection<Map.Entry<K, V>>> e : mappings.entrySet()) {
      final UUID nodeId = e.getKey().id();

      Buffer buf = bufMappings.get(nodeId);

      if (buf == null) {
        Buffer old = bufMappings.putIfAbsent(nodeId, buf = new Buffer(e.getKey()));

        if (old != null) buf = old;
      }

      final Collection<Map.Entry<K, V>> entriesForNode = e.getValue();

      GridInClosure<GridFuture<?>> lsnr =
          new GridInClosure<GridFuture<?>>() {
            @Override
            public void apply(GridFuture<?> t) {
              try {
                t.get();

                for (Map.Entry<K, V> e : entriesForNode) activeKeys.remove(e.getKey());

                if (activeKeys.isEmpty()) resFut.onDone();
              } catch (GridException e1) {
                if (log.isDebugEnabled())
                  log.debug("Future finished with error [nodeId=" + nodeId + ", err=" + e1 + ']');

                if (cancelled) {
                  resFut.onDone(
                      new GridException(
                          "Data loader has been cancelled: " + GridDataLoaderImpl.this, e1));
                } else load0(entriesForNode, resFut, activeKeys, remaps + 1);
              }
            }
          };

      GridFutureAdapter<?> f;

      try {
        f = buf.update(entriesForNode, lsnr);
      } catch (GridInterruptedException e1) {
        resFut.onDone(e1);

        return;
      }

      if (ctx.discovery().node(nodeId) == null) {
        if (bufMappings.remove(nodeId, buf)) buf.onNodeLeft();

        if (f != null)
          f.onDone(
              new GridTopologyException(
                  "Failed to wait for request completion " + "(node has left): " + nodeId));
      }
    }
  }