[nanomsg] Re: [PATCH] Terminate astream if initializing usock failed
- From: Nir Soffer <nirsof@xxxxxxxxx>
- To: nanomsg@xxxxxxxxxxxxx
- Date: Tue, 12 Mar 2013 15:28:21 +0200
On Tue, Mar 12, 2013 at 1:09 PM, Martin Sustrik <sustrik@xxxxxxxxxx> wrote:
> On 2013-03-12 11:49, Nir Soffer wrote:
>
>> On Tue, Mar 12, 2013 at 12:09 PM, Martin Sustrik <sustrik@xxxxxxxxxx>
>> wrote:
>>
>> On 2013-03-12 10:59, Nir Soffer wrote:
>>>
>>> On OS X the scenario is this:
>>>
>>>>
>>>> 1. client connects and close the socket
>>>> 2. server accept a new socket
>>>> 3. server tune the socket
>>>> 4. setsockopt fail with EINVAL (looks like a bug in OS X, as the value
>>>> is
>>>> valid (e.g. 128K receive buffer)
>>>>
>>>>
>>> Yuck. That's an ugly behaviour. Anyway, what if we simply ignored the
>>> EINVAL error from all those setsockopts, when on OSX?
>>>
>>
>>
>> What will happen if we fail to make the socket non-blocking, and then we
>> try to initialize the stream with a blocking socket?
>>
>> I think that failing fast is better in most cases. What I don't like about
>> this patch is that we cannot detect a bug in the library. For example, if
>> we change the code to set a (real) invalid value, we will simply fail to
>> handle all connections, instead of asserting.
>>
>
> Yeah. I hate that we can't distinguish real "errorneous value" problem
> (nanomsg should assert) from "peer disconnected" problem (nanomsg should
> close the socket in decent manner).
>
> Anyway, given that we are not able to distinguish between the two, I think
> that only option is to assume that there's no bug in the related library
> code and consider the error to mean "peer disconnected".
>
>
> What if we check EINVAL, then fail with -EINVAL on OS X (and other
>> platform
>> that show this error), and assert on Linux?
>>
>
> AFAICS it's the same as ignoring the error on OSX.
But on other platforms - assuming that it never happens there, we can now
detect a bug in the library.
> The assumption is that the peer have disconnected. If we ignore the error
> next send/recv call on socket fails and socket will be shut down. If we
> return -EINVAL, the socket will be shut down. Same thing.
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