Re: [osgi-dev] whiteboard pattern & extenders

[BJ Hargrave]

A is the extender now? I thought A was the whiteboard impl?

 

I think the use case it getting too far from an understandable example that I can't really reason about it anymore.

 

Can you please express the use case in some more concrete terms? I see you opened an Eclipse bug on this topic too, so there must be a really use case we can discuss and examine the package wirings and service relationships.

 

Basically, the whiteboard impl and the bundle whose context registered the whiteboard service must be wired to the same service package. Otherwise, you are not really in the whiteboard pattern anymore which is based upon shared whiteboard types.

 

--

BJ Hargrave
Senior Technical Staff Member, IBM // office: +1 386 848 1781
OSGi Fellow and CTO of the OSGi Alliance // mobile: +1 386 848 3788
hargr...@us.ibm.com

 

 

----- Original message -----
From: Raymond Auge <raymond.a...@liferay.com>
Sent by: osgi-dev-boun...@mail.osgi.org
To: OSGi Developer Mail List <osgi-dev@mail.osgi.org>
Cc:
Subject: Re: [osgi-dev] whiteboard pattern & extenders
Date: Wed, Jun 17, 2015 3:34 PM
 

extend this to any scenario where C) has some possibly logic but that is being extended by a bundle B) which isn't the tracker, that job belongs to an A) who is an extender.
 

I don't know... maybe B) should not be using A)'s bundleContext in order to register services?
 

- Ray

 

On Wed, Jun 17, 2015 at 3:31 PM, Raymond Auge <raymond.a...@liferay.com> wrote:

Actually Chris is correct in describing the scenario and BJ you are not correct.
 

C) is some bundle which has a header "ImCool: oh so cool!"

B) is an extender which makes servlets from the header "ImCool" IT knows how to make a Servlet service.

A) is the whiteboard

 

This doesn't work because C) does not import Servlet.
 

- Ray

 

On Wed, Jun 17, 2015 at 3:24 PM, BJ Hargrave <hargr...@us.ibm.com> wrote:

OK.

 

So A, the whiteboard impl, has ServiceTrackers and must care about the specific package.

 

B is the extends which registers the services. It has no ServiceTrackers and does not care about the package since it does not use the package itself.

 

C also must care about the same package as A (so they are type compatible).

 

So there is not bundle which both is the extender and registers the services and also has ServiceTrackers which must care about the specific package. Therefore trackAllServices=true is not needed.

 

--

BJ Hargrave
Senior Technical Staff Member, IBM // office: +1 386 848 1781
OSGi Fellow and CTO of the OSGi Alliance // mobile: +1 386 848 3788
hargr...@us.ibm.com

 

 

----- Original message -----
From: Raymond Auge <raymond.a...@liferay.com>
Sent by: osgi-dev-boun...@mail.osgi.org
To: OSGi Developer Mail List <osgi-dev@mail.osgi.org>
Cc:
Subject: Re: [osgi-dev] whiteboard pattern & extenders

Date: Wed, Jun 17, 2015 2:55 PM
 

 

 

On Wed, Jun 17, 2015 at 2:44 PM, BJ Hargrave <hargr...@us.ibm.com> wrote:

So this is like DS (an extender) registering Servlet services on behalf of a bundle using DS. Then of course the extender bundle does not care about the servlet package but also the extender bundle is not using ServiceTrackers to track the Servlet services. That is done by the Http Whiteboard impl bundle which does care about the servlet package and its version.

 

I'm sorry but you've lost me, and DS isn't an example of the scenario because the DS bundle is itself tracker in this scenario.
 

In the scenario I'm describing there are 3 bundles in play:
 

A) the whiteboard bundle (has the trackers)

B) an extender which registers services that the whiteboard

C) a bundle which is being extended by B) but doesn't know anything about A) or the API it's being extended with
 

Sincerely,

- Ray
 

 

--

BJ Hargrave
Senior Technical Staff Member, IBM office: +1 386 848 1781
OSGi Fellow and CTO of the OSGi Alliance mobile: +1 386 848 3788
hargr...@us.ibm.com

 

 

----- Original message -----
From: Raymond Auge <raymond.a...@liferay.com>
Sent by: osgi-dev-boun...@mail.osgi.org
To: OSGi Developer Mail List <osgi-dev@mail.osgi.org>
Cc:

Subject: Re: [osgi-dev] whiteboard pattern & extenders
Date: Wed, Jun 17, 2015 2:23 PM
 

But an extender who registers services to a whiteboard impl on behalf of extendee will result in those services not being visible to the whiteboard if the extendee does not import the packages used by the services?

 

On Wed, Jun 17, 2015 at 2:16 PM, BJ Hargrave <hargr...@us.ibm.com> wrote:

Well whiteboard and extenders are different.

 

Whiteboard should not use true since it cares about the specific API package version.

 

Extenders should use BundleTrackers rather than ServiceTrackers since they are not using whiteboard services.

 

--

BJ Hargrave
Senior Technical Staff Member, IBM office: +1 386 848 1781
OSGi Fellow and CTO of the OSGi Alliance mobile: +1 386 848 3788
hargr...@us.ibm.com

 

 

----- Original message -----
From: Raymond Auge <raymond.a...@liferay.com>
Sent by: osgi-dev-boun...@mail.osgi.org
To: OSGi Developer Mail List <osgi-dev@mail.osgi.org>
Cc:
Subject: [osgi-dev] whiteboard pattern & extenders
Date: Wed, Jun 17, 2015 2:12 PM
 

When implementing a whiteboard pattern should we always open trackers using the trackAllServices = true ? via:

ServiceTracker.open(true);
 

It would seem that this is the only way that we can support extenders where the extendee has no knowledge of the APIs in question, correct?

--

Raymond Augé (@rotty3000)

Senior Software Architect Liferay, Inc. (@Liferay)

Board Member & EEG Co-Chair, OSGi Alliance (@OSGiAlliance)

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Raymond Augé (@rotty3000)

Senior Software Architect Liferay, Inc. (@Liferay)

Board Member & EEG Co-Chair, OSGi Alliance (@OSGiAlliance)

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Raymond Augé (@rotty3000)

Senior Software Architect Liferay, Inc. (@Liferay)

Board Member & EEG Co-Chair, OSGi Alliance (@OSGiAlliance)

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Raymond Augé (@rotty3000)

Senior Software Architect Liferay, Inc. (@Liferay)

Board Member & EEG Co-Chair, OSGi Alliance (@OSGiAlliance)

--

Raymond Augé (@rotty3000)

Senior Software Architect Liferay, Inc. (@Liferay)

Board Member & EEG Co-Chair, OSGi Alliance (@OSGiAlliance)

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