===
=== <pending> <lock#> (<file>): <lock type> <line num> <function> <lock name> <lock addr> (times locked)
===
=== Thread ID: 0x7f3ae3616700 (do_monitor           started at [28958] chan_sip.c restart_monitor())
=== ---> Lock #0 (chan_sip.c): MUTEX 28929 do_monitor &monlock 0x7f3ae708d440 (1)
        /usr/sbin/asterisk(ast_bt_get_addresses+0x1d) [0x5107aa]
        /usr/sbin/asterisk(__ast_pthread_mutex_lock+0xe0) [0x508417]
        /usr/lib/asterisk/modules/chan_sip.so(+0x993f9) [0x7f3ae6e353f9]
        /usr/sbin/asterisk() [0x5a38c1]
        /lib/x86_64-linux-gnu/libpthread.so.0(+0x7e9a) [0x7f3b35ff8e9a]
        /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d) [0x7f3b3713e3fd]