Re: [equinox-dev] NPE from RegistryStrategyOSGI.onStop()

[Thomas Watson <tjwatson@xxxxxxxxxx>]

The package org.eclipse.core.runtime
package is split.  The following Require-Bundle header should have
given you all the access you needed to the extension registry classes:

Require-Bundle: org.eclipse.equinox.registry


From the stack trace it looks more like
the org.eclipse.equinox.registry bundle was shutdown before your bundle
had a chance to shutdown.  Currently Equinox will shutdown all lazy-start
bundles before "normal" bundles are shutdown.  Since org.eclipse.equinox.registry
is lazy-started that means it is guaranteed to be shutdown before your
registry.test bundle.  Equinox will not let a class be loaded from
a lazy-start bundle if it is already shutdown.  One way to work around
this issue is to make your registry.test bundle a lazy-start bundle (by
adding the "Eclipse-LazyStart: true" header).  This will
ensure your bundle is shutdown before the org.eclipse.equinox.registry
bundle because it depends on the org.eclipse.equinox.registry bundle.

In the current 3.3 release we are looking
to improve the lazy-start specification.  One improvement is in the
area of shutdown order.  This would prevent the need to specify Eclipse-LazyStart
in your bundle simply because you depend on a lazy-start bundle.  For
reference bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=135885 is tracking
the lazy-start changes we are planning for the 3.3 release.

Tom

Simon J Archer/Raleigh/IBM@IBMUS
Sent by: equinox-dev-bounces@xxxxxxxxxxx

10/22/2006 10:11 PM

Please respond to
Equinox development mailing list <equinox-dev@xxxxxxxxxxx>

To	Equinox development mailing list <equinox-dev@xxxxxxxxxxx>
cc	"Equinox development mailing list" <equinox-dev@xxxxxxxxxxx>, equinox-dev-bounces@xxxxxxxxxxx
Subject	Re: [equinox-dev] NPE from RegistryStrategyOSGI.onStop()

Looking in your manifest.mf I see this: 

Manifest-Version: 1.0 
Bundle-ManifestVersion: 2 
Bundle-Name: Test Plug-in 
Bundle-SymbolicName: registry.test 
Bundle-Version: 1.0.0 
Bundle-Activator: registry.test.Activator 
Bundle-Localization: plugin 
Import-Package: org.osgi.framework;version="1.3.0"
Require-Bundle: org.eclipse.equinox.registry 

Whenever you get a NoClassDefFoundError that most likely cause is that
you incorrectly defined the bundle's dependencies in the manifest.mf.  Since
the IExtensionRegistry class is in the bundle org.eclipse.core.runtime
you MUST do one of the following: 

- Use the Import-Package header to declare a dependency on the *package*
org.eclipse.core.runtime. 
- Use the Require-Bundle header to declare your dependency on the *bundle*
org.eclipse.core.runtime. 

Either will work.  Sometimes it is hard for people to decide which
header to use.  My rule of thumb is as follows:

- If you absolutely depend upon the bundle then use Require-Bundle.  This
is most often the case when you are extending an extension-point defined
in a particular bundle.  Since there is never a possibility that another
bundle could provide the extension point on which you dependent it makes
sense to always use Require-Bundle for this sort of dependency.

- If all you care about is a code dependency on a particular type in a
particular package then use Import-Package.  This is the case where
you are depending on an implementer of some well defined API and you really
don't care who the provider is, so long as it provides the correct API.
 Use Import-Package when there could be multiple exporters of the
package on which  you depend, otherwise just use Require-Bundle.

I hope this helps, 

Simon

"Jason Hao" <jason.hao@xxxxxxxxx>
Sent by: equinox-dev-bounces@xxxxxxxxxxx

10/22/2006 10:54 PM

Please respond to
Equinox development mailing list <equinox-dev@xxxxxxxxxxx>

To	"Equinox development mailing list" <equinox-dev@xxxxxxxxxxx>
cc
Subject	Re: [equinox-dev] NPE from RegistryStrategyOSGI.onStop()

Oleg,

Thanks for you quick answer. I tried your suggestion but it didn't work
as you described. I added an activator class into MyBundle. MyBundle's
activator#start() is called after
org.eclipse.equinox.registry's. And so does the activator#stop().This is
even worse. Because I got another exception in MyBundle's activator#stop()
method.

java.lang.NoClassDefFoundError: org/eclipse/core/runtime/IExtensionRegistry
   at registry.test.Activator.stop(Activator.java:30)
   at org.eclipse.osgi.framework.internal.core.BundleContextImpl$3.run
(BundleContextImpl.java:1032)
   at java.security.AccessController.doPrivileged(Native Method)
   at org.eclipse.osgi.framework.internal.core.BundleContextImpl.stop(BundleContextImpl.java:1028)
   at org.eclipse.osgi.framework.internal.core.BundleHost.stopWorker
(BundleHost.java:396)
   at org.eclipse.osgi.framework.internal.core.AbstractBundle.suspend(AbstractBundle.java:502)
   at org.eclipse.osgi.framework.internal.core.Framework.suspendBundle(Framework.java:1067)
   at org.eclipse.osgi.framework.internal.core.StartLevelManager.decFWSL(StartLevelManager.java:619)
   at org.eclipse.osgi.framework.internal.core.StartLevelManager.doSetStartLevel(StartLevelManager.java:283)
   at org.eclipse.osgi.framework.internal.core.StartLevelManager.shutdown
(StartLevelManager.java:256)
   at org.eclipse.osgi.framework.internal.core.SystemBundle.suspend(SystemBundle.java:190)
   at org.eclipse.osgi.framework.internal.core.Framework.shutdown(Framework.java:537)
   at org.eclipse.osgi.framework.internal.core.OSGi.shutdown(OSGi.java:61)
   at org.eclipse.osgi.framework.internal.core.FrameworkCommandProvider._shutdown(FrameworkCommandProvider.java:214)
   at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
   at java.lang.reflect.Method.invoke (Method.java:597)
   at org.eclipse.osgi.framework.internal.core.FrameworkCommandInterpreter.execute(FrameworkCommandInterpreter.java:145)
   at org.eclipse.osgi.framework.internal.core.FrameworkConsole.docommand(
FrameworkConsole.java:293)
   at org.eclipse.osgi.framework.internal.core.FrameworkConsole.console(FrameworkConsole.java:278)
   at org.eclipse.osgi.framework.internal.core.FrameworkConsole.run(FrameworkConsole.java
:213)
   at java.lang.Thread.run(Thread.java:619)

I attached the test bundle for your reference.

On 10/21/06, Oleg Besedin <
obesedin@xxxxxxxxxx> wrote: 

Hi Jason, 
The quick answer is that you need to stop your custom registry before org.eclipse.equinox.registry
bundle is stopped. 

Normally bundles are stopped in the reverse order of dependency, i.e.,
if a bundle MyBundle depends on the org.eclipse.equinox.registry, then
MyBundle is stopped first on shutdown, then org.eclipse.equinox.registry.
So, normally, you could put the code to stop your custom registry into
MyBundle's activator#stop(). 

I *guess* that putting inappropriate bundle start levels could break the
shutdown order. 

Thanks, 
Oleg

"Jason Hao" <jason.hao@xxxxxxxxx >
Sent by: equinox-dev-bounces@xxxxxxxxxxx

10/20/2006 03:52 AM

Please respond to
Equinox development mailing list <equinox-dev@xxxxxxxxxxx>

To	equinox-dev@xxxxxxxxxxx
cc
Subject	[equinox-dev] NPE from RegistryStrategyOSGI.onStop()

Hi all,

I'm working on a project which is based on OSGi and equinox. The project
also includes equinox extension registry bundle. Since my extensions are
defined in files which are not in side the bundles, I need to load these
extensions into registry by IExtensionRegistry.addContribution() method.
And addContribution() method needs the master token which is under control
of equinox registry bundle and I can't get it, so I have to create my registry
instead of using the default registry. Here are what I have done. 

1.        Add "-Declipse.createRegistry=false"
into VM arguments. This will disable the default registry. 
2.        Create my extension registry
component and register it with declarative service spec. In the activate()
method I creat my OSGi strategy and registry. In the deactivate() method
I call IExtensionRegistry.stop() method to stop the registry. 
3.        Start my application
and the registry works well. 
4.        Shutdown the OSGi framework
by typing "shutdown" command in the console. org.eclipse.core.internal.registry.osgi.Activator.stop
() method is called and the bundle context is set to null. Then my registry
deactivate() method is called. I got java.lang.NullPointerException from
org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.onStop(RegistryStrategyOSGI.java
:204) since the bundle context is null. 
I wonder if there's any way I can work around. Thanks.

-- 
Best Regards,

Jason Hao _______________________________________________
equinox-dev mailing list
equinox-dev@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/equinox-dev


_______________________________________________
equinox-dev mailing list
equinox-dev@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/equinox-dev





-- 
Best Regards,

Jason Hao [attachment "registry.test.zip" deleted by Simon J
Archer/Raleigh/IBM] _______________________________________________
equinox-dev mailing list
equinox-dev@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/equinox-dev
_______________________________________________
equinox-dev mailing list
equinox-dev@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/equinox-dev