[Seaside] Porting to ST/X

Keith Hodges Keith.Hodges@Cheerful.com
Tue, 12 Mar 2002 11:59:06 +0000

Avi wrote:

> Hope this helps.  I should point out that I did spend some time hacking
> around in ST/X trying to get this stuff working, but to no avail...
> hopefully you'll have better luck.

Now for the bad news, I contacted claus about this and this is his

Claus Gittinger wrote:

with the current scheme (mapping contexts onto C-calling frames),
there is no solution to the continuations problem - it is simply
not possible right now, to return twice from a context
(it does not help to modify the sender of a context to trick it).
The reason is that the VM (currently) does not update a machine
stack context from a changed Context-OOP.
The only supported operations on contexts are returning from it
and restarting it (which is done by setjmp/longjmp'ing on the C-level).
Sorry about this
(I may care for this in my next VM - but that does not help now).

Keith writes:

My thoughts -- I was wondering whether, rather than returning from a
twice,  we could try and  use the  QuerySignal (resumable non-error
exception) mechanism to return processing to the calling context, and

any thoughts