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Posted to dev@felix.apache.org by "Yann Diorcet (JIRA)" <ji...@apache.org> on 2011/07/07 15:18:16 UTC
[jira] [Created] (FELIX-3030) Bind/Unbind and lifecycle
Bind/Unbind and lifecycle
-------------------------
Key: FELIX-3030
URL: https://issues.apache.org/jira/browse/FELIX-3030
Project: Felix
Issue Type: Bug
Components: iPOJO
Affects Versions: iPOJO-1.8.0
Reporter: Yann Diorcet
According to my post(http://old.nabble.com/iPojo-lifecycle-and-dependencies-p32003301.html).
It seems that there is a problem with the lifecycle and dependencies.
@Component
@Instantiate
public final class Abcd {
@Requires
private Efg efg;
@Validate
private void start() {
}
@Invalidate
private void stop() {
}
@Bind(aggregate = true, optional = true)
private void bindXyz(final Xyz service) {
}
@Unbind
private void unbindXyz(final Xyz service) {
}
}
Scenario 1:
-A new service(Efg1) provides Efg
-A new service(Xyz1) provides Xyz
-The component Abcd is instantiated
-The bind() is called with Xyz1
-The start() of the component is called
-The Efg1 is unregistered
-The component is invalidated (Efg1 is gone) stop() is called
-During the time that my component is invalidated, if a new Xyz service(Xyz2) is registred (from an another bundle for example) bindXyz() is called
-After that, if i stop my bundle, my component will be stopped but unbindXyz() will be not called(neither for Xyz1 nor Xyz2).
Scenario 2:
-A new service(Efg1) provides Efg
-A new service(Xyz1) provides Xyz
-The component Abcd is instantiated
-The bind() is called with Xyz1
-The start() of the component is called
-The Efg1 is unregistered
-The component is invalidated (Efg1 is gone) stop() is called
-A new service(Efg2) provides Efg
-The start() of the component is called
Why all the already existing services are bound at the creation of the component and not unbound at the "destruction" of the component?
Another solution: Why don't bind the optional services at the validation of the component and unbind them at the invalidation (like it seems to be done with not optional service)?
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[jira] [Commented] (FELIX-3030) Bind/Unbind and lifecycle
Posted by "Clement Escoffier (Commented) (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/FELIX-3030?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13154057#comment-13154057 ]
Clement Escoffier commented on FELIX-3030:
------------------------------------------
The issue here is the mix between the instance lifecycle (VALID / INVALID) and the service dynamism (BIND/UNBIND). I understand your issue, but the promoted model is to clean everything during the @Invalidate callback, and not expecting an @Unbind callback. Indeed, if we call the unbind callback, how does the code knows if it's just an unbind of a used service or if it's an invalidation.
> Bind/Unbind and lifecycle
> -------------------------
>
> Key: FELIX-3030
> URL: https://issues.apache.org/jira/browse/FELIX-3030
> Project: Felix
> Issue Type: Bug
> Components: iPOJO
> Affects Versions: iPOJO-1.8.0
> Reporter: Yann Diorcet
>
> According to my post(http://old.nabble.com/iPojo-lifecycle-and-dependencies-p32003301.html).
> It seems that there is a problem with the lifecycle and dependencies.
> @Component
> @Instantiate
> public final class Abcd {
> @Requires
> private Efg efg;
> @Validate
> private void start() {
> }
> @Invalidate
> private void stop() {
> }
> @Bind(aggregate = true, optional = true)
> private void bindXyz(final Xyz service) {
> }
> @Unbind
> private void unbindXyz(final Xyz service) {
> }
> }
> Scenario 1:
> -A new service(Efg1) provides Efg
> -A new service(Xyz1) provides Xyz
> -The component Abcd is instantiated
> -The bind() is called with Xyz1
> -The start() of the component is called
> -The Efg1 is unregistered
> -The component is invalidated (Efg1 is gone) stop() is called
> -During the time that my component is invalidated, if a new Xyz service(Xyz2) is registred (from an another bundle for example) bindXyz() is called
> -After that, if i stop my bundle, my component will be stopped but unbindXyz() will be not called(neither for Xyz1 nor Xyz2).
> Scenario 2:
> -A new service(Efg1) provides Efg
> -A new service(Xyz1) provides Xyz
> -The component Abcd is instantiated
> -The bind() is called with Xyz1
> -The start() of the component is called
> -The Efg1 is unregistered
> -The component is invalidated (Efg1 is gone) stop() is called
> -A new service(Efg2) provides Efg
> -The start() of the component is called
> Why all the already existing services are bound at the creation of the component and not unbound at the "destruction" of the component?
> Another solution: Why don't bind the optional services at the validation of the component and unbind them at the invalidation (like it seems to be done with not optional service)?
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[jira] [Resolved] (FELIX-3030) Bind/Unbind and lifecycle
Posted by "Clement Escoffier (Resolved) (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/FELIX-3030?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Clement Escoffier resolved FELIX-3030.
--------------------------------------
Resolution: Won't Fix
Assignee: Clement Escoffier
> Bind/Unbind and lifecycle
> -------------------------
>
> Key: FELIX-3030
> URL: https://issues.apache.org/jira/browse/FELIX-3030
> Project: Felix
> Issue Type: Bug
> Components: iPOJO
> Affects Versions: iPOJO-1.8.0
> Reporter: Yann Diorcet
> Assignee: Clement Escoffier
>
> According to my post(http://old.nabble.com/iPojo-lifecycle-and-dependencies-p32003301.html).
> It seems that there is a problem with the lifecycle and dependencies.
> @Component
> @Instantiate
> public final class Abcd {
> @Requires
> private Efg efg;
> @Validate
> private void start() {
> }
> @Invalidate
> private void stop() {
> }
> @Bind(aggregate = true, optional = true)
> private void bindXyz(final Xyz service) {
> }
> @Unbind
> private void unbindXyz(final Xyz service) {
> }
> }
> Scenario 1:
> -A new service(Efg1) provides Efg
> -A new service(Xyz1) provides Xyz
> -The component Abcd is instantiated
> -The bind() is called with Xyz1
> -The start() of the component is called
> -The Efg1 is unregistered
> -The component is invalidated (Efg1 is gone) stop() is called
> -During the time that my component is invalidated, if a new Xyz service(Xyz2) is registred (from an another bundle for example) bindXyz() is called
> -After that, if i stop my bundle, my component will be stopped but unbindXyz() will be not called(neither for Xyz1 nor Xyz2).
> Scenario 2:
> -A new service(Efg1) provides Efg
> -A new service(Xyz1) provides Xyz
> -The component Abcd is instantiated
> -The bind() is called with Xyz1
> -The start() of the component is called
> -The Efg1 is unregistered
> -The component is invalidated (Efg1 is gone) stop() is called
> -A new service(Efg2) provides Efg
> -The start() of the component is called
> Why all the already existing services are bound at the creation of the component and not unbound at the "destruction" of the component?
> Another solution: Why don't bind the optional services at the validation of the component and unbind them at the invalidation (like it seems to be done with not optional service)?
--
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[jira] [Commented] (FELIX-3030) Bind/Unbind and lifecycle
Posted by "Yann Diorcet (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/FELIX-3030?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13061952#comment-13061952 ]
Yann Diorcet commented on FELIX-3030:
-------------------------------------
Hi,
We had a talk with Guillaume Sauthier about my problem and we have reached the conclusion that it is not a bug but more a lack of functionnality.
Take the following example:
I have a component (Abcd) that use many services (ServiceA) in order to register itself into them. This is an aggregate and optional dependency.
This component also requires another service(ServiceB) which is a mandatory dependency.
We want the following behaviour:
As long as my component is valid (a service of ServiceB type exists), my component is registered to all services of ServiceA type. Respectively, when the instance becomes invalid, I want to unregister my component from the service.
This behaviour is not so exotic, however it can't be reached without complexify the component code.
Indeed here is a solution: we added a flag that indicates if the instance is valid or not, then we keep this flag updated using the @Validate and @Invalidate methods. We must also manage registration / unregistration of the remaining services in @Validate / @Invalidate methods.
@Component
@Instantiate
public final class Abcd {
@Requires
private ServiceB efg;
private List<ServiceA> services = new LinkedList<ServiceA>();
private boolean started = false;
@Validate
private void start() {
for(ServiceA service: services)
{
service.register(this);
}
started = true;
}
@Invalidate
private void stop() {
started = false;
for(ServiceA service: services)
{
service.unregister(this);
}
}
@Bind(aggregate = true, optional = true)
private void bindServiceA(final ServiceA service) {
services.add(service);
if(started)
{
service.register(this);
}
}
@Unbind
private void unbindServiceA(final ServiceA service) {
services.remove(service);
if(started)
{
service.unregister(this);
}
}
}
It's not really user-friendly. Moreover, we had to duplicate the code handling registration/unregistration :'(
Finally, what we want is to have optional @Bind/Unbind methods to be only called when the instance is valid. That could be achieved by extending the dependency handler to support this feature.
>From a programming model POV, it could looks like the following (using annotation):
@Component
@Instantiate
public final class Abcd {
@Requires
private ServiceB efg;
@Validate
private void start() {
}
@Invalidate
private void stop() {
}
@Bind(aggregate = true, optional = true, componentValidated = true)
private void bindServiceA(final ServiceA service) {
service.register(this);
}
@Unbind
private void unbindServiceA(final ServiceA service) {
service.unregister(this);
}
}
Somehow each bind depends on the component state:
-The bind is done if the service is present AND if the component is valid
-The unbind is done if the service is no longer present OR if the component becomes invalid
WDYT ?
Thanks
> Bind/Unbind and lifecycle
> -------------------------
>
> Key: FELIX-3030
> URL: https://issues.apache.org/jira/browse/FELIX-3030
> Project: Felix
> Issue Type: Bug
> Components: iPOJO
> Affects Versions: iPOJO-1.8.0
> Reporter: Yann Diorcet
>
> According to my post(http://old.nabble.com/iPojo-lifecycle-and-dependencies-p32003301.html).
> It seems that there is a problem with the lifecycle and dependencies.
> @Component
> @Instantiate
> public final class Abcd {
> @Requires
> private Efg efg;
> @Validate
> private void start() {
> }
> @Invalidate
> private void stop() {
> }
> @Bind(aggregate = true, optional = true)
> private void bindXyz(final Xyz service) {
> }
> @Unbind
> private void unbindXyz(final Xyz service) {
> }
> }
> Scenario 1:
> -A new service(Efg1) provides Efg
> -A new service(Xyz1) provides Xyz
> -The component Abcd is instantiated
> -The bind() is called with Xyz1
> -The start() of the component is called
> -The Efg1 is unregistered
> -The component is invalidated (Efg1 is gone) stop() is called
> -During the time that my component is invalidated, if a new Xyz service(Xyz2) is registred (from an another bundle for example) bindXyz() is called
> -After that, if i stop my bundle, my component will be stopped but unbindXyz() will be not called(neither for Xyz1 nor Xyz2).
> Scenario 2:
> -A new service(Efg1) provides Efg
> -A new service(Xyz1) provides Xyz
> -The component Abcd is instantiated
> -The bind() is called with Xyz1
> -The start() of the component is called
> -The Efg1 is unregistered
> -The component is invalidated (Efg1 is gone) stop() is called
> -A new service(Efg2) provides Efg
> -The start() of the component is called
> Why all the already existing services are bound at the creation of the component and not unbound at the "destruction" of the component?
> Another solution: Why don't bind the optional services at the validation of the component and unbind them at the invalidation (like it seems to be done with not optional service)?
--
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