Tom Lane <tgl@sss.pgh.pa.us> writes:
> Tomas Berndtsson <tomas@nocrew.org> writes:
> > After it tries again, it always gets error from recv() for some reason
> > that I don't know. I also don't understand why errno is set to ENOTTY
> > at this point, that makes no sense at all.
>
> Are you sure it is set? Try setting errno=0 just before recv() (inside
> the retry loop). Maybe recv() is neglecting to set it in this case.
Indeed you were right in this. But, if I added -D_REENTRANT to the
Makefile for libpq, it started to set it. If libpq should be thread
safe, I believe it should be compiled with -D_REENTRANT.
When I did this, recv still returns error, but now sets errno to
EAGAIN, so pqReadData() returns 1, giving the same result as removing
the if-statement that does the try again thing.
> > By skipping the trying again if-statement, pqReadData() will always
> > return proper data, and let the calling function deal with the fact
> > that there is more data to be read.
>
> I have no confidence in this. If the calling function comes back for
> more data, why wouldn't the recv() fail the same way? A few more
> instructions in between shouldn't change its behavior, one would think.
No, I agree it sounds strange. I still haven't figured out why recv
fails after the goto, but not when calling the function again.
Tomas