On Thu, Jan 16, 2020 at 10:19:52AM -0700, Raymond, David wrote:
> Thanks, that is helpful.
>
> It is now clear to me that the default on OpenBSD for SSIZE_MAX is
> 2^31 - 1 or greater. However, I still run into problems on writes to
> a TCP/IP socket with sizes exceeding something like 32000 bytes
> (probably 2^15 -1).
>
> Is it possible that TCP sockets have a smaller SSIZE_MAX or could this
> be a bug? I am handling partial reads and writes correctly as far as
> I can see. Chopping big writes into chunks smaller than 32000 seems
> to solve the problem.
You need to tell more details. what errno? mayeb a ktrace? Show the code?
-Otto
>
> Dave
>
> On 1/16/20, Martin Wanvik <[email protected]> wrote:
> > tor. 16. jan. 2020 kl. 14:52 skrev Raymond, David <[email protected]>:
> >>
> >> Hmm....
> >>
> >> Thought I found a 2^15 -1 version of SSIZE_MAX in the includes, but I
> >> guess I was mistaken.
> >
> > Not necessarily. What you have probably seen is _POSIX_SSIZE_MAX
> > (which is almost literally
> > what you wrote in your first post), defined in limits.h to be 32767
> > (2^15 - 1). But that
> > specifies the minimum value that SSIZE_MAX can have and still conform
> > to the POSIX standard.
> > So the actual SSIZE_MAX may well be (and usually is) much bigger, as
> > others have pointed out.
> >
> >> The real issue is whether doing write(2) to a TCP/IP socket bigger
> >> than 2^15 - 1 bytes causes problems. I am not very experienced in
> >> this area.
> >
> >
>
>
> --
> David J. Raymond
> [email protected]
> http://physics.nmt.edu/~raymond
>
