Fix: cpu 100% in session.handleLoop

[pantianying]

No description provided.

[fangyincheng]

LGTM

[wongoo]

Is this PR really fix cpu 100% issue?
The info I got is that the value of s.grNum not changing to 1 causes handleLoop() can not break and go into a dead loop. is it correct?
And the community performance test result says that handlePackage may blocked on read and won't exit. Is that correct?

[AlexStocks]

Is this PR really fix cpu 100% issue?
The info I got is that the value of s.grNum not changing to 1 causes handleLoop() can not break and go into a dead loop. is it correct?
And the community performance test result says that handlePackage may blocked on read and won't exit. Is that correct?

Yes, it is for cpu 100% bug fix. The session.handleLoop will run very quickly when the ss.Done is closed but the done select branch can not block when the handlePackage has not exited. And panty add the session.rDone to let the session.handleLoop for-select-done branch block on '<-session.rDone'.

the "handlePackage may blocked on read and won't exit." case is that the handlePackage will try to reconnect the server when it invokes the session.stop(). At last it will exit when it connects the server successfully or this session is closed by upper invoker. However, this case does not matter because it should not block the handleLoop to wait.

[AlexStocks]

LGTM

[wongoo]

LGTM