> De: "Karen Kinnear" <karen.kinn...@oracle.com> > À: "Remi Forax" <fo...@univ-mlv.fr> > Cc: "John Rose" <john.r.r...@oracle.com>, "valhalla-spec-experts" > <valhalla-spec-experts@openjdk.java.net> > Envoyé: Jeudi 31 Janvier 2019 21:36:09 > Objet: Re: An example of substituability test that is recursive
> Option #1 was what I was suggesting in the meeting two weeks ago - if this > starts > to recurse too deeply, create a worklist - which should give you the same > result. > If you switch to .Equals - you might get a different result … yes, you are right, i did not understand what you mean by "expected behavior", my bad on that. > thanks, > Karen regards, Rémi >> On Jan 31, 2019, at 1:46 PM, [ mailto:fo...@univ-mlv.fr | fo...@univ-mlv.fr ] >> wrote: >>> De: "John Rose" < [ mailto:john.r.r...@oracle.com | john.r.r...@oracle.com >>> ] > >>> À: "Remi Forax" < [ mailto:fo...@univ-mlv.fr | fo...@univ-mlv.fr ] > >>> Cc: "Karen Kinnear" < [ mailto:karen.kinn...@oracle.com | >>> karen.kinn...@oracle.com ] >, "valhalla-spec-experts" < [ >>> mailto:valhalla-spec-experts@openjdk.java.net | >>> valhalla-spec-experts@openjdk.java.net ] > >>> Envoyé: Jeudi 31 Janvier 2019 19:05:33 >>> Objet: Re: An example of substituability test that is recursive >>> On Jan 31, 2019, at 6:34 AM, [ mailto:fo...@univ-mlv.fr | fo...@univ-mlv.fr >>> ] >>> wrote: >>>> The other solution is to say that == should do an upcall to equals (after >>>> the >>>> null checking and the class checking), if equals throw a StackOverflow, >>>> it's >>>> the expected behavior because the user is in control of that behavior. >>> What you are doing here, I think, is exposing a requirement >>> that we *don't* use the control stack for recursion on subst. >>> testing (or hashing). That's a reasonable requirement. >>> It leads to a worklist algorithm for doing this tricky thing, >>> just like we had to do many times in the JIT. >> IMO that the other solution, >> solution 1: you use a worklist (and also perhaps a marking algorithm to >> avoid to >> crawle the DAG) >> solution 2: you claim it's too complex and you just let the user deal with >> it by >> calling equals() (and provide a way for a user to call the default subst). >> Rémi
