[Freeswitch-users] session_locate and deadlocks

Hello, I'm trying to passthrough some events from one leg of a bridged session to the other leg: notify-talk and hold. talk was an easy one. However, regarding the hold, I'm afraid of deadlocks, because I will be modying the peer-session (putting it on hold), which will also try to modify the originating leg (play hold-music). So, can a session get a readlock on a session that is currenly processing a request? I have the impression that there are higher-level-locks on sip-level. So, my question is: What is the function of the readlock created by "switch_core_session_locate" ? And, can multiple locks be acquired (think so), but what should I watch out for then? Thanks, Michel