[armedbear-devel] Forking new ABCL processes cheaply (was Re: asdf and windows vs unix on abcl)

[Alessio Stalla]

On Mon, Oct 24, 2011 at 7:39 PM, Mark Evenson <evenson.not.org at gmail.com> wrote:
>
> On Oct 24, 2011, at 19:21 , Faré wrote:
> […]
>> Can ABCL somehow start a fresh image for cheap in the same Java heap,
>> or even better, fork a CL image within the same Java heap?
>> That would make ABCL much more useful as an XCVB backend.
>
> No, the usual JVM implementations don't have this sort of capability.
> If our abstractions of specials, streams, etc. are managed correctly,
> we should be able to run threads for you quite cheaply.  I'm working
> on a wrapping of the JVM Executor service.  Stay tuned.

I believe Faré's reason for starting a new image is to have it clean
of any side-effects of previous compilations. Strictly speaking, this
would only be possible if the JVM supported fork() or save-image, but
unfortunately it doesn't and will probably never do. However, I have
an idea for a compromise that would not get you a truly fresh new
image, but could nevertheless create a new environment clean enough
for most use cases. I don't have the time to go into details now, but
that's definitely something I've been wanting to experiment with for
some time.

Alessio