[zeromq-dev] Race condition in zmq_engine_t::out_event

[Christian Gudrian]

Hello!

The method zmq_engine_t::out_event gets called concurrently by (at 
least) two worker threads during test_shutdown_stress. If there are data 
to be written, they get written twice and as a consequence the outsize 
member gets decremented too often resulting in an integer underflow. 
That in turn triggers subsequent errors, of course.

Shouldn't the out_event method be synchronized then?

Christian