Hello,

so after some tedious debugging (and fair amount of time figuring out how
lazy conversation work in this case) I managed to get to the state you
were seeing.

I think this is a bug - Weld doesn't fire @Initialized event in case where
user attempts to restore non-existing conversation.

We correctly associate the request with new conversation before the exception
is thrown (which is what spec requires and tests) but we don't fire the
event.

Issue is here - 
https://issues.redhat.com/browse/WELD-2611

And I've proposed a fix here - 
https://github.com/weld/core/pull/1962

If you could try that and tell me if it works, that would be great.

Although I did use the same reproducer, so hopefully it'll work ;-)

Regards and have a nice weekend!

Matej

----- Original Message -----

> From: "Benjamin Confino" <BENJAMIC@uk.ibm.com>

> To: "Matej Novotny" <manovotn@redhat.com>

> Cc: "Takayuki T Ishii" <EBB0F3L@jp.ibm.com>, weld-dev@lists.jboss.org

> Sent: Friday, January 31, 2020 1:20:50 AM

> Subject: RE: [weld-dev] Question about conversations scope initilization

obeserver

> 

> Hello Matej

> 

> After testing adding a call to `bean.getMsg` in the catch block, the

> behaviour is unchanged. I did some further digging and here's what
I

> found:

> 

> On a fresh start of the sever I ping the url with a nonsense cid.

> 

> ConversationBean will call conversation.begin() in the try block.
This

> triggers a codepath that leads to

> LazyHttpConversationContextImpl.checkContextInitialized() line 124,
that

> line will throw an exception. We go back out to ConversationBean where
the

> exception is caught. Then when the catch block calls conversation.begin()

> it will once again reach

> LazyHttpConversationContextImpl.checkContextInitialized() but this
time

> the if statement on line 121 returns true and so we never call

> initialize(). In both cases it is the same

> LazyHttpConversationContextImpl.

> 

> I also put a breakpoint in the observer and pinged the URL without

> manually specificing a cid. From inside the observer method I can
see that

> LazyHttpConversationContextImpl.checkContextInitialized() line 128
is on

> the stack.

> 

> 

> So to summarise. When I call the url with a nonsense cdi: The try
block

> reaches checkContextInitialized and gets an exception on line 121.
Then

> the catch block reaches checkContextInitialized and does nothing because

> isInitialized() returns true. Thus neither attempt reaches line 128
and

> the observer method is never fied.

> 

> This feels like a bug to me, not just because the observer isn't fired
but

> also because if the initilization method had an exception half way
though

> is it left in a good state? I don't know enough about these weld internals

> to check.

> 

> It occurs to me that one possible fix is to swap line 89 with line
90 so

> that the exception takes place before initilized is set to true. Of
course

> that assumes that running initilized twice won't cause worse problems.

> 

> What do you think? Is this a bug?

> 

> 

> 

> From:   Matej Novotny <manovotn@redhat.com>

> To:     Benjamin Confino <BENJAMIC@uk.ibm.com>

> Cc:     Takayuki T Ishii <EBB0F3L@jp.ibm.com>, weld-dev@lists.jboss.org

> Date:   28/01/2020 15:03

> Subject:        [EXTERNAL] Re: [weld-dev] Question
about conversations

> scope initilization     obeserver

> 

> 

> 

> Hello,

> 

> I think I know what is the "problem" here.

> Weld uses lazy conversation init - that means we don't activate context

> until you try and access a conversation scoped bean.

> 

> Now, in your example, the ConversationBean tries to begin() a

> conversation, then calls the bean (which initializes the context and

> notifies the observer).

> However, in the situation where you try and pass in a non-existing

> conversation, the invocation to conversation.begin()[1] will blow
up with

> NonExistingConversationException and

> you will jump right into the catch block[2] where you begin a conversation

> with given ID, but you no longer invoke the bean, hence the context
won't

> get activated.

> Try adding the `bean.getMsg()` call to the catch block and see if
that

> helps.

> 

> Note that CDI spec sets no requirements on how/when to activate the

> conversation context, so the lazy behaviour is compliant with spec
(and

> this is also why you saw no such test in TCKs).

> 

> Regards

> Matej

> 

> _________________________________________________________________________________

> [1]

> 
https://gist.github.com/manovotn/b9e9fde25ab77b5e481d5b34edf02b0c#file-conversationbean-java-L4

> 

> [2]

> 
https://gist.github.com/manovotn/b9e9fde25ab77b5e481d5b34edf02b0c#file-conversationbean-java-L10-L16

> 

> 

> 

> 

> ----- Original Message -----

> > From: "Benjamin Confino" <BENJAMIC@uk.ibm.com>

> > To: "Matej Novotny" <manovotn@redhat.com>

> > Cc: "Takayuki T Ishii" <EBB0F3L@jp.ibm.com>,
weld-dev@lists.jboss.org

> > Sent: Tuesday, January 28, 2020 12:06:14 PM

> > Subject: RE: [weld-dev] Question about conversations scope initilization

>          obeserver

> > 

> > Hello

> > 

> > Thanks for the link. I had a look but I couldn't find any TCK
tests

> > checking to see if an observer method will catch the new

> > ConversationContext being created for the "new transient
conversation".

> To

> > check if a new conversation was activated I created an entirely
fresh

> > server and ran the test application on it, the behaviour was
the same,

> the

> > first url I pinged on this new server ended with "cid="
and the observer

> > didn't . Normally I've just been restarting the old server but

> restarting

> > frequently.

> > 

> > I've attached the recreate you requested. it consists of the
three

> classes

> > attached to my previous email as well as a minimal html page.
To run it

> > load it onto your server and ping

> > 

> 
http://localhost:9080/ConversationContextTest/index.xhtml

>  to see the

> > observer fire, and

> > 

> 
http://localhost:9080/ConversationContextTest/index.xhtml?cid=99999

>  to see

> > the observer fail to fire.

> > 

> > Best regards

> > Benjamin

> > 

> > 

> > 

> > From:   Matej Novotny <manovotn@redhat.com>

> > To:     Benjamin Confino <BENJAMIC@uk.ibm.com>

> > Cc:     weld-dev@lists.jboss.org, Takayuki T Ishii
<EBB0F3L@jp.ibm.com>

> > Date:   27/01/2020 11:39

> > Subject:        [EXTERNAL] Re: [weld-dev]
Question about conversations

> > scope initilization     obeserver

> > 

> > 

> > 

> > Hello,

> > 

> > I'd start by pointing you to CDI TCK as that's a good starting
point to

> > see what's covered.

> > For your question, that would be this test -

> > 

> 
https://github.com/eclipse-ee4j/cdi-tck/blob/master/impl/src/main/java/org/jboss/cdi/tck/tests/context/conversation/ClientConversationContextTest.java#L344-L349

> 

> > 

> > And possibly few more in the same test class.

> > 

> > As for the linked classes - your `ConversationBean` is listening
for

> > @Initialized event. Can you verify that a new conversation was
activated

> > for your request instead of verifying that context was activated?

> > E.g. check IDs or something along those lines? I suppose that
will hold

> > true and in that case it works just as spec requires it to.

> > From the top of my head I don't really know how we activate/deactivate

> > ConversationContext, I'd need to dig that up, but looking at
CDI spec,

> it

> > doesn't mandate that it is activated every time again and it
could

> already

> > be active for given request.

> > Plus from just the classes you linked, I cannot know if you test
this

> with

> > no existing conversation or maybe with some long running one
before you

> > try to send a request for non-existing one...and so on.

> > So if the above doesn't is not enough to answer your question,
then

> we're

> > going to need a complete reproducer so that we both talk about
the same

> > scenario :)

> > 

> > Matej

> > 

> > ----- Original Message -----

> > > From: "Benjamin Confino" <BENJAMIC@uk.ibm.com>

> > > To: weld-dev@lists.jboss.org

> > > Cc: "Takayuki T Ishii" <EBB0F3L@jp.ibm.com>

> > > Sent: Monday, January 27, 2020 11:42:14 AM

> > > Subject: [weld-dev] Question about conversations scope initilization

> > obeserver

> > > 

> > > Hello

> > > 

> > > I have a customer who's sent me a sample application, I
have attached

> > the

> > > source to it below.

> > > 

> > > When the customer visits index.xhtml they see the following
output:

> > > 

> > > Conversation initialized.

> > > Conversation begun. 
cid:1

, timeout:3600000

> > > Conversation destroyed. 
cid:1

> > > 

> > > However when they append "?cdi=" or a non-existnant
identifier like

> > > "?cdi=10000" to the url they do not see "Conversation
initialized."

> > > 

> > > The CDI spec says that: If the propagated conversation cannot
be

> > restored,

> > > the container must associate the request with a new transient

> > conversation

> > > and throw an exception of type

> > > javax.enterprise.context.NonexistentConversationException.

> > > 

> > > I'm wondering if this should apply here? Or would it only
apply if the

> > cid

> > > pointed to an existing conversation that could not be restored?
And is

> > there

> > > anything in the spec that covers this specific situation?

> > > 

> > > Unless stated otherwise above:

> > > IBM United Kingdom Limited - Registered in England and Wales
with

> number

> > > 741598.

> > > Registered office: PO Box 41, North Harbour, Portsmouth,
Hampshire PO6

> > 3AU

> > > 

> > > _______________________________________________

> > > weld-dev mailing list

> > > weld-dev@lists.jboss.org

> > > 

> > 

> 
https://lists.jboss.org/mailman/listinfo/weld-dev

> 

> > 

> > 

> > 

> > 

> > 

> > Unless stated otherwise above:

> > IBM United Kingdom Limited - Registered in England and Wales
with number

> > 741598.

> > Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire
PO6

> 3AU

> > 

> 

> 

> 

> 

> Unless stated otherwise above:

> IBM United Kingdom Limited - Registered in England and Wales with
number

> 741598.

> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire
PO6 3AU

> 