Use of EAGAIN vs. ETIMEDOUT

[sigiesec]

Almost all libzmq public API functions that work with a timeout return EAGAIN when the timeout has been reached. However, zmq_poller_wait, zmq_poller_wait_all and zmq_poller_poll return ETIMEDOUT instead.

At least under Windows ETIMEDOUT resp. WSAETIMEDOUT is used only to indicate connection timeouts, which is also an argument for EAGAIN.

Is there a specific reason for using ETIMEDOUT? Otherwise I would change these uses to EAGAIN as well.

[bluca]

This is one for @somdoron I think :-)

[somdoron]

Good point. I think only those method explicitly accept timeout as parameter while the rest don't.

[somdoron]

We can consider the change, however the API already in use (although marked as draft) so people might hate us.

[sigiesec]

Eh... if we cannot change it then why is it marked as draft?

Apart from that, I think it is a good thing that zmq_poller_* is still marked as draft, since e.g. #2623 is still open, which might involve more significant changes than aligning the error codes.

There is not even documentation for zmq_poller_* yet...

[bluca]

Yeah I agree, if it's marked as DRAFT it's fair game, it's documented well enough (I think?) why that system exists and what it implies to enable those APIs

[bluca]

For the docs I opened this to track it: #2188

[somdoron]

PR is of coursed welcomed

[sigiesec]

@somdoron I already fixed it, will send a PR tonight.

I wanted to "assign" the issue (and others) to myself, but apparently I cannot do that. Isn't it sufficient that I am a "member"?

[paddor]

The change makes sense. Not hating anyone, barely annoyed. But no hate. :) It's marked as draft, after all.