Task #4636
closed
Modify docs to show producers unregistering prefixes to shut down faces
100%
Description
As discussed at the NDN Platform Call on June 11, the ndn-cxx documentation, including examples, needs to be modified so that producers are shown shutting down faces by unregistering all prefixes, instead of calling Face::shutdown(). This will ensure that the last sent Data packet is actually transmitted before the face shuts down.
Updated by Eric Newberry over 6 years ago
- Related to Task #4642: Update producers across platform to unregister prefixes instead of shutting down face added
Updated by Eric Newberry over 6 years ago
The existing producer example in ndn-cxx doesn't shut down its face, except in response to a prefix registration error, where Face::unsetInterestFilter() would be of no use. Does it need to be modified at all?
Also, I can't find any specific references to Face::shutdown() in the ndn-cxx documentation. Even so, we should probably add something about the proper way to shut down a face on a producer.
Updated by Davide Pesavento over 6 years ago
Eric Newberry wrote:
Also, I can't find any specific references to
Face::shutdown()in the ndn-cxx documentation.
You mean besides the doxygen[1]? What other doc do we have?
[1] http://named-data.net/doc/ndn-cxx/current/doxygen/d9/d55/classndn_1_1Face.html#a94cece651790f2b3e140ed157667587e
Even so, we should probably add something about the proper way to shut down a face on a producer.
Yes, we should.
Updated by Eric Newberry over 6 years ago
- Status changed from New to Code review
- % Done changed from 0 to 100
Updated by Junxiao Shi over 6 years ago
“Waiting for processEvents() to exit” isn’t a proper solution when multiple faces are tied to the same io_service. Is there another way?
I’m suspecting the m_transport.close() line in Face::asyncShutdown(). StreamTransportImpl::close() clears the transmission queue, and packets could be lost there.
Updated by Eric Newberry over 6 years ago
Junxiao Shi wrote:
“Waiting for processEvents() to exit” isn’t a proper solution when multiple faces are tied to the same io_service. Is there another way?
I’m suspecting the m_transport.close() line in Face::asyncShutdown(). StreamTransportImpl::close() clears the transmission queue, and packets could be lost there.
So do we need to modify the code to prevent this issue, instead of just shifting to unsetInterestFilter?
Updated by Eric Newberry over 6 years ago
- Status changed from Code review to Closed
The relevant change was merged.
@Junxiao, feel free to move this to "Feedback" if you think more discussion of note 6 is warranted.
Updated by Davide Pesavento over 6 years ago
Junxiao Shi wrote:
“Waiting for processEvents() to exit” isn’t a proper solution when multiple faces are tied to the same io_service.
Is there a use case for employing multiple Face instances in the same application? If an application really wants to do what you're saying, it should call run()/stop()/reset()/etc.. on the io_service directly, and not use Face::processEvents() and shutdown().