Re: Required Metrics

["Ken Garlington" <Ken.Garlington@computer.org>]

Having gone back and read the thread on this subject from May 1999, the
closest thing I found to an answer to my question was, essentially, "It's
not practical for a vendor to document the required metrics if it relies on
an underlying operating system." I'm not sure I buy this in all cases --
what if the OS vendor provides sufficient information on their thread
support, for example? -- but let's assume it's a reasonable caveat. Given
this, then:

1. Why wouldn't this be the response given in the documentation; i.e. "This
implementation conforms to the Real-Time Annex, except for the documentation
of metrics, which is not practical"? (Better yet, why didn't anyone put this
in the ARM to begin with, or write an interpretation after the fact?)

2. What would this mean for an implementation that didn't use an operating
system; e.g. GNORT? (By the way, if it wasn't obvious, this isn't a rant
about GNAT. It's a question about the meaning -- or maybe, lack of
meaning -- of the standard...)

I'm starting to wonder about the responses to this question (and the lack
thereof). Are there other requirements in the ARM that are optional in
practice? Is it a general rule that if it's not tested in the validation
suite, a vendor can decline to implement the requirement but still be
considered conforming? If so, what does this mean with respect to the
assumed benefits of standardization?

"Hey, this compiler doesn't implement tasking, but it says it conforms to
the ARM!"
"Well, you can always call the pthreads package and implement it yourself.
Call the vendor, they'll provide assistance. Alternately, you can ask for
tasking support in a later release."