[Libevent-users] Assertion fails in insert_common_timeout

I am using libevent-2.0.18-stable running on Liux (CentOs 6.2).

Adding an event with a common timeout I get an assertion failure in insert_common_timeout_inorder (event.c:2532): “EVUTIL_ASSERT(is_same_common_timeout(&e->ev_timeout, &ev->ev_timeout));”

This happens once every few days on a libevent based HTTP proxy and I do not know how to consistently reproduce it.

Examining the core file

--------------------------------

*the stack*

#0 0x0000003c72c32885 in raise () from /lib64/libc.so.6

#1 0x0000003c72c34065 in abort () from /lib64/libc.so.6

#2 0x00007f35216c735e in event_exit (eval=-559030611, fmt=<value optimized out>) at log.c:79

#3 event_errx (eval=-559030611, fmt=<value optimized out>) at log.c:136

#4 0x00007f35216b5b65 in insert_common_timeout_inorder (base=0x7f34e8369860, ev=0x7f34e851c098, queue=1) at event.c:2532

#5 event_queue_insert (base=0x7f34e8369860, ev=0x7f34e851c098, queue=1) at event.c:2576

#6 0x00007f35216b72ca in event_add_internal (ev=0x7f34e851c098, tv=0x1f986248, tv_is_absolute=0) at event.c:2125

#7 0x00007f35216b783a in event_add (ev=0x7f34e851c098, tv=0x1f986248) at event.c:1941

#8 0x00007f35237a1fbb in AddEventsForPxcn (pxcn=..., handler_data=...) at tcpproxy.cpp:665

#9 0x00007f35237a483d in notify_conn_fn (fd=89, what=<value optimized out>, arg=0x1f986238) at tcpproxy.cpp:827

*the added event and timeout*

(gdb) frame 7

#7 0x00007f35216b783a in event_add (ev=0x7f34e851c098, tv=0x1f986248) at event.c:1941

1941 event.c: No such file or directory.

in event.c

(gdb) p *tv

$1 = {tv_sec = 5, tv_usec = 1342177280}

(gdb) p *ev

$4 = {ev_active_next = {tqe_next = 0x0, tqe_prev = 0x1b7489a0}, ev_next = {tqe_next = 0x0, tqe_prev = 0x7f34e851c130}, ev_timeout_pos = {

ev_next_with_common_timeout = {tqe_next = 0x7f34ffffffff, tqe_prev = 0x7f34e87cd4e0}, min_heap_idx = -1}, ev_fd = 213, ev_base = 0x7f34e8369860, _ev = {

ev_io = {ev_io_next = {tqe_next = 0x0, tqe_prev = 0x7f34e8369f40}, ev_timeout = {tv_sec = 5, tv_usec = 1342177280}}, ev_signal = {ev_signal_next = {

tqe_next = 0x0, tqe_prev = 0x7f34e8369f40}, ev_ncalls = 5, ev_pncalls = 0x50000000}}, ev_events = 50, ev_res = 0, ev_flags = 131, ev_pri = 0 '\000',

ev_closure = 2 '\002', ev_timeout = {tv_sec = 266477, tv_usec = 1342841591}, ev_callback = 0x7f352379fab0 <receiver_cb(int, short, void*)>,

ev_arg = 0x7f34e851c088}

*in the point of the assertion*

(gdb) frame 4

#4 0x00007f35216b5b65 in insert_common_timeout_inorder (base=0x7f34e8369860, ev=0x7f34e851c098, queue=1) at event.c:2532

2532 in event.c

(gdb) p ev->ev_timeout

value has been optimized out

(gdb) p e->ev_timeout

value has been optimized out

*seeing ev that is optimized out at the point of assertion*

(gdb) frame 5

#5 event_queue_insert (base=0x7f34e8369860, ev=0x7f34e851c098, queue=1) at event.c:2576

2576 in event.c

(gdb) p ev->ev_timeout

$12 = {tv_sec = 266477, tv_usec = 1342841591}

*seeing e that is optimized out at the point of assertion (hope I got it right)*

(gdb) p (*(((struct event_list *)((&base->common_timeout_queues->events)->tqh_last))->tqh_last))->ev_timeout

$18 = {tv_sec = 0, tv_usec = 0}

(gdb) p ((*(((struct event_list *)((&base->common_timeout_queues->events)->tqh_last))->tqh_last))->ev_timeout_pos.ev_next_with_common_timeout)

$19 = {tqe_next = 0x30000000000, tqe_prev = 0x0}

Any clue or advise can help.

Thanks,

Avi

[Libevent-users] Assertion fails in insert_common_timeout_inorder