问题
I'd like to fan out messages and be sure that any connected socket has received them, if present.
So is there a pattern to achieve the following:
- PUB socket shall block on watermark if there is one or more SUB connected, i.e. all of the SUB sockets have received the message.
- PUB socket shall drop on watermark if there is no SUB connected.
I use nzmqt within Qt5 on OSX/Linux, if this is helpful or the mentioned problem could be solved in this special case.
来源：https://stackoverflow.com/questions/15059193/zeromq-pattern-pub-sub-with-guaranteed-delivery