fix read lock netst

[orientlu]

Is this a bug or a feature request?

is a bug， the same as issues #118

What did you expect?

merge pr，and we should find how to avoid this situaction again

What happened?

handlePushData get rlock
and then handleTXACK require again；

What version are your using?

How can your issue be reproduced?

Could you share your log output?