[Vm-dev] SequenceableCollection VM crash (was Re: [Pharo-users] XMLOrderedList Concantenation)

[Eliot Miranda]

Hi Ben,


On Mon, May 5, 2014 at 10:27 AM, Ben Coman <btc at openinworld.com> wrote:

>
>  Just reporting, while looking into a query on [pharo-users] (which is
> attached for initial context only and can probably be deleted from any
> replies) I managed to crash the VM by evaluating the following in Workspace:
>
> a := SequenceableCollection new.
> a add: 1.
> a , SequenceableCollection new.
>

What's the image, the OS and the VM version?


>
> Now the interesting thing is that while the system becomes immediately
> sluggish, Pharo.exe crashes about 20 seconds later.
>
> This is with Pharo 3.0 Release (30846)
> http://files.pharo.org/platform/Pharo3.0-win.zip (dated 2014-04-30)
> on Windows Home Premium 64-bit SP1.
>
> cheers -ben
>
> Ben Coman wrote:
>
>
> Thanks. That info made it much easier to try.  Sorry I didn't end up with
> an answer for you, but I confirm there is some issue here, or something new
> I can learn when other chip in.
>
> Here is what I tried.
>
> * Installed XMLParser (monty.58) from Configuration Browser in Pharo 3.
>
> * Ran your code. Got the same error.
>
> * From the call stack I observed that
> XMLOrderedCollection(SequenceableCollection)>>copyReplaceFrom:to:with:
> has the line "newSequenceableCollection := self species new: newSize."
> such that it seems your error might be reduced to the question of why the
> following two snippets fail:
>     d := OrderedCollection new: 1.
>     d at: 1 put: 1.
>
>     e := OrderedCollection new: 3.
>     e at: 2 put: 1.
>
> However I'm sorry that is beyond my knowledge, and I'm hoping someone else
> can chip in so I can learn something.
>
> Pushing on, I noticed that XMLOrderedList has an instance variable
> /collection/ which holds the OrderedCollection.
>
> Now I wonder (without great experience and hoping to learn something) if
> it smells funny that XMLOrderedList inherits all of SequencableCollection
> methods that can not operate on /collection/.
>
> I noticed that XMLOrderedList was using an inherited
> SequenceableCollection>>copyReplaceFrom:to:with
> while OrderedCollection overrode that method with its own. So taking
> inspiration XMLOrderedList>>copyFrom:to: to override
> SequencableCollection>>copyReplaceFrom:to:with: to work with /collection/
> seems to solve your problem:
>     XMLOrderedList>>copyReplaceFrom: start to: stop with:
> replacementCollection
>         ^ self newWithCollection:
>             (collection copyReplaceFrom: start to: stop with:
> replacementCollection )
>
>
> Along the way I noticed a few (possible) bugs that seems not related to
> your problem:
>
> * When stepping through XMLOrderedList>>setCollection:
> there is a red-box-of-death for the instance variables, which can be
> solved by defining the following.
>     XMLOrderedList>>size
>         ^ collection ifNil: [ 0 ] ifNotNil: [ collection size]
>
> * In the debugger the /collection/ instance variable is not shown! (e.g.
> line XMLOrderedList>>at:put:).
> Can someone confirm this should show?
>
> HTH
> cheers -ben
>
> Thushar G R wrote:
>
> XMLOrderedList belongs to package XML-Parser-Nodes.
>
>  a := XMLOrderedList new.
> a add:'1'.
> a , XMLOrderedList new.
>
>  Here select all and Do it. On line 3 (a , XMLOrderedList new.)  i am
> expected to get a copy of 'a' , but instead it throws an error
> SubscriptOutOfBounds.
>
>
>
>
>  OrderedCollection(Object)>>errorSubscriptBounds:
> OrderedCollection>>ensureBoundsFrom:to:
> OrderedCollection>>at:put:
> OrderedCollection(SequenceableCollection)>>replaceFrom:to:with:startingAt:
> XMLOrderedList>>replaceFrom:to:with:startingAt:
> XMLOrderedList(SequenceableCollection)>>copyReplaceFrom:to:with:
> XMLOrderedList(SequenceableCollection)>>,
> UndefinedObject>>DoIt
> OpalCompiler>>evaluate
> SmalltalkEditor>>evaluateSelectionAndDo:
> PluggableTextMorph>>inspectIt in Block: [ textMorph editor
> evaluateSelectionAndDo: [ :resu...etc...
> PluggableTextMorph>>handleEdit: in Block: [ result := editBlock value ]
> TextMorphForEditView(TextMorph)>>handleEdit:
> PluggableTextMorph>>handleEdit:
> PluggableTextMorph>>inspectIt
> SmalltalkEditor class>>buildSmalltalkEditorKeymappingsOn: in Block: [
> :morph | morph inspectIt ]
> BlockClosure>>cull:
> BlockClosure>>cull:cull:
> BlockClosure>>cull:cull:cull:
> KMCategoryBinding>>completeMatch:buffer:
> KMKeymap>>notifyCompleteMatchTo:buffer: in Block: [ :l | l completeMatch:
> self buffer: aBuffer ]
> Array(SequenceableCollection)>>do:
> KMKeymap>>notifyCompleteMatchTo:buffer:
> KMKeymap>>onMatchWith:notify:andDo:
> KMCategory>>onMatchWith:notify:andDo: in Block: [ :entry | entry
> onMatchWith: anEventBuffer notify...etc...
> Set>>do:
> KMCategory>>onMatchWith:notify:andDo:
> KMCategoryBinding>>verifyMatchWith:notifying:thenDoing:
> KMDispatcher>>dispatch: in Block: [ :aTarget | ...
> OrderedCollection>>do:
>
>
>  Plese refer to the above stack.
>
>  Thanks in advance.
>
>  thushar
>
>
> On Mon, May 5, 2014 at 6:28 PM, Ben Coman <btc at openinworld.com> wrote:
>
>>  Thushar G R wrote:
>>
>>> Hi,
>>>
>>> I am getting an error while doing this.
>>>
>>> a := XMLOrderedList new.
>>> a add:'1'.
>>> a , XMLOrderedList new.
>>>
>>> Thanks,
>>>
>>> Thushar
>>>
>>  I could give you "an answer" ;) - but it would be what you wanted.  It
>> would help if you told what the error was, where it occurs (which of the
>> three lines), and what you expect each line is doing (especially the third
>> line).
>>
>> Also I don't see XMLOrderedList in the default Pharo image, so it would
>> help if you describe where you got that from and how you installed it.
>>
>> cheers -ben
>>
>>
>
>
>
>


-- 
best,
Eliot
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