objecter: no need to promote lock for monc->renew_subs()

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
objecter: no need to promote lock before send_message()

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
objecter: no need for get_session()

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rwlock: create RWLock::Context

Need for tracking lock state

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
objecter: propagate lock context

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rwlock: can unlock locker explicitly

To simplify certain code path, and help avoiding missed unlock.

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
objecter: use locker instead of explicit lock / unlock

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
rwlock: add promote()

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>
objecter: promote lock and check race

move race checks up the call chain

Signed-off-by: Yehuda Sadeh <yehuda@inktank.com>