Thank you very much, Sean. I suggest you work with Henrik and Alex and I on this as well (possibly off-line, outside of this forum.)
In case it helps, here is what I tried to do, and what I think I discovered. Please forgive me if I am inconsistent; I clearly have been confused on some of these points. This has been a learning process for me; I am writing this only in hopes of saving you time. 1) It so happens that some of the elephant objects do exactly what we are discussing --- that is, they do special initialization in "shared-initialize". 2) The test always worked for me (the first time they were run.) When I ran them the second time, I had failures. I am not 100% sure this had to do with your patch or not...it is possible that I have an SBCL error or some other problem. 3) It seems straightforward to rewrite the "make-instance" and "shared-initialize" methods to separate things into an auxiliary initialization function called by "make-instance" and "recreate-instance-using-class". However, this is tricky when it comes to pm-indexed-btree, the classes that implement the secondary cursors. There may be some danger that "persistent-slot-writer" puts us in a foward-reference problem: You're trying to initialize the class but the initialization code assumes that make-instance has already been called, but something it requires is not initialized. I think if I clear headed-person understood exactly the object creation protocol, they could probably refactor it out successfully. 4) Given the multiple inheritance of "pm-indexed-btree" (a subclass of "indexed-btree" and "pm-btree", it was not clear to me exactly what order the MOP stuff got called. It is possible that some subtle aspects of this are even lisp-dependent. So, in summary, what I tried to do was to rewrite the files in src/db-postmodern so that they were properly initialized by recreate-instance-using-class. I was never able to get this to work, and whether that is due to my own confusion (I have bronchitis at the moment) or some weirdness in SBCL I can't say. I suggest you and Ian come up with the "reconstitution" protocol which he has proposed. I'm happy to work to on this, but I don't feel that I understand common usage of LISP --- all of my coding has in LISP has been in complete isolation outside of this list. On Tue, 2008-01-08 at 17:45 +0000, Sean Ross wrote: > Hi all, > > I'm sorry to hear that my patch caused so many issues with postmodern > and I'm quite keen to investigate the cause of this. I'll be > installing setting up the postmodern backend and seeing if I can track > down the causes of these problems. > > As to where to go from here I do agree with robert on this and that it > is nice to have the seperation between the creation and restoration of > instances although I think this needs to be done with a well thought > out protocol. > > cheers, > sean. > _______________________________________________ > elephant-devel site list > elephant-devel@common-lisp.net > http://common-lisp.net/mailman/listinfo/elephant-devel _______________________________________________ elephant-devel site list elephant-devel@common-lisp.net http://common-lisp.net/mailman/listinfo/elephant-devel
