[SR-Users] Using lock() correctly

[Daniel-Constantin Mierla]

Ok, I mixed the part with logs from lua, thinking that there were some
not presented in your example and you just generically referred to them.
Your simplified example is now clear, I will try to reproduce with it.

Meanwhile, the one thing you cans till check is to be sure $ci is the
same in both cases, print it with xlog, but within some chars (quotes,
parenthesis) to be sure the is no white space around it.

Cheers,
Daniel


On 03.07.17 14:43, Sebastian Damm wrote:
> Okay, this is the order from my first mail:
>
> (1) Jun 28 13:27:04 busch /usr/sbin/kamailio[18836]: INFO: <script>: Got
> new packet INVITE: 172.20.21.247 => 172.20.21.4
> (2) Jun 28 13:27:04 busch /usr/sbin/kamailio[18836]: INFO: <script>:
> Obtained lock, calling lua...
> (3) Jun 28 13:27:04 busch /usr/sbin/kamailio[18836]: INFO: app_lua
> [app_lua_sr.c:98]: lua_sr_log(): some logging
> (4) Jun 28 13:27:04 busch /usr/sbin/kamailio[18837]: INFO: <script>: Got
> new packet INVITE: 172.20.21.4 => 172.20.21.247 - Reply Code 407
> (5) Jun 28 13:27:04 busch /usr/sbin/kamailio[18837]: INFO: <script>:
> Obtained lock, calling lua...
> (6) Jun 28 13:27:04 busch /usr/sbin/kamailio[18837]: INFO: <script>: Lua
> finished, released lock...
> (7) Jun 28 13:27:04 busch /usr/sbin/kamailio[18836]: INFO: app_lua
> [app_lua_sr.c:98]: lua_sr_log(): some more logging
>
>
> You see, there are 2 PIDs involved, 18836 and 18837. PID 18836 gets
> the initial INVITE ands starts working. Gets the lock (2). In line
> (3), app_lua logs stuff. Now in line (4) the 407 comes in. PID 18837
> starts working on it. Now it trys to lock the Call-ID, and apparently
> it can get it. But why? You can see in line (7), that PID 18836 is
> still in the lua code, so within the locked part of the config. I
> think, the correct order would be (1) - (2) - (3) - (4) - (7) - (8) -
> (5) - (6), with (8) being the "released lock" message from PID 18836.
> The lines 5 and 6 should'nt be printed before the lock is returned.
>
> I have simplified my code for easier understanding. Threw out lua and
> all stuff, just used sleep from the cfgutils package.
>
> This is what the code looks like:
>
> request_route {
>         xlog("L_INFO", "Got new request ($ci) $rm: $si => $Ri\n");
>         route(magic);
> }
>
> onreply_route {
>         xlog("L_INFO", "Got new reply ($ci) $rm: $si => $Ri - Reply
> Code $rs\n");
>         route(magic);
> }
>
> route[magic] {
>         lock("$ci");
>         xlog("L_INFO", "Obtained lock, sleeping for a second...\n");
>         sleep("1");
>
>         xlog("L_INFO", "Done sleeping, releasing lock...\n");
>         unlock("$ci");
>         xlog("L_INFO", "Released lock...\n");
>
>         drop;
>         exit;
> }
>
>
> And this is what the logs say:
> Jul  3 14:36:06 busch /usr/sbin/kamailio[12273]: INFO: <script>: Got
> new request (313439393038353336363236313137-2m3hb9h5v6o9) INVITE:
> 172.20.21.200 => 172.20.21.4
> Jul  3 14:36:06 busch /usr/sbin/kamailio[12273]: INFO: <script>:
> Obtained lock, sleeping for a second...
> Jul  3 14:36:06 busch /usr/sbin/kamailio[12276]: INFO: <script>: Got
> new reply (313439393038353336363236313137-2m3hb9h5v6o9) INVITE:
> 172.20.21.4 => 172.20.21.200 - Reply Code 407
> Jul  3 14:36:06 busch /usr/sbin/kamailio[12276]: INFO: <script>:
> Obtained lock, sleeping for a second...
> Jul  3 14:36:07 busch /usr/sbin/kamailio[12273]: INFO: <script>: Done
> sleeping, releasing lock...
> Jul  3 14:36:07 busch /usr/sbin/kamailio[12273]: INFO: <script>:
> Released lock...
> Jul  3 14:36:07 busch /usr/sbin/kamailio[12276]: INFO: <script>: Done
> sleeping, releasing lock...
> Jul  3 14:36:07 busch /usr/sbin/kamailio[12276]: INFO: <script>:
> Released lock...
>
> As you can see, both PIDs get the lock on the Call-ID simultaneously.
> From what I think the lock() function should do, the second PID should
> wait for the first one to release the lock.
>
> Best Regards,
> Sebastian
>
> _______________________________________________
> Kamailio (SER) - Users Mailing List
> sr-users at lists.kamailio.org
> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users

-- 
Daniel-Constantin Mierla
www.twitter.com/miconda -- www.linkedin.com/in/miconda
Kamailio Advanced Training - www.asipto.com
Kamailio World Conference - www.kamailioworld.com