Continuation.yield limitations

[Alan Bateman]

On 09/09/2019 09:10, Andrew Haley wrote:
> :
> I think there is. It would take work and co-operation with C compiler
> people. The main reason we can't touch the native layer from Java is
> that we tell ourselves that it's something we must not touch: it's a
> black box. But these days it's all either free software or it's from
> people (like Microsoft) we can talk to. The old days of dozens of C
> compilers have gone.
One other thing to say about this limitation is that it's unlikely to 
arise too often. When we started out the two native frames that caused 
issues were AccessController.doPrivileged, and during warm up, 
Method.invoke. The former is no longer an issue as it has been 
re-implemented in Java so the code in the VM to setup the privileged 
stack has gone away. For the latter, the temporary workaround is to 
generate the method accessors to avoid core reflection calling methods 
(or constructors) through the VM when initially used. We expect this 
will eventually be replaced to use method handles. So for for now at 
least, I don't think the limitation is a major concern.

-Alan