Can I use zmq_send() and zmq_recv() in different threads?

I know ZMQ guide says that the following is not thread-safe.

But I want use one thread receive data:zmq_poll() wait data come, then use zmq_recv() receive data; use another thread send data: zmq_send()

I want to know is this a right way to use ZMQ?In fact I have try it. The program core dump when call zmq_poll() once, but it only happen once and can't reappear.