/** {@inheritDoc} */
  @Override
  public void writeExternal(ObjectOutput out) throws IOException {
    boolean done;
    boolean cancelled;
    Object res;
    Throwable err;
    boolean syncNotify;
    boolean concurNotify;

    synchronized (mux) {
      done = this.done;
      cancelled = this.cancelled;
      res = this.res;
      err = this.err;
      syncNotify = this.syncNotify;
      concurNotify = this.concurNotify;
    }

    out.writeBoolean(done);
    out.writeBoolean(syncNotify);
    out.writeBoolean(concurNotify);

    // Don't write any further if not done, as deserialized future
    // will be invalid anyways.
    if (done) {
      out.writeBoolean(cancelled);
      out.writeObject(res);
      out.writeObject(err);
    }
  }
  /** {@inheritDoc} */
  @Override
  public void writeExternal(ObjectOutput out) throws IOException {
    super.writeExternal(out);

    out.writeLong(threadId);
    out.writeBoolean(commit);
    out.writeBoolean(invalidate);
    out.writeBoolean(reply);

    U.writeGridUuid(out, futId);
    CU.writeVersion(out, commitVer);
    CU.writeVersion(out, baseVer);

    U.writeCollection(out, writeEntries);
  }
  /** {@inheritDoc} */
  @Override
  public void writeExternal(ObjectOutput out) throws IOException {
    super.writeExternal(out);

    out.writeLong(topVer);
    out.writeBoolean(implicitTx);
    out.writeBoolean(implicitSingleTx);
    out.writeBoolean(syncCommit);
    out.writeBoolean(syncRollback);
    out.writeObject(filterBytes);

    U.writeArray(out, dhtVers);

    assert miniId != null;

    U.writeGridUuid(out, miniId);
  }
  /** {@inheritDoc} */
  @Override
  public void writeExternal(ObjectOutput out) throws IOException {
    out.writeBoolean(depEnabled);

    if (depEnabled) {
      U.writeByteArray(out, topicBytes);
      U.writeByteArray(out, predBytes);
      U.writeString(out, clsName);
      out.writeObject(depInfo);
    } else {
      out.writeObject(topic);
      out.writeObject(pred);
    }
  }