Re: new compiler warnings

On Tue, Oct 18, 2011 at 12:26 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Tue, Oct 18, 2011 at 10:06 AM, Peter Eisentraut <peter_e(at)gmx(dot)net> wrote:
>>> No, I believe we are OK everywhere else.  We are only ignoring the
>>> result in cases where we are trying to report errors in the first place.
>
>> The relevant code is:
>
>>     while (len > PIPE_MAX_PAYLOAD)
>>     {
>>         p.proto.is_last = (dest == LOG_DESTINATION_CSVLOG ? 'F' : 'f');
>>         p.proto.len = PIPE_MAX_PAYLOAD;
>>         memcpy(p.proto.data, data, PIPE_MAX_PAYLOAD);
>>         write(fd, &p, PIPE_HEADER_SIZE + PIPE_MAX_PAYLOAD);
>>         data += PIPE_MAX_PAYLOAD;
>>         len -= PIPE_MAX_PAYLOAD;
>>     }
>
>> Which it seems to me we could change by doing rc = write().  Then if
>> rc <= 0, we bail out.  If not, we add and subtract rc, rather than
>> PIPE_MAX_PAYLOAD.  That would be barely more code, probably safer, and
>> would silence the warning.
>
> And it would break the code.  The whole point here is that the message
> must be sent indivisibly.

How is that different than the chunking that the while loop is already doing?

--
Robert Haas
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