/** Initializes future. */
  @SuppressWarnings({"unchecked"})
  void finish() {
    if (mappings != null) {
      finish(mappings.values());

      markInitialized();

      if (!isSync()) {
        boolean complete = true;

        for (GridFuture<?> f : pending())
          // Mini-future in non-sync mode gets done when message gets sent.
          if (isMini(f) && !f.isDone()) complete = false;

        if (complete) onComplete();
      }
    } else {
      assert !commit;

      try {
        tx.rollback();
      } catch (GridException e) {
        U.error(log, "Failed to rollback empty transaction: " + tx, e);
      }

      markInitialized();
    }
  }
  /** @param e Error. */
  void onError(Throwable e) {
    tx.commitError(e);

    if (err.compareAndSet(null, e)) {
      boolean marked = tx.setRollbackOnly();

      if (e instanceof GridCacheTxRollbackException)
        if (marked) {
          try {
            tx.rollback();
          } catch (GridException ex) {
            U.error(log, "Failed to automatically rollback transaction: " + tx, ex);
          }
        }

      onComplete();
    }
  }