[gclist] ref-counting performance cost

[Greg Hudson]

> For what it's worth, Inferno (which is, or was, freely available)

I don't think Inferno has ever been freely available.  At the moment
it appears you can get a source code license for $300, or $150 if
you're in academia.

Plan 9 is now freely available (with some obnoxious license terms),
but that's something completely different and is not really
interesting to this thread.

> The job of a PhD is to produce *knowledge*.

But Ph.D. theses are usually extremely focused.  Restricting a study
of garbage collection performance to one language seems reasonable,
although I'm no Ph.D. advisor.

> Let's suppose you did come up with a great new GC method for Java
> (and the full Java sources are or were available for academic
> research, so you could work with "the real thing").  There's still
> no reason to expect that anyone would ever adopt it.

You seem to be very focused on treating languages as implementations
rather than specifications, a world view which works well for Perl or
Erlang or Python but not as well for Java or C.  There are multiple
implementations of Java, some of which are freely available.  Unless
interest in Java wanes over time (always a possibility), a superior
garbage collection method for Java would always be interesting to a
new implementor, to the gcj team, etc..