ZMQ crash problem on ubuntu

[wushuangge]

Issue description

Here is the error message debugged from the coredump file:

[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `./verifier'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007ff5d4005cf0 in ?? ()
[Current thread is 1 (Thread 0x7ff5e8000700 (LWP 15101))]
(gdb) bt
#0 0x00007ff5d4005cf0 in ?? ()
#1 0x000000000093aa47 in zmq::pipe_t::check_read (this=0x7ff5d4005cc0) at src/pipe.cpp:166
#2 0x0000000000957b90 in zmq::fq_t::has_in (this=0x7ff5d4005120) at src/fq.cpp:139
#3 0x00000000009403f5 in zmq::socket_base_t::has_in (this=0x7ff5d4004b60) at src/socket_base.cpp:1274
#4 zmq::socket_base_t::getsockopt (this=0x7ff5d4004b60, option_=option_@entry=15, optval_=optval_@entry=0x7ff5e7fff6d4,
optvallen_=optvallen_@entry=0x7ff5e7fff6d8) at src/socket_base.cpp:458
#5 0x00000000009240ba in zmq_getsockopt (s_=, option_=option_@entry=15,
optval_=optval_@entry=0x7ff5e7fff6d4, optvallen_=optvallen_@entry=0x7ff5e7fff6d8) at src/zmq.cpp:267
#6 0x000000000092500d in zmq_poll (items_=0x7ff5e7fff820, nitems_=1, timeout_=10) at src/zmq.cpp:943
#7 0x000000000061f42e in ZmqWorker::run (this=0x2363e60) at /home/wsg/detector_sdk/src/zmqServer/ZmqServer.cpp:26
#8 0x000000000063b687 in std::_Mem_fn_base<void (ZmqWorker::)(), true>::operator()<, void>(ZmqWorker) const (
this=0x2363f20, __object=0x2363e60) at /usr/include/c++/5/functional:600
#9 0x000000000063b5b3 in std::_Bind_simple<std::_Mem_fn<void (ZmqWorker::)()> (ZmqWorker)>::_M_invoke<0ul>(std::_Index_tuple<0ul>) (this=0x2363f18) at /usr/include/c++/5/functional:1531
#10 0x000000000063b35d in std::_Bind_simple<std::_Mem_fn<void (ZmqWorker::)()> (ZmqWorker)>::operator()() (this=0x2363f18)
at /usr/include/c++/5/functional:1520
#11 0x000000000063b0cc in std::thread::_Impl<std::_Bind_simple<std::_Mem_fn<void (ZmqWorker::)()> (ZmqWorker)> >::_M_run()
(this=0x2363f00) at /usr/include/c++/5/thread:115
#12 0x00007ff8f7066c80 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#13 0x00007ff8f92da6ba in start_thread (arg=0x7ff5e8000700) at pthread_create.c:333
#14 0x00007ff8f65aa41d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109
(gdb)

Environment

ubuntu 16.04
libzmq 4.3.0

Minimal test code / Steps to reproduce the issue

The problem was discovered during a stress test

I'd like to know what factors contributed to the error，thank you !!

[bluca]

Are sockets being used from multiple threads?

[wushuangge]

Are sockets being used from multiple threads?
yes,
sockets are used from multiple threads

[wushuangge]

Are sockets being used from multiple threads?

But I've locked each socket

[bluca]

As the docs say, sockets are not thread safe. Locks on the application side are not enough. Each socket must be created, used and closed from a single thread.