Missing break into server code examples?

Hello fellow coders!

I'm new to GnuTLS and I'm studying examples provided by documentation.
I noticed in most server examples there is no break after

gnutls_record_send() (or only if error is triggered).

I don't know if it's intentional, but while testing  example given in 
7.2.1 titled "Echo server with X.509 authentication", it appears that 
code hang when calling

gnutls_record_recv()

after echoing back data. Firefox is loading indefinitely as well as curl 
which never complete.

The only way I found to have something right is to set a break after 
gnutls_record_send(). By doing that I'm able to complete the loading of 
the server response with a browser or a command line tool.

Is there something I don't understand about this?

Best regards,
Denis