cppzmq | Header-only C++ binding for libzmq | Natural Language Processing library

It seems to me that the first problem is with the order of these lines:

Your Makefile defines:

The answer is that it can't be done using cppzmq facilities, but you can write your own implementation of the poller_t class, because it's FOSS, and just extend it with the additional features that you need. It works a charm.

The starting point is to copy your version of the implementation of the poller_t template class into a new header file, and then just add the following in the appropriate locations. You may need to make slight modifications to suit, depending on how the cppzmq library evolves. Use using declarations to bring the necessary types into your namespace.

Use zmq_msg_init_data

http://api.zeromq.org/master:zmq-msg-init-data

You can provide the memory pointer/size of your already allocated memory and zeromq will take ownership (skipping the extra allocation). Once its been processed and is no longer needed it will call the associated free function where your own code can clean up.

I have used this approach in the past with a memory pool/ circular buffer and it worked well.

It is important to distinguish between the recipe name cppzmq and the provided packages of the recipe. A single recipe can provide several packages (, -dev, -staticdev etc.).

With IMAGE_INSTALL you define which packages are included in the image.

Looking at the cppzmq recipe you can see that it only provides PACKAGES = "${PN}-dev".

Hence you should use IMAGE_INSTALL_append = " cppzmq-dev"

The main idea about ROUTER/DEALER pattern is that it is an asynchronous generalisation of REPLY/REQUEST. Yet you are trying to reverse the sockets in your pattern, discovering it doesn't fit and contorting the code to try and make it fit. Don't do that.

What you need to do is "go with the flow". In the simple method, for which examples exist, the DEALER should send the first message. The ROUTER then responds to that.

The next level is for the DEALER to identify itself in its startup message. The ROUTER can then give a specific response to that DEALER.

At the next level you can go truly asynchronous. The ROUTER can take a copy of each DEALER's identification message, and use the message copies to send asynchronous messages to any DEALER at any time. One copy of the identification message would have the "PEER2" frame appended to it and sent to the DEALER. This works because the copies of the messages include the routing frames. Ideally, you would also strip the 'message' frames, to leave only the routing frames in the copy.

Caveat - I don't use cppzmq, I use CZMQ. I can say that using CZMQ this sort of frame manipulation is very easy.