I see that you've elected to not implement a closed flag i.e. to not
defer the closing of the native SCTP socket pointer in case the close
method is invoked by a thread which is already in possession of the
readLock. Does it mean that you believe our current execution graph
does not include such a path? If you're not sure, then I still think
that there is such a possibility and then the close method will not be
able to acquire the writeLock and, effectively, will cause a deadlock.