[zeromq-dev] Handling errors from OpenPGM call pgm_recv() and friends

[Steven McCoy]

2009/12/22 Martin Sustrik <sustrik at 250bpm.com>

> Hi Steven,
>
> I've modified the code in the following way:
>
>    //  Bind a transport to the specified network devices.
>    if (!pgm_transport_bind (transport, &pgm_error)) {
>        if (pgm_error->code == PGM_IF_ERROR_INVAL ||
>              pgm_error->code == PGM_IF_ERROR_XDEV ||
>              pgm_error->code == PGM_IF_ERROR_NODEV ||
>              pgm_error->code == PGM_IF_ERROR_NOTUNIQ ||
>              pgm_error->code == PGM_IF_ERROR_ADDRFAMILY ||
>              pgm_error->code == PGM_IF_ERROR_FAMILY ||
>              pgm_error->code == PGM_IF_ERROR_NODATA ||
>              pgm_error->code == PGM_IF_ERROR_NONAME ||
>              pgm_error->code == PGM_IF_ERROR_SERVICE) {
>            g_error_free (pgm_error);
>            errno = EINVAL;
>            return -1;
>        }
>
>        zmq_assert (false);
>    }
>
> The idea is that the problems caused by user are reported as EINVAL. If
> there'll be need for more fine grained errors we can then map OpenPGM errors
> to errnos, as required by concrete scenarios.
>
> The errors not caused by the user result in an assertion. If these occur in
> practice, we can either add the code to handle the error decently (say by
> restarting the transport) or return adequate errno.
>
> Does the code look right? I was not sure about the "domain" in the error.
>
>
The domains allow for separate namespaces for error codes, which means
PGM_IF_ERROR_INVAL has the same code value as  PGM_TRANSPORT_ERROR_FAULT,
meaning you will want to change the code to something like this,

   if (!pgm_transport_bind (transport, &pgm_error)) {
       if (pgm_error->domain == PGM_IF_ERROR &&
            (pgm_error->code == PGM_IF_ERROR_INVAL ||
             pgm_error->code == PGM_IF_ERROR_XDEV ||
             pgm_error->code == PGM_IF_ERROR_NODEV ||
             pgm_error->code == PGM_IF_ERROR_NOTUNIQ ||
             pgm_error->code == PGM_IF_ERROR_ADDRFAMILY ||
             pgm_error->code == PGM_IF_ERROR_FAMILY ||
             pgm_error->code == PGM_IF_ERROR_NODATA ||
             pgm_error->code == PGM_IF_ERROR_NONAME ||
             pgm_error->code == PGM_IF_ERROR_SERVICE)) {
           g_error_free (pgm_error);
           errno = EINVAL;
           return -1;
       }

       zmq_assert (false);
   }

-- 
Steve-o
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