[RFC] Subscriber Reference Counting

Hi, IIRC Harald et all. were seeing GSM subscriber leakage at HAR2009 and we have not yet explored the cause of this problem. I would like to have no subscriber leaks for the congress and propose the following changes. I have pushed the "holger/subscr-ref-handling" branch to our repository and would be happy if people could give it a spin. My testing here is pretty limited. Currently I have two commits. The second is removing a leak in the vty console for SMS sending and subscriber usage and the other patch is trying to stop borrowing someone else's gsm_subscriber reference. More details below. Currently we do lchan->subscr = new_subscr and then we have two flavors of checking if the channel is already used. I have changed this to use a new assignment function that will do the check consistently and updated call sites. I would establish the following guideline for gsm_subscriber handling: In every method where subscr_get* is called the subscriber must be released at the exit with subscr_put unless the referenced provider is assigned to a struct that is created in the same method, then the subscriber must be released next to the talloc_free. More details: - paging.c seems fine - gsm_subscriber_chan seems fine - gsm_04_08_utils.c seems fine - gsm_04_08.c seems fine now as well. subscr_get/_put should be balanced - gsm_04_11.c if we leak a subscriber we also leak a sms I have not checked all SMS paths to be sure we don't leak there. I would be very happy if people could test this. z,