/** {@inheritDoc} */
  @Override
  public boolean waitForAttributes(Map<?, ?> attrs, long timeout) throws InterruptedException {
    A.notNull(attrs, "attrs");

    if (attrs.isEmpty()) {
      return true;
    }

    if (timeout == 0) timeout = Long.MAX_VALUE;

    long now = System.currentTimeMillis();

    // Prevent overflow.
    long end = now + timeout < 0 ? Long.MAX_VALUE : now + timeout;

    // Don't wait longer than session timeout.
    if (end > endTime) end = endTime;

    synchronized (mux) {
      boolean isFound = false;

      while (!closed
          && !(isFound = this.attrs.entrySet().containsAll(attrs.entrySet()))
          && now < end) {
        mux.wait(end - now);

        now = System.currentTimeMillis();
      }

      if (closed) throw new InterruptedException("Session was closed: " + this);

      return isFound;
    }
  }
  /** {@inheritDoc} */
  @Override
  public void setAttributes(Map<?, ?> attrs) throws GridException {
    A.notNull(attrs, "attrs");

    if (attrs.isEmpty()) return;

    // Note that there is no mux notification in this block.
    // The reason is that we wait for ordered attributes to
    // come back from task prior to notification. The notification
    // will happen in 'setInternal(...)' method.
    synchronized (mux) {
      this.attrs.putAll(attrs);
    }

    if (isTaskNode()) ctx.task().setAttributes(this, attrs);
  }
  /** @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());
  }