So many cool things!
We cannot even imagine at this point what all these little conceptual
things will bring in downstream projects. This is amazing.
well there are large conceptual things made looking like little
conceptual things :)
This is the trick but yes we know were we go and I love it.
Thanks a lot,
Doru
On Fri, Feb 27, 2015 at 12:07 AM, Marcus Denker
<[email protected] <mailto:[email protected]>> wrote:
Hi,
In 40516 there is now a strange, but rather powerful mechanism for
CompiledMethod: the Twin.
What does that do?
you can call on a method #createTwin
(ReflectivityExamples>>#exampleMethod) createTwin.
after this, the CompiledMethod has a high-level representation
(the AST) attached that itself references the CompiledMethod
(they form a twin).
(ReflectivityExamples>>#exampleMethod) reflectiveMethod
The fun thing is now that one can install either in the class.
Call #invalidate to make sure the reflective method is installed.
ReflectiveMethod implements #run:with:in: which calls a
compilation hook (too re-create from the AST) and then installs
that in the
method dict and then executes the method:
(ReflectivityExamples>>#exampleMethod) createTwin.
(ReflectivityExamples>>#exampleMethod) invalidate.
self assert: (ReflectivityExamples>>#exampleMethod) class
= ReflectiveMethod.
self assert: ReflectivityExamples new exampleMethod = 5.
self assert: (ReflectivityExamples>>#exampleMethod) class
= CompiledMethod.
Which means that this gives us an in-image, on-demand JIT compiler
AST->Bytecode. In 50 lines of code.
e.g. try on Morph:
Morph methods do: #createTwin.
Morph methods do: #invalidate.
Counting which twin is installed shows us the working set of Morph:
(Morph methods select: [ :each | each class = CompiledMethod ]) size
some 330 method out of nearly 900….
So what can one do with this? In essence this turns the AST into a
reflective representation for Methods
(if you care to set up twin creation + invalidation correctly).
What will this allow us to do? stay tuned...
Marcus
--
www.tudorgirba.com <http://www.tudorgirba.com>
"Every thing has its own flow"
