[vw7.7] Opentalk.OtWeakKeyDictionary bug?

> Date: March 2, 2010 1:28:15 PM
> From: "Mike Hales"<[hidden email]>
> To: [hidden email]
> Cc: "vwnc NC"<[hidden email]>
> Subject: Re: [vw7.7] Opentalk.OtWeakKeyDictionary bug?
>
> I've been wrestling with some of the same problems, and am glad to see this
> patch. One more thing I noticed when I was debugging some of these issues is
> in:
>
> RequestTransport>>newRequestId
>     "We hope that a request would not last long
>     enough to permit the reuse of an id number."
>
>     ^nextRequestId := (nextRequestId + 1) \\ 536870911
>
> If nextRequestId does reach 536870910 (ie. one shy of SmallInteger maxValue)
> when called again the nextRequestId will be zero, which is invalid as a key
> in an OtWeakKeyDictionary where this value is used, so this method should
> probably be:
>
> newRequestId
>     "We hope that a request would not last long
>     enough to permit the reuse of an id number."
>
>     ^nextRequestId := (nextRequestId + 1) \\ 536870911 max: 1
>
> That's quite a few requests, so the rollover may have never been tested.
>
> Mike
>
>
> Mike Hales
> Engineering Manager
> KnowledgeScape
> www.kscape.com
>
>
> On Tue, Mar 2, 2010 at 7:31 AM, <[hidden email]> wrote:
>
> > OK, here goes a bit more info about the associated ARs and fixes. the patch
> > is attached (also compressed in case some spam filters have .st alergies).
> > These were one of the very first fixes in OpentalkBase so should be directly
> > applicable to 7.7
> >
> > 58426: "More concerns about WeakKeyDictionary"
> > 58838: "OtWeak?Dictionary sporadically "loses" its entries for brief
> > periods of times (usually under load)"
> >
> > * made sure that reclaimElements is always followed by either grow, shrink
> > or rehash on every execution path at every call-site (finalizeElements,
> > grow)
> > * fixed includesKey: which was completely broken
> > * moved accessLock setup from makeDependent to initSize:, otherwise we
> > break the lock every time we grow or shrink
> > * added keysDo: because it is used by DictionaryInspector and so without it
> > you cannot inspect these dictionaries
> > * extended OtETimeout to capture the request and transport as well
> > * fixed OtWeakKeyDictionary>>reclaimElements to reclaim both keys and
> > values
> > * fixed OtW!
> > eakKeyDictionary>>atIndex:putKey:andValue: to look at key not value when
> > updating tally
> > * OtWeakKeyDictionary>>at:ifAbsentPut: to only grow if actually adding an
> > element
> > * minor optimization in OtWeakKeyDictionary>>at:put:
> >
> > [hidden email] wrote:
> > > We've had several reports of the weak dictionary not keeping tally in
> > sync with the contents. This should be fixed in 7.8 builds (OpentalkBase(7.8
> > - 2)). I'll extract the changes as a patch and post it here shortly.
> > >
> > > "Mark Plas"<[hidden email]> wrote:
> > > > Since using VW7.7, we sometimes encounter an endless loop in
> > OtWeakKeyDictionary.
> >
> > ....