Re: libpq: Which functions may hang due to network issues?

On 5. Dec 2021, at 21:32, Daniel Frey <d(dot)frey(at)gmx(dot)de> wrote:
>
>> On 5. Dec 2021, at 17:01, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>
>> Daniel Frey <d(dot)frey(at)gmx(dot)de> writes:
>>> With all that said, I think that PostgreSQL/libpq should have a clear, documented way to get rid of a connection that is guaranteed to not hang. It has something similar for almost all other methods like opening connections, sending request, retrieving results. Why stop there?
>>
>> AFAICS, PQfinish() already acts that way, at least up to the same level of
>> guarantee as you have for "all other methods". That is, if you previously
>> set the connection into nonblock mode, it won't block.

One more question about this: What is the purpose of *not* using nonblocking mode with PQfinish()? Is there any benefit to the user in waiting for something? Or could it make sense for PQfinish() to always use nonblocking mode internally?