[sr-dev] TM possible deadlock

Wed Apr 9 23:26:17 CEST 2014

Hey Daniel,

nothing extraordinary...

# -- TM params --
modparam("tm", "fr_timer", 20000);
modparam("tm", "fr_inv_timer", 10000)

Cheers
Jason

On Wed, Apr 9, 2014 at 10:32 PM, Jason Penton <jason.penton at gmail.com>wrote:

> Hey Daniel,
>
> Yes I did a test with a very basic config file and I am not able to
> re-create. However, with my *complex* cfg file I can re-create every time.
> Tomorrow I will compare what is different and report back... hopefully with
> fix ;)
>
> here is bt of timer process deadlocking itself:
>
> #0  syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:39
> #1  0x00007f5009f22004 in futex_get (lock=0x7f4fc55030d8) at
> ../../mem/../futexlock.h:123
> #2  0x00007f5009f223e1 in _lock (s=0x7f4fc55030d8, file=0x7f5009f90fd1
> "t_cancel.c", function=0x7f5009f91980 "cancel_branch", line=250) at
> lock.h:99
> #3  0x00007f5009f23271 in cancel_branch (t=0x7f4fc5501b40, branch=0,
> reason=0x7fff646d03a8, flags=3) at t_cancel.c:250
> #4  0x00007f5009f22c02 in cancel_uacs (t=0x7f4fc5501b40,
> cancel_data=0x7fff646d03a0, flags=1) at t_cancel.c:123
> #5  0x00007f5009f718c4 in _reply_light (trans=0x7f4fc5501b40,
>     buf=0x7f500a24dc68 "SIP/2.0 500 Server error on LIR select next
> S-CSCF\r\nVia: SIP/2.0/UDP 10.0.1.167:6060;branch=z9hG4bKb7.2ae09f29ffbd0034cd6d58483053603b.1\r\nVia:
> SIP/2.0/UDP 10.0.1.166:4060;branch=z9hG4bKb7.3faa03ddea80"..., len=778,
> code=500, to_tag=0x7f500a1c7ae0 "c82b15d7f12ef185f95fe4945457d449-8bab",
> to_tag_len=37, lock=0, bm=0x7fff646d0b60) at t_reply.c:660
> #6  0x00007f5009f7244c in _reply (trans=0x7f4fc5501b40,
> p_msg=0x7f500a1c6bc0, code=500, text=0x7f500a249a48 "Server error on LIR
> select next S-CSCF", lock=0) at t_reply.c:795
> #7  0x00007f5009f76436 in t_reply_unsafe (t=0x7f4fc5501b40,
> p_msg=0x7f500a1c6bc0, code=500, text=0x7f500a249a48 "Server error on LIR
> select next S-CSCF") at t_reply.c:1643
> #8  0x00007f5009f57621 in w_t_reply (msg=0x7f500a1c6bc0, p1=0x7f500a2497d8
> "\340\332$\nP\177", p2=0x7f500a249870 "h\321$\nP\177") at tm.c:1324
> #9  0x000000000041a700 in do_action (h=0x7fff646d1d30, a=0x7f500a24cee8,
> msg=0x7f500a1c6bc0) at action.c:1119
> #10 0x0000000000423831 in run_actions (h=0x7fff646d1d30, a=0x7f500a24cee8,
> msg=0x7f500a1c6bc0) at action.c:1607
> #11 0x000000000041a5a4 in do_action (h=0x7fff646d1d30, a=0x7f500a24d478,
> msg=0x7f500a1c6bc0) at action.c:1102
> #12 0x0000000000423831 in run_actions (h=0x7fff646d1d30, a=0x7f500a249148,
> msg=0x7f500a1c6bc0) at action.c:1607
> #13 0x000000000041a54e in do_action (h=0x7fff646d1d30, a=0x7f500a24c500,
> msg=0x7f500a1c6bc0) at action.c:1098
> #14 0x0000000000423831 in run_actions (h=0x7fff646d1d30, a=0x7f500a247a28,
> msg=0x7f500a1c6bc0) at action.c:1607
> #15 0x0000000000423fdf in run_top_route (a=0x7f500a247a28,
> msg=0x7f500a1c6bc0, c=0x0) at action.c:1693
> #16 0x00007f5009f73815 in run_failure_handlers (t=0x7f4fc5501b40,
> rpl=0xffffffffffffffff, code=408, extra_flags=96) at t_reply.c:1061
> #17 0x00007f5009f7527a in t_should_relay_response (Trans=0x7f4fc5501b40,
> new_code=408, branch=1, should_store=0x7fff646d201c,
> should_relay=0x7fff646d2018, cancel_data=0x7fff646d2070,
>     reply=0xffffffffffffffff) at t_reply.c:1416
> #18 0x00007f5009f76ede in relay_reply (t=0x7f4fc5501b40,
> p_msg=0xffffffffffffffff, branch=1, msg_status=408,
> cancel_data=0x7fff646d2070, do_put_on_wait=0) at t_reply.c:1819
> #19 0x00007f5009f44c88 in fake_reply (t=0x7f4fc5501b40, branch=1,
> code=408) at timer.c:354
> #20 0x00007f5009f450e7 in final_response_handler (r_buf=0x7f4fc5501e60,
> t=0x7f4fc5501b40) at timer.c:526
> #21 0x00007f5009f4518d in retr_buf_handler (ticks=260027386,
> tl=0x7f4fc5501e80, p=0x3e8) at timer.c:584
> #22 0x0000000000544119 in timer_list_expire (t=260027386,
> h=0x7f4fc527cbe0, slow_l=0x7f4fc527cdf0, slow_mark=0) at timer.c:894
> #23 0x0000000000544418 in timer_handler () at timer.c:959
> #24 0x00000000005446b2 in timer_main () at timer.c:998
> #25 0x0000000000471ddf in main_loop () at main.c:1689
>
>
>
> On Wed, Apr 9, 2014 at 9:34 PM, Daniel-Constantin Mierla <
> miconda at gmail.com> wrote:
>
>>  Hello,
>>
>> that should not be a very rare case and I would expect to be caught so
>> far, anyhow ... this looks like easy to reproduce, have you tried it?
>>
>> You can have two kamailio, one relying the invite to the second, which
>> will reply with 100, then wait for the timeout on the first instance. You
>> can add some debug messages in the code to see if the lock is called twice.
>>
>> Cheers,
>> Daniel
>>
>>
>> On 09/04/14 17:51, Jason Penton wrote:
>>
>> Hi All,
>>
>>  I have been experiencing a deadlock when a timeout occurs on a
>> t_relayed() INVITE. Going through the code I have noticed a possible chance
>> of deadlock (without re-entrant enabled). Here is my thinking:
>>
>>  t_should_relay_response() is called with REPLY_LOCK when the timer
>> process fires on the fr_inv_timer (no response from the INVITE that was
>> relayed, other than 100 provisional) and a 408 is generated. However, from
>> within that function there are calls to run_failure_handlers() which in
>> turn *could* try and lock the reply (viz. somebody having a t_reply() call
>> in the cfg file - in failure route block). This would result in another
>> lock on the same transaction's REPLY_LOCK....
>>
>>  Has anybody else experienced something like this?
>>
>>  this is on master btw.
>>
>>  Cheers
>> Jason
>>
>>
>> _______________________________________________
>> sr-dev mailing listsr-dev at lists.sip-router.orghttp://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev
>>
>>
>> --
>> Daniel-Constantin Mierla - http://www.asipto.comhttp://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
>>
>>
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>>
>>
>
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