Status of Anno Class loader with constant patches?

Mark Roos mroos at roos.com
Thu Jan 6 08:42:46 PST 2011


Thanks to all for the suggestions on providing live constants to a method.

I must admit that I was impressed with how the constant patch approach 
worked.
As my constants are defined using an utf8 string it was easy to use some 
unused
constant type tags to mark my constants.  The loader then searched for 
them,
created a patch from the string and then converted the tag to the utf8 
tag.
Load the class and done.  Very nice.

But I was worried that this was not mainstream.  So Remi's inputs were 
good.
My first attempt was ugly.  Ugly in that the constant pool went wild.  For 
each
constant ( and a method could have a hundred or so ) I needed an 
invokeDynamic,
a bootstrap table entry and my constant string.  After thinking a bit ( 
always a 
good thing to try) I realized that the name part of the invoke dynamic 
could
carry the constant.  So now I have a shared bootstrap, and a per constant 
invokeDynamic,
nameAndType and constant.

Not as pretty as the pool patching but good enough.  My only concern will 
be how well
it gets optimized and that I will leave to the experts.

Now on to airity and the unfortunate issue that my stack order is opposite 
that of Java
('this' is at the end not the beginning)

regards
mark
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