[elephant-devel] Error: The slot ELEPHANT::INSTANCE-TABLE is unbound

[Red Daly]

Here is the patch.  I identified a boostrapping issue:

(setf (instances-cache instance) (indices instance)) was being called
on an instance of BDB-INDEXED-BDB, forcing a deserialization of the
persistent INDICES slot.  Unfortunately at this point in bootstrapping
the database, instance-table is not yet set up, so deserialization
does not quite work to fetch the persistent value of the INDICES slot.

I correct this bug by defining a custom reader that lazily loads the
indices-cache slot.  Not the smoothest bug fix, but it seems to work.

- Red


On Sat, Jul 10, 2010 at 1:00 PM, Red Daly <reddaly at gmail.com> wrote:
> When I try to open a controller of mine, I get this error:
>
> The slot ELEPHANT::INSTANCE-TABLE is unbound in the object
> #<BDB-STORE-CONTROLLER ...>
>
> It seems that this is caused by a bug with how the instance-table is
> established in a new controller, since the stack trace indicates this
> bug occurs when the INSTANCE-TABLE slot is being set up.
> Specifically, at this line in bdb-controller.lisp:
>
>
>      (setf (slot-value sc 'instance-table)
>              (if (or new-p (elephant::prior-version-p
> (database-version sc) '(0 9 1)))
>                  ;; When opening the DB equal or prior to 0.9.1,
> always get the indices initialized,
>                  ;; regardless of the indices is initialized before.
>                  ;; Even the indices is serialized before(in the case
> that open the <=0.9.1 DB file for the second time),
>                  ;; it still can not be unserialized here, because
> its persistent object's oid
>                  ;; does not match the hardcoded one in
> oid->schema-id, which only work on the DB file
>                  ;; created in release > 0.9.1.
>                  (make-instance 'bdb-indexed-btree :from-oid -3 :sc
> sc :indices (make-hash-table))
>>>>>                  (make-instance 'bdb-indexed-btree :from-oid -3 :sc sc))) <<<<
>
>
> I will work on a fix now.  If anybody has insights, gotchas, etc. let
> me know.  A patch soon to follow...
>
> The slot ELEPHANT::INSTANCE-TABLE is unbound in the object
> #<BDB-STORE-CONTROLLER /apps/bookllama-dev/server/data/production/>.
>   [Condition of type UNBOUND-SLOT]
>
> Restarts:
>  0: [USE-VALUE] Return a value as the slot-value.
>  1: [STORE-VALUE] Store and return a value as the slot-value.
>  2: [RETRY] Retry SLIME REPL evaluation request.
>  3: [ABORT] Return to SLIME's top level.
>  4: [TERMINATE-THREAD] Terminate this thread (#<THREAD
> "new-repl-thread" RUNNING {10054B88F1}>)
>
> Backtrace:
>  0: ((SB-PCL::FAST-METHOD SLOT-UNBOUND (T T T)) ..)
>  1: (SB-PCL::SLOT-UNBOUND-INTERNAL #<BDB-STORE-CONTROLLER
> /apps/bookllama-dev/server/data/production/> 9)
>  2: ((SB-PCL::FAST-METHOD ELEPHANT::OID->SCHEMA-ID (T
> ELEPHANT:STORE-CONTROLLER)) #<unavailable lambda list>)
>  3: ((SB-PCL::FAST-METHOD ELEPHANT::GET-INSTANCE-CLASS
> (ELEPHANT:STORE-CONTROLLER T)) #<unavailable lambda list>)
>  4: ((FLET SB-THREAD::WITH-RECURSIVE-LOCK-THUNK))
>  5: ((FLET #:WITHOUT-INTERRUPTS-BODY-[CALL-WITH-RECURSIVE-LOCK]324))
>  6: (SB-THREAD::CALL-WITH-RECURSIVE-LOCK ..)
>  7: ((FLET #:FORM-FUN-[CONTROLLER-RECREATE-INSTANCE]14))
>  8: ((SB-PCL::FAST-METHOD ELEPHANT::CONTROLLER-RECREATE-INSTANCE
> (ELEPHANT:STORE-CONTROLLER T)) ..)
>  9: ((LABELS ELEPHANT-SERIALIZER2::%DESERIALIZE)
> #S(ELEPHANT-MEMUTIL:BUFFER-STREAM :BUFFER
> #<SB-ALIEN-INTERNALS:ALIEN-VALUE :SAP #X00650120 :TYPE (* #)> :SIZE 76
> :POSITION 76 :LENGTH 80))
>  10: ((LABELS ELEPHANT-SERIALIZER2::%DESERIALIZE)
> #S(ELEPHANT-MEMUTIL:BUFFER-STREAM :BUFFER
> #<SB-ALIEN-INTERNALS:ALIEN-VALUE :SAP #X00650120 :TYPE (* #)> :SIZE 76
> :POSITION 76 :LENGTH 80))
>  11: (ELEPHANT-SERIALIZER2::DESERIALIZE ..)
>  12: ((FLET #:FORM-FUN-[DESERIALIZE]2))
>  13: (ELEPHANT::DESERIALIZE ..)
>  14: ((LAMBDA ()) #<unavailable lambda list>)
>  15: (SLOT-VALUE #<BDB-INDEXED-BTREE oid:-3> DB-BDB::INDICES)
>  16: ((SB-PCL::FAST-METHOD SHARED-INITIALIZE :AFTER
> (DB-BDB::BDB-INDEXED-BTREE T)) #<unavailable lambda list>)[:EXTERNAL]
>  17: ((LAMBDA (SB-PCL::.PV. SB-PCL::.NEXT-METHOD-CALL. SB-PCL::.ARG0.
> SB-PCL::.ARG1. SB-INT:&MORE SB-PCL::.DFUN-MORE-CONTEXT.
> SB-PCL::.DFUN-MORE-COUNT.)) ..)
>  18: ((SB-PCL::FAST-METHOD SHARED-INITIALIZE :AROUND
> (ELEPHANT:PERSISTENT-OBJECT T)) #<unavailable argument> #<unavailable
> argument> #<unavailable argument> #<unavailable argument>)[:EXTERNAL]
>  19: ((LAMBDA (SB-PCL::.PV. SB-PCL::.NEXT-METHOD-CALL. SB-PCL::.ARG0.
> SB-INT:&MORE SB-PCL::.DFUN-MORE-CONTEXT. SB-PCL::.DFUN-MORE-COUNT.))
> ..)
>  20: (SB-PCL::FAST-MAKE-INSTANCE #<unavailable argument>)[:EXTERNAL]
>  21: ((LAMBDA ()))
>  22: ((SB-PCL::FAST-METHOD ELEPHANT::EXECUTE-TRANSACTION
> (DB-BDB::BDB-STORE-CONTROLLER T)) #<unavailable argument>
> #<unavailable argument> #<unavailable argument> #<unavailable
> argument>)[:EXTERNAL]
>  23: ((SB-PCL::FAST-METHOD ELEPHANT::OPEN-CONTROLLER
> (DB-BDB::BDB-STORE-CONTROLLER)) #(13 NIL 9 NIL 3 NIL ...) #<unused
> argument> #<BDB-STORE-CONTROLLER
> /apps/bookllama-dev/server/data/production/>)[:EXTER..
>  24: ((LAMBDA (SB-PCL::.PV. SB-PCL::.NEXT-METHOD-CALL. SB-PCL::.ARG0.
> SB-INT:&MORE SB-PCL::.DFUN-MORE-CONTEXT. SB-PCL::.DFUN-MORE-COUNT.))
> ..)
>  25: (ELEPHANT:OPEN-STORE #<unavailable lambda list>)[:EXTERNAL]
>
>
> -- Red