heartbeat thread is sometimes not terminated upon client closing

I am running into a frequent issue where the heartbeat thread does not get interrupted properly when close my SSHClient object. This happens often when the sshClient.connect is refused (I have a retry mechanism that retries this up to 20 times with fixed interval 10 second sleep). This leads to my application not exiting. Let me know if more information is needed -- I could attempt to write an isolated program to reproduce the issue.

If I had to guess it might be some sort of deadlock with the writeLock in TransportImpl as the Heartbeater needs to obtain that lock in its loop when it does a write(...)