3-rd round RFR (S) 8008678: JSR 292: constant pool reconstitution must support pseudo strings

[serguei.spitsyn at oracle.com]

On 1/16/15 3:32 PM, John Rose wrote:
> On Jan 16, 2015, at 3:03 PM, Coleen Phillimore 
> <coleen.phillimore at oracle.com <mailto:coleen.phillimore at oracle.com>> 
> wrote:
>>
>> I was sort of wondering about this along the same lines.  You're 
>> setting the second bit, right? :)
>
> That sounds good, much better than the string prefix hack.
>
> Parsing the string would introduce too much coupling between the JVM 
> and random details of the JDK.
>
> I also suggested to Serguei that redefinition of patched classes is 
> not going to happen, since they are not user-visible.  So all of the 
> "EMCP" logic can punt on pseudo-strings, one way or another, if it 
> needs to.
>
> BTW, since patched classes are always anonymous classes, you can't 
> even get to them, unless you dig them out some private place like a 
> lambda form.

Anonymous classes can be noticed by agents with the CL or CFLH events.
Then nothing stops agents from redefining or re-transforming anonymous 
classes.

>
> Reconstitution is also a lost cause, since the patches will be 
> dropped, but I see how that might be something you might possibly run 
> into, as a stress test or some sort of debugger display.

I've filed a new bug to track this issue as we early agreed with Coleen:
   https://bugs.openjdk.java.net/browse/JDK-8069233

Fill free to update it if necessary.


Thanks,
Serguei

>
> — John

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