[nanomsg] nn_close() of nanomsg socket hangs forever
- From: "Jason E. Aten" <j.e.aten@xxxxxxxxx>
- To: nanomsg <nanomsg@xxxxxxxxxxxxx>
- Date: Sat, 31 Jan 2015 18:38:29 -0800
In my application, this doesn't happen for a while, but then after a while,
the server doing an nn_close() on a nanomsg socket hangs forever.
I read in close 2 man page:
When dealing with sockets, you have to be sure that there is no
*recv*(2) still blocking on it on
another thread, otherwise it might block forever, since no more
messages will be sent via the
socket. Be sure to use *shutdown*(2) to shut down all parts the
connection before closing the
socket.
Moreover I see this example discussion [the answer by Joseph Quinsey
<http://stackoverflow.com/users/318716/joseph-quinsey>] of how to properly
close a socket:
http://stackoverflow.com/questions/12730477/close-is-not-closing-socket-properly
Mr. Quinsey suggests that there are three (3) steps needed to successfully
close without hanging:
a) getsockopt(fd, SOL_SOCKET, SO_ERROR, (char *)&err, &len)); // to clear
any error on the socket
b) shutdown(fd, SHUT_RDWR); // to terminate reliable delivery
c) close(fd); // finally
I don't see nanomsg doing a) or b), so I tend to think this is a bug in the
nn_close() implimentation, and these two steps should be added.
Thoughts?
Thanks!
- Jason
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