Classpath and java.util.concurrent

[Tom Tromey]

Most of the reference implementation of java.util.concurrent is in the
public domain.  I took a quick look at it last night.  I thought I'd
post the results here and see what people think.

The public domain bits are about 30 KLOC, mostly in
java.util.concurrent.  I had to delete a couple of Sun-derived
classes, which we'd have to replace.  This didn't look to be a big
problem, mostly it was a class derived from ArrayList.  It relies on a
few 1.5 APIs that we don't have yet... no big deal.

The code uses generics.

It calls into a sun.* class for unsafe low-level operations.  This we
could refactor to a classpath-style VM class.  There are a couple of
other sun.* dependencies which can be handled similarly.

The code from the upstream cvs repository already has all the 1.6
additions in the source.  I think we probably should remove this.


Managing imports here looks like a pain.  We'd like the latest code,
to pick up bug fixes, but IMO we want to avoid the 1.6 additions until
1.6 is really released.  We also want to refactor parts of the code a
little to avoid Sun-isms.

One idea would be to check it in on a pristine branch (like cvs
import, but we probably don't want to use that in this case) and then
merge it over the generics branch and clean it up there.


I would suggest putting the code in external/, e.g., external/jsr166.

I think it would make sense to import it and get it on the branch
before hooking it into the build.  That way, fixing it up to work in
Classpath won't have to be a solo effort.

Comments?

Tom