Re: KITTEN: IETF 75 - 76

[Jeffrey Hutzelman <jhutz at cmu.edu>]

--On Wednesday, September 02, 2009 09:12:00 PM -0400 Michael B Allen 
<miallen at ioplex.com> wrote:

> I think you're exaggerating, if not misrepresenting, the detractions of
> the NOWAIT flag technique.

No, he's not.  Nonblocking API's are OK, but there has to be a way to tell 
when it's time to try the call again, and neither periodic polling nor 
busy-wait is acceptable.  The GSS-API MUST NOT force such wasteful and 
performance-killing techniques on applications.

Really, I think we have three options here:

1) Assume POSIX threads(*).
2) Assume POSIX threads(*), but allow the existence of an implementation
  dependent means of indicating use of some other threading model.
3) Recognize that there is no sane way to provide an portable async API
  without either a portable threading model or a portable event model,
  and give up.  Applications which want to call the GSS-API in an
  asynchronous manner can simulate it by running the GSS-API call in
  its own thread (under a platform-specific thread model).

(*) This means "you can't have this API unless you have threads".
Unfortunately, it also means we're in the unenviable position of pushing
an API which requires the use of threads but is not itself MT-safe.

-- Jeff