运行Firebase事务无效。可能是什么原因？

Question

我正在尝试为我正在制作的应用中的帖子更新费率计数器，同时还为用户增加了一个投票计数器。执行此操作的正确方法是使用事务。但是当我运行交易时，没有任何反应。可能是什么原因？这是我的代码：

    private void rate(String id, final int rateCount) {

    final DatabaseReference users = FirebaseDatabase.getInstance().getReference("users");

    FirebaseDatabase.getInstance().getReference("posts").child(id)
            .runTransaction(new Transaction.Handler() {
                @Override
                public Transaction.Result doTransaction(MutableData mutableData) {
                    Post p = new Post("","","");
                    if (mutableData.getValue(Post.class) != null) {
                        p = mutableData.getValue(Post.class);
                    }

                        p.setPointsCount(p.getPointsCount() + rateCount);
                        p.rates.put(userPrefs.getId(), rateCount);

                    users.child(p.getUploader()).runTransaction(new Transaction.Handler() {
                        @Override
                        public Transaction.Result doTransaction(MutableData mutableData) {
                            User p = mutableData.getValue(User.class);
                            if (p == null) {
                                return Transaction.success(mutableData);
                            }
                            p.setPoints(p.getPoints() + rateCount);
                            mutableData.setValue(p);
                            return Transaction.success(mutableData);
                        }

                        @Override
                        public void onComplete(DatabaseError databaseError, boolean b, DataSnapshot dataSnapshot) {

                        }
                    });
                    // Set value and report transaction success
                    mutableData.setValue(p);
                    return Transaction.success(mutableData);
                }

                @Override
                public void onComplete(DatabaseError databaseError, boolean b,
                                       DataSnapshot dataSnapshot) {
                    Log.w("Rate", "Rated Successfully!          <-----|");
                    // Transaction completed
                }
            });
}