[zeromq-dev] CZMQ question re: use of zpoller

[Brett Viren]

Hi again,

Johnny Depp <sdusa at hotmail.com> writes:

> Yes, the pull socket is in only one thread

Okay.  Then I guess something else is going on.

> However, I switched to sending chunks of memory using zsock_brecv and
> zsock_bsend. And I am back to no reaction. At all.

Maybe no longer relevant but just one multi-thread related comment:
these "b" variants make use of ZeroMQ's "more" feature.  Each CZMQ frame
is passed to/from libzmq one at a time so state is kept behind the
scenes.  This is one particular case I've been cautioned (when I went
down the road of using thread-spanning sockets) will lead to problems.

> But I will recompile the library with the SERVER/CLIENT draft and see
> if that works better.

This will not be needed if indeed your sockets live entirely in one
thread.

But, if you do go to these thread-safe sockets one restriction we must
live with is that all messages will need to be "single-part".  So, the
"b" send/recv variants including "picture" messages of CZMQ won't work.

However, any multi-part zmsg_t can be encoded into a single-part
zframe_t using CZMQ zmsg_encode() just prior to a send and returned to a
multi-part zmsg_t with a zmsg_decode() just after a recv.

-Brett.
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