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Posted to dev@harmony.apache.org by Mark Hindess <ma...@googlemail.com> on 2009/05/19 09:24:40 UTC
Re: Question about the boot and classloading
In message <df...@mail.gmail.com>, tian
galaxy writes:
>
> OK ,thanks .Seems the minimal class set has been defined by the osgi.
Not sure how this helps though. The OSGi Minimum Execution Environment
says what is theoretically the minimum required to run OSGi. What we
need to concern ourselves with is the *practical* minimum and that
really depends on our implementation details.
I don't think that we should implement OSGi in the VM. Instead the
existing bootstrap classloader should load the OSGi framework (with
a unique classloader) and the system classes (with a "temporary"
classloader). Once the OSGi framework is configured the system classes
need to be moved to the correct classloader for the OSGi bundle to which
they belong.
This means that during the initial starting-OSGi-framework phase
the OSGi bundle import/exports will not be enforced but, other than
implementing OSGi in the VM, I don't see how to avoid this.
The multiplicity of bootstrap classloaders still needs to be hidden
since the API demands that getClassLoader should return null for the
bootstrap classloader(s).
The biggest problem is probably how to implement this as VM-independent
API such that a VM wanting to implement OSGi had to provide only a
minimal C/Java interface in order to gain OSGi support.
Regards,
Mark.
> I will look more closely on this problems and let you know if there some
> progresses made.
> Thanks a lot !
> 2009/5/18 Pavel Pervov <pm...@gmail.com>
>
> > I do not know osgi model in detail, but what minimal set of classes is
> > needed to start osgi model itself? Then we could delegate to "system"
> > bundle loader from bootstrap classloader.
> >
> > 2009/5/18, tian galaxy <ha...@gmail.com>:
> > > Yes , implement osgi loading model in there is too complex.
> > >
> > > We know some modules are more important than others , performing some
> > > fundamental , basic functions .
> > > Is it possible to only load these more" basic " modules with bootstrap
> > class
> > > loader and make the other modules work the osgi bundle?
> > > Actually I don't quite understand why system classes could only be loaded
> > by
> > > bootstrap class loader?I noticed that there are some safety concerns
> > > ,is there any reasons other than that?
> > > Thanks !
> > >
> > >
> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> > >
> > >> Short answer is "no". You'll have to implement osgi loading model
> > >> inside bootstrap classloader. Is it too complex?
> > >>
> > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
> > >> > Hi Pavel.
> > >> >
> > >> > Thanks.
> > >> > Yes ,that's right .My question is whether there is a way to load the
> > >> system
> > >> > class by class loader other than the bootstrap class loader ?
> > >> > If we could load the system class by different loaders other than the
> > >> > bootstrap class loader then there is a chance to make the harmony
> > >> > runtime
> > >> to
> > >> > be osgi-ed.
> > >> > I trying to work on this problem . Do you have any suggestions ?
> > >> >
> > >> >
> > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> > >> >
> > >> >> Tian,
> > >> >> System classes are all loaded with bootstrap classloader. It is
> > >> >> written in C++ and is located in
> > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
> > >> >>
> > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
> > >> >> > Hi all
> > >> >> > I have a question about the classloading in the drlvm.
> > >> >> >
> > >> >> > I know that there are kernel library inside the drlvm such as
> > >> >> > java.lang.classloader, which enclose the the systemclassloader. And
> > >> this
> > >> >> > class is loaded and used in the process of creating VM .
> > >> >> > While the systemclassloader is a subtype of urlclassloader which is
> > >> >> > in
> > >> >> the
> > >> >> > "luni" module.So does the JNI_CreateJavaVM
> > >> >> > also load the urlclassloader in the boot procedure of vm ?(I failed
> > >> >> > to
> > >> >> > search related code in the source code of drlvm).
> > >> >> > If so , when ?Before or after the jni available ?
> > >> >> > Since I am trying to implement the osgi on harmony and the osgi
> > works
> > >> >> with
> > >> >> > bundles (modules) , I think I need to know the procedure of booting
> > >> and
> > >> >> > loading of class from different modules at the start up time.
> > >> >> > Any clue about this ?Thanks
> > >> >> >
> > >> >> > plus,do we have the source code of java.exe ?Where?
> > >> >> >
> > >> >> > --
> > >> >> > Regards
> > >> >> > Michael Tian
> > >> >> >
> > >> >>
> > >> >
> > >> >
> > >> >
> > >> > --
> > >> > Regards
> > >> > Michael Tian
> > >> >
> > >>
> > >
> > >
> > >
> > > --
> > > Regards
> > > Michael Tian
> > >
> >
>
>
>
> --
> Regards
> Michael Tian
>
> --0016363ba4b87ec6cc046a2f8544--
>
Re: Question about the boot and classloading
Posted by galaxy <ha...@gmail.com>.
FYI,there has been a small modification about the classloader in felix ,see
[
https://issues.apache.org/jira/browse/FELIX-1190?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
2009/6/2 Pavel Pervov <pm...@gmail.com>
> (Noticed it on second read) BTW, getClassLoader() _may_ return null
> for bootstrap class loader. AFAIR, IBM's VME provides Java class
> loader instance for bootstrap class loader.
> The other thing is that for all classes that belongs to class library
> a call to getClassLoader must return the same value (either null or
> real class loader instance). If it's an instance it may then delegate
> to corresponding bundle loaders based on package or class name, but
> the implementation have to make sure that a call to getClassLoader
> returns this top level instance but not the bundle loader to which
> real loading was delegated.
>
> Pavel.
>
> On Tue, Jun 2, 2009 at 12:27 PM, Pavel Pervov <pm...@gmail.com> wrote:
> > Carlos,
> >
> > AFAIU, the idea was to move harmony class library to use OSGi style
> > (per-bundle) loading. That's why it is necessary to stuff it into
> > DRLVM.
> >
> > WBR,
> > Pavel.
> >
> > 2009/6/2 Carlos Torrão <ca...@gmail.com>:
> >> The eclipse equinox implements the OSGi Framework only in Java, since
> the
> >> file comes in .jar file and can run in every JVM.
> >>
> >> I tried to start the OSGi implementation of equinox with Harmony and it
> >> worked fine.
> >>
> >> java -jar org.eclipse.osgi_3.4.0.v20080605-1900 -console
> >>
> >> Don't understand why do you need to change this JVM to implement OSGi...
> >>
> >> Best regards,
> >> Carlos Torrão
> >>
> >>
> >> 2009/5/20 Pavel Pervov <pm...@gmail.com>
> >>
> >>> Sure. I've posted from mobile, and my multitap betrayed me. Thanks,
> Mark.
> >>>
> >>> 2009/5/20, Mark Hindess <ma...@googlemail.com>:
> >>> >
> >>> > In message <
> e0f125db0905190627l72e6894fuc6904e92f37c27d4@mail.gmail.com
> >>> >,
> >>> > Pavel Pervov writes:
> >>> >>
> >>> >> Please, read this nice presentation [1] on osgi vs classic class
> >>> loading.
> >>> >> [1]
> >>> >>
> >>>
> http://www.martinliqert.com/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
> >>> >
> >>> > I assume you mean:
> >>> >
> >>> >
> >>> >
> >>>
> http://www.martinlippert.org/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
> >>> >
> >>> > -Mark.
> >>> >
> >>> >> 2009/5/19, tian galaxy <ha...@gmail.com>:
> >>> >> > XiaoFeng , Mark
> >>> >> > Thanks for your help ,very valuable to me.
> >>> >> > I think I need to research more on this .Much more complex than I
> >>> >> > thought
> >>> >> > previously.
> >>> >> >
> >>> >> >
> >>> >> > Regard
> >>> >> > Tian
> >>> >> >
> >>> >> > 2009/5/19 Xiao-Feng Li <xi...@gmail.com>
> >>> >> >
> >>> >> >> On Tue, May 19, 2009 at 6:41 PM, Mark Hindess
> >>> >> >> <ma...@googlemail.com> wrote:
> >>> >> >> >
> >>> >> >> > In message
> >>> >> >> > <df...@mail.gmail.com>,
> >>> >> >> tian
> >>> >> >> > galaxy writes:
> >>> >> >> >>
> >>> >> >> >> Hindess .Thanks for the help ! I realized that this far more
> >>> complex
> >>> >> >> than I
> >>> >> >> >> thought before .
> >>> >> >> >> So I think I need a deeper look into both osgi and harmony .
> >>> >> >> >> Here are several things I don't qiute understand and I noted
> them
> >>> >> >> below.May
> >>> >> >> >> be it's because I am not quite familiar with the low level ,
> >>> >> >> classloading
> >>> >> >> >> details .
> >>> >> >> >> thanks!
> >>> >> >> >>
> >>> >> >> >> 2009/5/19 Mark Hindess <ma...@googlemail.com>
> >>> >> >> >> >
> >>> >> >> >> > In message <
> >>> >> >> dff214c70905180610w407e3bd4h5baa319729c1fc55@mail.gmail.com>,
> >>> >> >> >> > tian galaxy writes:
> >>> >> >> >> > >
> >>> >> >> >> > > OK ,thanks .Seems the minimal class set has been defined
> by
> >>> the
> >>> >> >> osgi.
> >>> >> >> >> >
> >>> >> >> >> > Not sure how this helps though. The OSGi Minimum Execution
> >>> >> >> Environment
> >>> >> >> >> > says what is theoretically the minimum required to run OSGi.
> >>> What
> >>> >> >> >> > we
> >>> >> >> >> > need to concern ourselves with is the *practical* minimum
> and
> >>> that
> >>> >> >> >> > really depends on our implementation details.
> >>> >> >> >> >
> >>> >> >> >> > I don't think that we should implement OSGi in the VM.
> Instead
> >>> >> >> >> > the
> >>> >> >> >> > existing bootstrap classloader should load the OSGi
> framework
> >>> >> >> >> > (with
> >>> >> >> >> > a unique classloader)
> >>> >> >> >>
> >>> >> >> >> If we load the osgi with the bootstrap class loader , why
> comes a
> >>> >> >> >> unique
> >>> >> >> >> class loader?
> >>> >> >> >
> >>> >> >> > It isn't necessary but I think it is useful to use a separate
> >>> >> >> > classloader for the OSGi framework so that we can isolate the
> >>> classes
> >>> >> >> > use by the VM's OSGi framework and avoid polluting the
> namespace.
> >>> >> >> >
> >>> >> >> >> Do you mean the bootstrap class loader should delegate the
> loading
> >>> >> >> >> to
> >>> >> >> >> the 'unique class loader '?
> >>> >> >> >
> >>> >> >> > Yes.
> >>> >> >> >
> >>> >> >> >> > and the system classes (with a "temporary" classloader).
> >>> >> >> >>
> >>> >> >> >> Again ,the relation between temporary and bootstrap
> classloder?
> >>> And
> >>> >> >> >> why temporary ?
> >>> >> >> >
> >>> >> >> > Temporary because until the OSGi framework is up you wont know
> >>> which
> >>> >> >> > bundle the classes belong to and thus wont know which bundle
> >>> >> >> > classloader
> >>> >> >> > the classes should belong to. Alternatively, I suppose you
> could
> >>> >> >> > implement minimal support for reading OSGi headers from
> manifests
> >>> >> >> > in the VM so that you could assign classes to what would become
> a
> >>> >> >> > bundle
> >>> >> >> > classloader when the framework is up.
> >>> >> >> >
> >>> >> >> > -Mark.
> >>> >> >>
> >>> >> >>
> >>> >> >> This makes sense to me. The VM simply grabs in all the stuff "as
> >>> >> >> usual" including the OSGi framework, then sort them out according
> to
> >>> >> >> the bundles' definitions.
> >>> >> >>
> >>> >> >> It could be VM-neutral, because it is the VM's own business to
> take
> >>> >> >> care of its loaded classes. A callback interface OSGI_ready() can
> >>> >> >> inform the VM to tidy up the classes loaded for OSGi (or before
> it is
> >>> >> >> ready).
> >>> >> >>
> >>> >> >> Thanks,
> >>> >> >> xiaofeng
> >>> >> >>
> >>> >> >>
> >>> >> >> >> > Once the OSGi framework is configured the system classes
> need
> >>> to
> >>> >> >> >> > be
> >>> >> >> >> > moved to the correct classloader for the OSGi bundle to
> which
> >>> they
> >>> >> >> >> > belong.
> >>> >> >> >> >
> >>> >> >> >> > This means that during the initial starting-OSGi-framework
> phase
> >>> >> >> >> > the OSGi bundle import/exports will not be enforced but,
> other
> >>> >> >> >> > than
> >>> >> >> >> > implementing OSGi in the VM, I don't see how to avoid this.
> >>> >> >> >> >
> >>> >> >> >> > The multiplicity of bootstrap classloaders still needs to be
> >>> >> >> >> > hidden
> >>> >> >> >> > since the API demands that getClassLoader should return null
> for
> >>> >> >> >> > the
> >>> >> >> >> > bootstrap classloader(s).
> >>> >> >> >> >
> >>> >> >> >> > The biggest problem is probably how to implement this as
> >>> >> >> VM-independent
> >>> >> >> >> > API such that a VM wanting to implement OSGi had to provide
> only
> >>> a
> >>> >> >> >> > minimal C/Java interface in order to gain OSGi support.
> >>> >> >> >> >
> >>> >> >> >> > Regards,
> >>> >> >> >> > Mark.
> >>> >> >> >> >
> >>> >> >> >> > > I will look more closely on this problems and let you know
> if
> >>> >> >> >> > > there
> >>> >> >> some
> >>> >> >> >> > > progresses made.
> >>> >> >> >> > > Thanks a lot !
> >>> >> >> >> >
> >>> >> >> >> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >>> >> >> >> > >
> >>> >> >> >> > > > I do not know osgi model in detail, but what minimal set
> of
> >>> >> >> classes is
> >>> >> >> >> > > > needed to start osgi model itself? Then we could
> delegate to
> >>> >> >> "system"
> >>> >> >> >> > > > bundle loader from bootstrap classloader.
> >>> >> >> >> > > >
> >>> >> >> >> > > > 2009/5/18, tian galaxy <ha...@gmail.com>:
> >>> >> >> >> > > > > Yes , implement osgi loading model in there is too
> >>> complex.
> >>> >> >> >> > > > >
> >>> >> >> >> > > > > We know some modules are more important than others ,
> >>> >> >> >> > > > > performing
> >>> >> >> some
> >>> >> >> >> > > > > fundamental , basic functions .
> >>> >> >> >> > > > > Is it possible to only load these more" basic "
> modules
> >>> with
> >>> >> >> >> > bootstrap
> >>> >> >> >> > > > class
> >>> >> >> >> > > > > loader and make the other modules work the osgi
> bundle?
> >>> >> >> >> > > > > Actually I don't quite understand why system classes
> could
> >>> >> >> >> > > > > only
> >>> >> >> be
> >>> >> >> >> > loaded
> >>> >> >> >> > > > by
> >>> >> >> >> > > > > bootstrap class loader?I noticed that there are some
> >>> safety
> >>> >> >> concerns
> >>> >> >> >> > > > > ,is there any reasons other than that?
> >>> >> >> >> > > > > Thanks !
> >>> >> >> >> > > > >
> >>> >> >> >> > > > >
> >>> >> >> >> > > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >>> >> >> >> > > > >
> >>> >> >> >> > > > >> Short answer is "no". You'll have to implement osgi
> >>> loading
> >>> >> >> model
> >>> >> >> >> > > > >> inside bootstrap classloader. Is it too complex?
> >>> >> >> >> > > > >>
> >>> >> >> >> > > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
> >>> >> >> >> > > > >> > Hi Pavel.
> >>> >> >> >> > > > >> >
> >>> >> >> >> > > > >> > Thanks.
> >>> >> >> >> > > > >> > Yes ,that's right .My question is whether there is
> a
> >>> way
> >>> >> >> >> > > > >> > to
> >>> >> >> load
> >>> >> >> >> > the
> >>> >> >> >> > > > >> system
> >>> >> >> >> > > > >> > class by class loader other than the bootstrap
> class
> >>> >> >> >> > > > >> > loader
> >>> >> >> ?
> >>> >> >> >> > > > >> > If we could load the system class by different
> loaders
> >>> >> >> >> > > > >> > other
> >>> >> >> than
> >>> >> >> >> > the
> >>> >> >> >> > > > >> > bootstrap class loader then there is a chance to
> make
> >>> the
> >>> >> >> harmony
> >>> >> >> >> > > > >> > runtime
> >>> >> >> >> > > > >> to
> >>> >> >> >> > > > >> > be osgi-ed.
> >>> >> >> >> > > > >> > I trying to work on this problem . Do you have any
> >>> >> >> suggestions ?
> >>> >> >> >> > > > >> >
> >>> >> >> >> > > > >> >
> >>> >> >> >> > > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >>> >> >> >> > > > >> >
> >>> >> >> >> > > > >> >> Tian,
> >>> >> >> >> > > > >> >> System classes are all loaded with bootstrap
> >>> >> >> >> > > > >> >> classloader.
> >>> >> >> >> > > > >> >> It
> >>> >> >> is
> >>> >> >> >> > > > >> >> written in C++ and is located in
> >>> >> >> >> > > > >> >>
> working_vm/vm/vmcore/src/class_support/classloader.cpp
> >>> >> >> >> > > > >> >>
> >>> >> >> >> > > > >> >> 2009/5/17, tian galaxy <harmonymail.ty@gmail.com
> >:
> >>> >> >> >> > > > >> >> > Hi all
> >>> >> >> >> > > > >> >> > I have a question about the classloading in the
> >>> drlvm.
> >>> >> >> >> > > > >> >> >
> >>> >> >> >> > > > >> >> > I know that there are kernel library inside the
> >>> drlvm
> >>> >> >> >> > > > >> >> > such
> >>> >> >> as
> >>> >> >> >> > > > >> >> > java.lang.classloader, which enclose the the
> >>> >> >> systemclassloader.
> >>> >> >> >> > And
> >>> >> >> >> > > > >> this
> >>> >> >> >> > > > >> >> > class is loaded and used in the process of
> creating
> >>> VM
> >>> >> >> >> > > > >> >> > .
> >>> >> >> >> > > > >> >> > While the systemclassloader is a subtype of
> >>> >> >> >> > > > >> >> > urlclassloader
> >>> >> >> >> > which is
> >>> >> >> >> > > > >> >> > in
> >>> >> >> >> > > > >> >> the
> >>> >> >> >> > > > >> >> > "luni" module.So does the JNI_CreateJavaVM
> >>> >> >> >> > > > >> >> > also load the urlclassloader in the boot
> procedure
> >>> of
> >>> >> >> >> > > > >> >> > vm
> >>> >> >> ?(I
> >>> >> >> >> > failed
> >>> >> >> >> > > > >> >> > to
> >>> >> >> >> > > > >> >> > search related code in the source code of
> drlvm).
> >>> >> >> >> > > > >> >> > If so , when ?Before or after the jni available
> ?
> >>> >> >> >> > > > >> >> > Since I am trying to implement the osgi on
> harmony
> >>> and
> >>> >> >> >> > > > >> >> > the
> >>> >> >> osgi
> >>> >> >> >> > > > works
> >>> >> >> >> > > > >> >> with
> >>> >> >> >> > > > >> >> > bundles (modules) , I think I need to know the
> >>> >> >> >> > > > >> >> > procedure
> >>> >> >> of
> >>> >> >> >> > booting
> >>> >> >> >> > > > >> and
> >>> >> >> >> > > > >> >> > loading of class from different modules at the
> start
> >>> >> >> >> > > > >> >> > up
> >>> >> >> time.
> >>> >> >> >> > > > >> >> > Any clue about this ?Thanks
> >>> >> >> >> > > > >> >> >
> >>> >> >> >> > > > >> >> > plus,do we have the source code of java.exe
> ?Where?
> >>> >> >> >
> >>> >> >> >
> >>> >> >> >
> >>> >> >>
> >>> >> >>
> >>> >> >>
> >>> >> >> --
> >>> >> >> http://people.apache.org/~xli <http://people.apache.org/%7Exli>
> >>> >> >>
> >>> >> >
> >>> >> >
> >>> >> >
> >>> >> > --
> >>> >> > Regards
> >>> >> > Michael Tian
> >>> >> >
> >>> >>
> >>> >
> >>> >
> >>> >
> >>>
> >>
> >
>
--
regards
Tian
Re: Question about the boot and classloading
Posted by Pavel Pervov <pm...@gmail.com>.
(Noticed it on second read) BTW, getClassLoader() _may_ return null
for bootstrap class loader. AFAIR, IBM's VME provides Java class
loader instance for bootstrap class loader.
The other thing is that for all classes that belongs to class library
a call to getClassLoader must return the same value (either null or
real class loader instance). If it's an instance it may then delegate
to corresponding bundle loaders based on package or class name, but
the implementation have to make sure that a call to getClassLoader
returns this top level instance but not the bundle loader to which
real loading was delegated.
Pavel.
On Tue, Jun 2, 2009 at 12:27 PM, Pavel Pervov <pm...@gmail.com> wrote:
> Carlos,
>
> AFAIU, the idea was to move harmony class library to use OSGi style
> (per-bundle) loading. That's why it is necessary to stuff it into
> DRLVM.
>
> WBR,
> Pavel.
>
> 2009/6/2 Carlos Torrão <ca...@gmail.com>:
>> The eclipse equinox implements the OSGi Framework only in Java, since the
>> file comes in .jar file and can run in every JVM.
>>
>> I tried to start the OSGi implementation of equinox with Harmony and it
>> worked fine.
>>
>> java -jar org.eclipse.osgi_3.4.0.v20080605-1900 -console
>>
>> Don't understand why do you need to change this JVM to implement OSGi...
>>
>> Best regards,
>> Carlos Torrão
>>
>>
>> 2009/5/20 Pavel Pervov <pm...@gmail.com>
>>
>>> Sure. I've posted from mobile, and my multitap betrayed me. Thanks, Mark.
>>>
>>> 2009/5/20, Mark Hindess <ma...@googlemail.com>:
>>> >
>>> > In message <e0f125db0905190627l72e6894fuc6904e92f37c27d4@mail.gmail.com
>>> >,
>>> > Pavel Pervov writes:
>>> >>
>>> >> Please, read this nice presentation [1] on osgi vs classic class
>>> loading.
>>> >> [1]
>>> >>
>>> http://www.martinliqert.com/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
>>> >
>>> > I assume you mean:
>>> >
>>> >
>>> >
>>> http://www.martinlippert.org/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
>>> >
>>> > -Mark.
>>> >
>>> >> 2009/5/19, tian galaxy <ha...@gmail.com>:
>>> >> > XiaoFeng , Mark
>>> >> > Thanks for your help ,very valuable to me.
>>> >> > I think I need to research more on this .Much more complex than I
>>> >> > thought
>>> >> > previously.
>>> >> >
>>> >> >
>>> >> > Regard
>>> >> > Tian
>>> >> >
>>> >> > 2009/5/19 Xiao-Feng Li <xi...@gmail.com>
>>> >> >
>>> >> >> On Tue, May 19, 2009 at 6:41 PM, Mark Hindess
>>> >> >> <ma...@googlemail.com> wrote:
>>> >> >> >
>>> >> >> > In message
>>> >> >> > <df...@mail.gmail.com>,
>>> >> >> tian
>>> >> >> > galaxy writes:
>>> >> >> >>
>>> >> >> >> Hindess .Thanks for the help ! I realized that this far more
>>> complex
>>> >> >> than I
>>> >> >> >> thought before .
>>> >> >> >> So I think I need a deeper look into both osgi and harmony .
>>> >> >> >> Here are several things I don't qiute understand and I noted them
>>> >> >> below.May
>>> >> >> >> be it's because I am not quite familiar with the low level ,
>>> >> >> classloading
>>> >> >> >> details .
>>> >> >> >> thanks!
>>> >> >> >>
>>> >> >> >> 2009/5/19 Mark Hindess <ma...@googlemail.com>
>>> >> >> >> >
>>> >> >> >> > In message <
>>> >> >> dff214c70905180610w407e3bd4h5baa319729c1fc55@mail.gmail.com>,
>>> >> >> >> > tian galaxy writes:
>>> >> >> >> > >
>>> >> >> >> > > OK ,thanks .Seems the minimal class set has been defined by
>>> the
>>> >> >> osgi.
>>> >> >> >> >
>>> >> >> >> > Not sure how this helps though. The OSGi Minimum Execution
>>> >> >> Environment
>>> >> >> >> > says what is theoretically the minimum required to run OSGi.
>>> What
>>> >> >> >> > we
>>> >> >> >> > need to concern ourselves with is the *practical* minimum and
>>> that
>>> >> >> >> > really depends on our implementation details.
>>> >> >> >> >
>>> >> >> >> > I don't think that we should implement OSGi in the VM. Instead
>>> >> >> >> > the
>>> >> >> >> > existing bootstrap classloader should load the OSGi framework
>>> >> >> >> > (with
>>> >> >> >> > a unique classloader)
>>> >> >> >>
>>> >> >> >> If we load the osgi with the bootstrap class loader , why comes a
>>> >> >> >> unique
>>> >> >> >> class loader?
>>> >> >> >
>>> >> >> > It isn't necessary but I think it is useful to use a separate
>>> >> >> > classloader for the OSGi framework so that we can isolate the
>>> classes
>>> >> >> > use by the VM's OSGi framework and avoid polluting the namespace.
>>> >> >> >
>>> >> >> >> Do you mean the bootstrap class loader should delegate the loading
>>> >> >> >> to
>>> >> >> >> the 'unique class loader '?
>>> >> >> >
>>> >> >> > Yes.
>>> >> >> >
>>> >> >> >> > and the system classes (with a "temporary" classloader).
>>> >> >> >>
>>> >> >> >> Again ,the relation between temporary and bootstrap classloder?
>>> And
>>> >> >> >> why temporary ?
>>> >> >> >
>>> >> >> > Temporary because until the OSGi framework is up you wont know
>>> which
>>> >> >> > bundle the classes belong to and thus wont know which bundle
>>> >> >> > classloader
>>> >> >> > the classes should belong to. Alternatively, I suppose you could
>>> >> >> > implement minimal support for reading OSGi headers from manifests
>>> >> >> > in the VM so that you could assign classes to what would become a
>>> >> >> > bundle
>>> >> >> > classloader when the framework is up.
>>> >> >> >
>>> >> >> > -Mark.
>>> >> >>
>>> >> >>
>>> >> >> This makes sense to me. The VM simply grabs in all the stuff "as
>>> >> >> usual" including the OSGi framework, then sort them out according to
>>> >> >> the bundles' definitions.
>>> >> >>
>>> >> >> It could be VM-neutral, because it is the VM's own business to take
>>> >> >> care of its loaded classes. A callback interface OSGI_ready() can
>>> >> >> inform the VM to tidy up the classes loaded for OSGi (or before it is
>>> >> >> ready).
>>> >> >>
>>> >> >> Thanks,
>>> >> >> xiaofeng
>>> >> >>
>>> >> >>
>>> >> >> >> > Once the OSGi framework is configured the system classes need
>>> to
>>> >> >> >> > be
>>> >> >> >> > moved to the correct classloader for the OSGi bundle to which
>>> they
>>> >> >> >> > belong.
>>> >> >> >> >
>>> >> >> >> > This means that during the initial starting-OSGi-framework phase
>>> >> >> >> > the OSGi bundle import/exports will not be enforced but, other
>>> >> >> >> > than
>>> >> >> >> > implementing OSGi in the VM, I don't see how to avoid this.
>>> >> >> >> >
>>> >> >> >> > The multiplicity of bootstrap classloaders still needs to be
>>> >> >> >> > hidden
>>> >> >> >> > since the API demands that getClassLoader should return null for
>>> >> >> >> > the
>>> >> >> >> > bootstrap classloader(s).
>>> >> >> >> >
>>> >> >> >> > The biggest problem is probably how to implement this as
>>> >> >> VM-independent
>>> >> >> >> > API such that a VM wanting to implement OSGi had to provide only
>>> a
>>> >> >> >> > minimal C/Java interface in order to gain OSGi support.
>>> >> >> >> >
>>> >> >> >> > Regards,
>>> >> >> >> > Mark.
>>> >> >> >> >
>>> >> >> >> > > I will look more closely on this problems and let you know if
>>> >> >> >> > > there
>>> >> >> some
>>> >> >> >> > > progresses made.
>>> >> >> >> > > Thanks a lot !
>>> >> >> >> >
>>> >> >> >> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>>> >> >> >> > >
>>> >> >> >> > > > I do not know osgi model in detail, but what minimal set of
>>> >> >> classes is
>>> >> >> >> > > > needed to start osgi model itself? Then we could delegate to
>>> >> >> "system"
>>> >> >> >> > > > bundle loader from bootstrap classloader.
>>> >> >> >> > > >
>>> >> >> >> > > > 2009/5/18, tian galaxy <ha...@gmail.com>:
>>> >> >> >> > > > > Yes , implement osgi loading model in there is too
>>> complex.
>>> >> >> >> > > > >
>>> >> >> >> > > > > We know some modules are more important than others ,
>>> >> >> >> > > > > performing
>>> >> >> some
>>> >> >> >> > > > > fundamental , basic functions .
>>> >> >> >> > > > > Is it possible to only load these more" basic " modules
>>> with
>>> >> >> >> > bootstrap
>>> >> >> >> > > > class
>>> >> >> >> > > > > loader and make the other modules work the osgi bundle?
>>> >> >> >> > > > > Actually I don't quite understand why system classes could
>>> >> >> >> > > > > only
>>> >> >> be
>>> >> >> >> > loaded
>>> >> >> >> > > > by
>>> >> >> >> > > > > bootstrap class loader?I noticed that there are some
>>> safety
>>> >> >> concerns
>>> >> >> >> > > > > ,is there any reasons other than that?
>>> >> >> >> > > > > Thanks !
>>> >> >> >> > > > >
>>> >> >> >> > > > >
>>> >> >> >> > > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>>> >> >> >> > > > >
>>> >> >> >> > > > >> Short answer is "no". You'll have to implement osgi
>>> loading
>>> >> >> model
>>> >> >> >> > > > >> inside bootstrap classloader. Is it too complex?
>>> >> >> >> > > > >>
>>> >> >> >> > > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
>>> >> >> >> > > > >> > Hi Pavel.
>>> >> >> >> > > > >> >
>>> >> >> >> > > > >> > Thanks.
>>> >> >> >> > > > >> > Yes ,that's right .My question is whether there is a
>>> way
>>> >> >> >> > > > >> > to
>>> >> >> load
>>> >> >> >> > the
>>> >> >> >> > > > >> system
>>> >> >> >> > > > >> > class by class loader other than the bootstrap class
>>> >> >> >> > > > >> > loader
>>> >> >> ?
>>> >> >> >> > > > >> > If we could load the system class by different loaders
>>> >> >> >> > > > >> > other
>>> >> >> than
>>> >> >> >> > the
>>> >> >> >> > > > >> > bootstrap class loader then there is a chance to make
>>> the
>>> >> >> harmony
>>> >> >> >> > > > >> > runtime
>>> >> >> >> > > > >> to
>>> >> >> >> > > > >> > be osgi-ed.
>>> >> >> >> > > > >> > I trying to work on this problem . Do you have any
>>> >> >> suggestions ?
>>> >> >> >> > > > >> >
>>> >> >> >> > > > >> >
>>> >> >> >> > > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>>> >> >> >> > > > >> >
>>> >> >> >> > > > >> >> Tian,
>>> >> >> >> > > > >> >> System classes are all loaded with bootstrap
>>> >> >> >> > > > >> >> classloader.
>>> >> >> >> > > > >> >> It
>>> >> >> is
>>> >> >> >> > > > >> >> written in C++ and is located in
>>> >> >> >> > > > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
>>> >> >> >> > > > >> >>
>>> >> >> >> > > > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
>>> >> >> >> > > > >> >> > Hi all
>>> >> >> >> > > > >> >> > I have a question about the classloading in the
>>> drlvm.
>>> >> >> >> > > > >> >> >
>>> >> >> >> > > > >> >> > I know that there are kernel library inside the
>>> drlvm
>>> >> >> >> > > > >> >> > such
>>> >> >> as
>>> >> >> >> > > > >> >> > java.lang.classloader, which enclose the the
>>> >> >> systemclassloader.
>>> >> >> >> > And
>>> >> >> >> > > > >> this
>>> >> >> >> > > > >> >> > class is loaded and used in the process of creating
>>> VM
>>> >> >> >> > > > >> >> > .
>>> >> >> >> > > > >> >> > While the systemclassloader is a subtype of
>>> >> >> >> > > > >> >> > urlclassloader
>>> >> >> >> > which is
>>> >> >> >> > > > >> >> > in
>>> >> >> >> > > > >> >> the
>>> >> >> >> > > > >> >> > "luni" module.So does the JNI_CreateJavaVM
>>> >> >> >> > > > >> >> > also load the urlclassloader in the boot procedure
>>> of
>>> >> >> >> > > > >> >> > vm
>>> >> >> ?(I
>>> >> >> >> > failed
>>> >> >> >> > > > >> >> > to
>>> >> >> >> > > > >> >> > search related code in the source code of drlvm).
>>> >> >> >> > > > >> >> > If so , when ?Before or after the jni available ?
>>> >> >> >> > > > >> >> > Since I am trying to implement the osgi on harmony
>>> and
>>> >> >> >> > > > >> >> > the
>>> >> >> osgi
>>> >> >> >> > > > works
>>> >> >> >> > > > >> >> with
>>> >> >> >> > > > >> >> > bundles (modules) , I think I need to know the
>>> >> >> >> > > > >> >> > procedure
>>> >> >> of
>>> >> >> >> > booting
>>> >> >> >> > > > >> and
>>> >> >> >> > > > >> >> > loading of class from different modules at the start
>>> >> >> >> > > > >> >> > up
>>> >> >> time.
>>> >> >> >> > > > >> >> > Any clue about this ?Thanks
>>> >> >> >> > > > >> >> >
>>> >> >> >> > > > >> >> > plus,do we have the source code of java.exe ?Where?
>>> >> >> >
>>> >> >> >
>>> >> >> >
>>> >> >>
>>> >> >>
>>> >> >>
>>> >> >> --
>>> >> >> http://people.apache.org/~xli <http://people.apache.org/%7Exli>
>>> >> >>
>>> >> >
>>> >> >
>>> >> >
>>> >> > --
>>> >> > Regards
>>> >> > Michael Tian
>>> >> >
>>> >>
>>> >
>>> >
>>> >
>>>
>>
>
Re: Question about the boot and classloading
Posted by Pavel Pervov <pm...@gmail.com>.
Carlos,
AFAIU, the idea was to move harmony class library to use OSGi style
(per-bundle) loading. That's why it is necessary to stuff it into
DRLVM.
WBR,
Pavel.
2009/6/2 Carlos Torrão <ca...@gmail.com>:
> The eclipse equinox implements the OSGi Framework only in Java, since the
> file comes in .jar file and can run in every JVM.
>
> I tried to start the OSGi implementation of equinox with Harmony and it
> worked fine.
>
> java -jar org.eclipse.osgi_3.4.0.v20080605-1900 -console
>
> Don't understand why do you need to change this JVM to implement OSGi...
>
> Best regards,
> Carlos Torrão
>
>
> 2009/5/20 Pavel Pervov <pm...@gmail.com>
>
>> Sure. I've posted from mobile, and my multitap betrayed me. Thanks, Mark.
>>
>> 2009/5/20, Mark Hindess <ma...@googlemail.com>:
>> >
>> > In message <e0f125db0905190627l72e6894fuc6904e92f37c27d4@mail.gmail.com
>> >,
>> > Pavel Pervov writes:
>> >>
>> >> Please, read this nice presentation [1] on osgi vs classic class
>> loading.
>> >> [1]
>> >>
>> http://www.martinliqert.com/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
>> >
>> > I assume you mean:
>> >
>> >
>> >
>> http://www.martinlippert.org/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
>> >
>> > -Mark.
>> >
>> >> 2009/5/19, tian galaxy <ha...@gmail.com>:
>> >> > XiaoFeng , Mark
>> >> > Thanks for your help ,very valuable to me.
>> >> > I think I need to research more on this .Much more complex than I
>> >> > thought
>> >> > previously.
>> >> >
>> >> >
>> >> > Regard
>> >> > Tian
>> >> >
>> >> > 2009/5/19 Xiao-Feng Li <xi...@gmail.com>
>> >> >
>> >> >> On Tue, May 19, 2009 at 6:41 PM, Mark Hindess
>> >> >> <ma...@googlemail.com> wrote:
>> >> >> >
>> >> >> > In message
>> >> >> > <df...@mail.gmail.com>,
>> >> >> tian
>> >> >> > galaxy writes:
>> >> >> >>
>> >> >> >> Hindess .Thanks for the help ! I realized that this far more
>> complex
>> >> >> than I
>> >> >> >> thought before .
>> >> >> >> So I think I need a deeper look into both osgi and harmony .
>> >> >> >> Here are several things I don't qiute understand and I noted them
>> >> >> below.May
>> >> >> >> be it's because I am not quite familiar with the low level ,
>> >> >> classloading
>> >> >> >> details .
>> >> >> >> thanks!
>> >> >> >>
>> >> >> >> 2009/5/19 Mark Hindess <ma...@googlemail.com>
>> >> >> >> >
>> >> >> >> > In message <
>> >> >> dff214c70905180610w407e3bd4h5baa319729c1fc55@mail.gmail.com>,
>> >> >> >> > tian galaxy writes:
>> >> >> >> > >
>> >> >> >> > > OK ,thanks .Seems the minimal class set has been defined by
>> the
>> >> >> osgi.
>> >> >> >> >
>> >> >> >> > Not sure how this helps though. The OSGi Minimum Execution
>> >> >> Environment
>> >> >> >> > says what is theoretically the minimum required to run OSGi.
>> What
>> >> >> >> > we
>> >> >> >> > need to concern ourselves with is the *practical* minimum and
>> that
>> >> >> >> > really depends on our implementation details.
>> >> >> >> >
>> >> >> >> > I don't think that we should implement OSGi in the VM. Instead
>> >> >> >> > the
>> >> >> >> > existing bootstrap classloader should load the OSGi framework
>> >> >> >> > (with
>> >> >> >> > a unique classloader)
>> >> >> >>
>> >> >> >> If we load the osgi with the bootstrap class loader , why comes a
>> >> >> >> unique
>> >> >> >> class loader?
>> >> >> >
>> >> >> > It isn't necessary but I think it is useful to use a separate
>> >> >> > classloader for the OSGi framework so that we can isolate the
>> classes
>> >> >> > use by the VM's OSGi framework and avoid polluting the namespace.
>> >> >> >
>> >> >> >> Do you mean the bootstrap class loader should delegate the loading
>> >> >> >> to
>> >> >> >> the 'unique class loader '?
>> >> >> >
>> >> >> > Yes.
>> >> >> >
>> >> >> >> > and the system classes (with a "temporary" classloader).
>> >> >> >>
>> >> >> >> Again ,the relation between temporary and bootstrap classloder?
>> And
>> >> >> >> why temporary ?
>> >> >> >
>> >> >> > Temporary because until the OSGi framework is up you wont know
>> which
>> >> >> > bundle the classes belong to and thus wont know which bundle
>> >> >> > classloader
>> >> >> > the classes should belong to. Alternatively, I suppose you could
>> >> >> > implement minimal support for reading OSGi headers from manifests
>> >> >> > in the VM so that you could assign classes to what would become a
>> >> >> > bundle
>> >> >> > classloader when the framework is up.
>> >> >> >
>> >> >> > -Mark.
>> >> >>
>> >> >>
>> >> >> This makes sense to me. The VM simply grabs in all the stuff "as
>> >> >> usual" including the OSGi framework, then sort them out according to
>> >> >> the bundles' definitions.
>> >> >>
>> >> >> It could be VM-neutral, because it is the VM's own business to take
>> >> >> care of its loaded classes. A callback interface OSGI_ready() can
>> >> >> inform the VM to tidy up the classes loaded for OSGi (or before it is
>> >> >> ready).
>> >> >>
>> >> >> Thanks,
>> >> >> xiaofeng
>> >> >>
>> >> >>
>> >> >> >> > Once the OSGi framework is configured the system classes need
>> to
>> >> >> >> > be
>> >> >> >> > moved to the correct classloader for the OSGi bundle to which
>> they
>> >> >> >> > belong.
>> >> >> >> >
>> >> >> >> > This means that during the initial starting-OSGi-framework phase
>> >> >> >> > the OSGi bundle import/exports will not be enforced but, other
>> >> >> >> > than
>> >> >> >> > implementing OSGi in the VM, I don't see how to avoid this.
>> >> >> >> >
>> >> >> >> > The multiplicity of bootstrap classloaders still needs to be
>> >> >> >> > hidden
>> >> >> >> > since the API demands that getClassLoader should return null for
>> >> >> >> > the
>> >> >> >> > bootstrap classloader(s).
>> >> >> >> >
>> >> >> >> > The biggest problem is probably how to implement this as
>> >> >> VM-independent
>> >> >> >> > API such that a VM wanting to implement OSGi had to provide only
>> a
>> >> >> >> > minimal C/Java interface in order to gain OSGi support.
>> >> >> >> >
>> >> >> >> > Regards,
>> >> >> >> > Mark.
>> >> >> >> >
>> >> >> >> > > I will look more closely on this problems and let you know if
>> >> >> >> > > there
>> >> >> some
>> >> >> >> > > progresses made.
>> >> >> >> > > Thanks a lot !
>> >> >> >> >
>> >> >> >> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> >> >> >> > >
>> >> >> >> > > > I do not know osgi model in detail, but what minimal set of
>> >> >> classes is
>> >> >> >> > > > needed to start osgi model itself? Then we could delegate to
>> >> >> "system"
>> >> >> >> > > > bundle loader from bootstrap classloader.
>> >> >> >> > > >
>> >> >> >> > > > 2009/5/18, tian galaxy <ha...@gmail.com>:
>> >> >> >> > > > > Yes , implement osgi loading model in there is too
>> complex.
>> >> >> >> > > > >
>> >> >> >> > > > > We know some modules are more important than others ,
>> >> >> >> > > > > performing
>> >> >> some
>> >> >> >> > > > > fundamental , basic functions .
>> >> >> >> > > > > Is it possible to only load these more" basic " modules
>> with
>> >> >> >> > bootstrap
>> >> >> >> > > > class
>> >> >> >> > > > > loader and make the other modules work the osgi bundle?
>> >> >> >> > > > > Actually I don't quite understand why system classes could
>> >> >> >> > > > > only
>> >> >> be
>> >> >> >> > loaded
>> >> >> >> > > > by
>> >> >> >> > > > > bootstrap class loader?I noticed that there are some
>> safety
>> >> >> concerns
>> >> >> >> > > > > ,is there any reasons other than that?
>> >> >> >> > > > > Thanks !
>> >> >> >> > > > >
>> >> >> >> > > > >
>> >> >> >> > > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> >> >> >> > > > >
>> >> >> >> > > > >> Short answer is "no". You'll have to implement osgi
>> loading
>> >> >> model
>> >> >> >> > > > >> inside bootstrap classloader. Is it too complex?
>> >> >> >> > > > >>
>> >> >> >> > > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
>> >> >> >> > > > >> > Hi Pavel.
>> >> >> >> > > > >> >
>> >> >> >> > > > >> > Thanks.
>> >> >> >> > > > >> > Yes ,that's right .My question is whether there is a
>> way
>> >> >> >> > > > >> > to
>> >> >> load
>> >> >> >> > the
>> >> >> >> > > > >> system
>> >> >> >> > > > >> > class by class loader other than the bootstrap class
>> >> >> >> > > > >> > loader
>> >> >> ?
>> >> >> >> > > > >> > If we could load the system class by different loaders
>> >> >> >> > > > >> > other
>> >> >> than
>> >> >> >> > the
>> >> >> >> > > > >> > bootstrap class loader then there is a chance to make
>> the
>> >> >> harmony
>> >> >> >> > > > >> > runtime
>> >> >> >> > > > >> to
>> >> >> >> > > > >> > be osgi-ed.
>> >> >> >> > > > >> > I trying to work on this problem . Do you have any
>> >> >> suggestions ?
>> >> >> >> > > > >> >
>> >> >> >> > > > >> >
>> >> >> >> > > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> >> >> >> > > > >> >
>> >> >> >> > > > >> >> Tian,
>> >> >> >> > > > >> >> System classes are all loaded with bootstrap
>> >> >> >> > > > >> >> classloader.
>> >> >> >> > > > >> >> It
>> >> >> is
>> >> >> >> > > > >> >> written in C++ and is located in
>> >> >> >> > > > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
>> >> >> >> > > > >> >>
>> >> >> >> > > > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
>> >> >> >> > > > >> >> > Hi all
>> >> >> >> > > > >> >> > I have a question about the classloading in the
>> drlvm.
>> >> >> >> > > > >> >> >
>> >> >> >> > > > >> >> > I know that there are kernel library inside the
>> drlvm
>> >> >> >> > > > >> >> > such
>> >> >> as
>> >> >> >> > > > >> >> > java.lang.classloader, which enclose the the
>> >> >> systemclassloader.
>> >> >> >> > And
>> >> >> >> > > > >> this
>> >> >> >> > > > >> >> > class is loaded and used in the process of creating
>> VM
>> >> >> >> > > > >> >> > .
>> >> >> >> > > > >> >> > While the systemclassloader is a subtype of
>> >> >> >> > > > >> >> > urlclassloader
>> >> >> >> > which is
>> >> >> >> > > > >> >> > in
>> >> >> >> > > > >> >> the
>> >> >> >> > > > >> >> > "luni" module.So does the JNI_CreateJavaVM
>> >> >> >> > > > >> >> > also load the urlclassloader in the boot procedure
>> of
>> >> >> >> > > > >> >> > vm
>> >> >> ?(I
>> >> >> >> > failed
>> >> >> >> > > > >> >> > to
>> >> >> >> > > > >> >> > search related code in the source code of drlvm).
>> >> >> >> > > > >> >> > If so , when ?Before or after the jni available ?
>> >> >> >> > > > >> >> > Since I am trying to implement the osgi on harmony
>> and
>> >> >> >> > > > >> >> > the
>> >> >> osgi
>> >> >> >> > > > works
>> >> >> >> > > > >> >> with
>> >> >> >> > > > >> >> > bundles (modules) , I think I need to know the
>> >> >> >> > > > >> >> > procedure
>> >> >> of
>> >> >> >> > booting
>> >> >> >> > > > >> and
>> >> >> >> > > > >> >> > loading of class from different modules at the start
>> >> >> >> > > > >> >> > up
>> >> >> time.
>> >> >> >> > > > >> >> > Any clue about this ?Thanks
>> >> >> >> > > > >> >> >
>> >> >> >> > > > >> >> > plus,do we have the source code of java.exe ?Where?
>> >> >> >
>> >> >> >
>> >> >> >
>> >> >>
>> >> >>
>> >> >>
>> >> >> --
>> >> >> http://people.apache.org/~xli <http://people.apache.org/%7Exli>
>> >> >>
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > Regards
>> >> > Michael Tian
>> >> >
>> >>
>> >
>> >
>> >
>>
>
Re: Question about the boot and classloading
Posted by Carlos Torrão <ca...@gmail.com>.
The eclipse equinox implements the OSGi Framework only in Java, since the
file comes in .jar file and can run in every JVM.
I tried to start the OSGi implementation of equinox with Harmony and it
worked fine.
java -jar org.eclipse.osgi_3.4.0.v20080605-1900 -console
Don't understand why do you need to change this JVM to implement OSGi...
Best regards,
Carlos Torrão
2009/5/20 Pavel Pervov <pm...@gmail.com>
> Sure. I've posted from mobile, and my multitap betrayed me. Thanks, Mark.
>
> 2009/5/20, Mark Hindess <ma...@googlemail.com>:
> >
> > In message <e0f125db0905190627l72e6894fuc6904e92f37c27d4@mail.gmail.com
> >,
> > Pavel Pervov writes:
> >>
> >> Please, read this nice presentation [1] on osgi vs classic class
> loading.
> >> [1]
> >>
> http://www.martinliqert.com/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
> >
> > I assume you mean:
> >
> >
> >
> http://www.martinlippert.org/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
> >
> > -Mark.
> >
> >> 2009/5/19, tian galaxy <ha...@gmail.com>:
> >> > XiaoFeng , Mark
> >> > Thanks for your help ,very valuable to me.
> >> > I think I need to research more on this .Much more complex than I
> >> > thought
> >> > previously.
> >> >
> >> >
> >> > Regard
> >> > Tian
> >> >
> >> > 2009/5/19 Xiao-Feng Li <xi...@gmail.com>
> >> >
> >> >> On Tue, May 19, 2009 at 6:41 PM, Mark Hindess
> >> >> <ma...@googlemail.com> wrote:
> >> >> >
> >> >> > In message
> >> >> > <df...@mail.gmail.com>,
> >> >> tian
> >> >> > galaxy writes:
> >> >> >>
> >> >> >> Hindess .Thanks for the help ! I realized that this far more
> complex
> >> >> than I
> >> >> >> thought before .
> >> >> >> So I think I need a deeper look into both osgi and harmony .
> >> >> >> Here are several things I don't qiute understand and I noted them
> >> >> below.May
> >> >> >> be it's because I am not quite familiar with the low level ,
> >> >> classloading
> >> >> >> details .
> >> >> >> thanks!
> >> >> >>
> >> >> >> 2009/5/19 Mark Hindess <ma...@googlemail.com>
> >> >> >> >
> >> >> >> > In message <
> >> >> dff214c70905180610w407e3bd4h5baa319729c1fc55@mail.gmail.com>,
> >> >> >> > tian galaxy writes:
> >> >> >> > >
> >> >> >> > > OK ,thanks .Seems the minimal class set has been defined by
> the
> >> >> osgi.
> >> >> >> >
> >> >> >> > Not sure how this helps though. The OSGi Minimum Execution
> >> >> Environment
> >> >> >> > says what is theoretically the minimum required to run OSGi.
> What
> >> >> >> > we
> >> >> >> > need to concern ourselves with is the *practical* minimum and
> that
> >> >> >> > really depends on our implementation details.
> >> >> >> >
> >> >> >> > I don't think that we should implement OSGi in the VM. Instead
> >> >> >> > the
> >> >> >> > existing bootstrap classloader should load the OSGi framework
> >> >> >> > (with
> >> >> >> > a unique classloader)
> >> >> >>
> >> >> >> If we load the osgi with the bootstrap class loader , why comes a
> >> >> >> unique
> >> >> >> class loader?
> >> >> >
> >> >> > It isn't necessary but I think it is useful to use a separate
> >> >> > classloader for the OSGi framework so that we can isolate the
> classes
> >> >> > use by the VM's OSGi framework and avoid polluting the namespace.
> >> >> >
> >> >> >> Do you mean the bootstrap class loader should delegate the loading
> >> >> >> to
> >> >> >> the 'unique class loader '?
> >> >> >
> >> >> > Yes.
> >> >> >
> >> >> >> > and the system classes (with a "temporary" classloader).
> >> >> >>
> >> >> >> Again ,the relation between temporary and bootstrap classloder?
> And
> >> >> >> why temporary ?
> >> >> >
> >> >> > Temporary because until the OSGi framework is up you wont know
> which
> >> >> > bundle the classes belong to and thus wont know which bundle
> >> >> > classloader
> >> >> > the classes should belong to. Alternatively, I suppose you could
> >> >> > implement minimal support for reading OSGi headers from manifests
> >> >> > in the VM so that you could assign classes to what would become a
> >> >> > bundle
> >> >> > classloader when the framework is up.
> >> >> >
> >> >> > -Mark.
> >> >>
> >> >>
> >> >> This makes sense to me. The VM simply grabs in all the stuff "as
> >> >> usual" including the OSGi framework, then sort them out according to
> >> >> the bundles' definitions.
> >> >>
> >> >> It could be VM-neutral, because it is the VM's own business to take
> >> >> care of its loaded classes. A callback interface OSGI_ready() can
> >> >> inform the VM to tidy up the classes loaded for OSGi (or before it is
> >> >> ready).
> >> >>
> >> >> Thanks,
> >> >> xiaofeng
> >> >>
> >> >>
> >> >> >> > Once the OSGi framework is configured the system classes need
> to
> >> >> >> > be
> >> >> >> > moved to the correct classloader for the OSGi bundle to which
> they
> >> >> >> > belong.
> >> >> >> >
> >> >> >> > This means that during the initial starting-OSGi-framework phase
> >> >> >> > the OSGi bundle import/exports will not be enforced but, other
> >> >> >> > than
> >> >> >> > implementing OSGi in the VM, I don't see how to avoid this.
> >> >> >> >
> >> >> >> > The multiplicity of bootstrap classloaders still needs to be
> >> >> >> > hidden
> >> >> >> > since the API demands that getClassLoader should return null for
> >> >> >> > the
> >> >> >> > bootstrap classloader(s).
> >> >> >> >
> >> >> >> > The biggest problem is probably how to implement this as
> >> >> VM-independent
> >> >> >> > API such that a VM wanting to implement OSGi had to provide only
> a
> >> >> >> > minimal C/Java interface in order to gain OSGi support.
> >> >> >> >
> >> >> >> > Regards,
> >> >> >> > Mark.
> >> >> >> >
> >> >> >> > > I will look more closely on this problems and let you know if
> >> >> >> > > there
> >> >> some
> >> >> >> > > progresses made.
> >> >> >> > > Thanks a lot !
> >> >> >> >
> >> >> >> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >> >> >> > >
> >> >> >> > > > I do not know osgi model in detail, but what minimal set of
> >> >> classes is
> >> >> >> > > > needed to start osgi model itself? Then we could delegate to
> >> >> "system"
> >> >> >> > > > bundle loader from bootstrap classloader.
> >> >> >> > > >
> >> >> >> > > > 2009/5/18, tian galaxy <ha...@gmail.com>:
> >> >> >> > > > > Yes , implement osgi loading model in there is too
> complex.
> >> >> >> > > > >
> >> >> >> > > > > We know some modules are more important than others ,
> >> >> >> > > > > performing
> >> >> some
> >> >> >> > > > > fundamental , basic functions .
> >> >> >> > > > > Is it possible to only load these more" basic " modules
> with
> >> >> >> > bootstrap
> >> >> >> > > > class
> >> >> >> > > > > loader and make the other modules work the osgi bundle?
> >> >> >> > > > > Actually I don't quite understand why system classes could
> >> >> >> > > > > only
> >> >> be
> >> >> >> > loaded
> >> >> >> > > > by
> >> >> >> > > > > bootstrap class loader?I noticed that there are some
> safety
> >> >> concerns
> >> >> >> > > > > ,is there any reasons other than that?
> >> >> >> > > > > Thanks !
> >> >> >> > > > >
> >> >> >> > > > >
> >> >> >> > > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >> >> >> > > > >
> >> >> >> > > > >> Short answer is "no". You'll have to implement osgi
> loading
> >> >> model
> >> >> >> > > > >> inside bootstrap classloader. Is it too complex?
> >> >> >> > > > >>
> >> >> >> > > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
> >> >> >> > > > >> > Hi Pavel.
> >> >> >> > > > >> >
> >> >> >> > > > >> > Thanks.
> >> >> >> > > > >> > Yes ,that's right .My question is whether there is a
> way
> >> >> >> > > > >> > to
> >> >> load
> >> >> >> > the
> >> >> >> > > > >> system
> >> >> >> > > > >> > class by class loader other than the bootstrap class
> >> >> >> > > > >> > loader
> >> >> ?
> >> >> >> > > > >> > If we could load the system class by different loaders
> >> >> >> > > > >> > other
> >> >> than
> >> >> >> > the
> >> >> >> > > > >> > bootstrap class loader then there is a chance to make
> the
> >> >> harmony
> >> >> >> > > > >> > runtime
> >> >> >> > > > >> to
> >> >> >> > > > >> > be osgi-ed.
> >> >> >> > > > >> > I trying to work on this problem . Do you have any
> >> >> suggestions ?
> >> >> >> > > > >> >
> >> >> >> > > > >> >
> >> >> >> > > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >> >> >> > > > >> >
> >> >> >> > > > >> >> Tian,
> >> >> >> > > > >> >> System classes are all loaded with bootstrap
> >> >> >> > > > >> >> classloader.
> >> >> >> > > > >> >> It
> >> >> is
> >> >> >> > > > >> >> written in C++ and is located in
> >> >> >> > > > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
> >> >> >> > > > >> >>
> >> >> >> > > > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
> >> >> >> > > > >> >> > Hi all
> >> >> >> > > > >> >> > I have a question about the classloading in the
> drlvm.
> >> >> >> > > > >> >> >
> >> >> >> > > > >> >> > I know that there are kernel library inside the
> drlvm
> >> >> >> > > > >> >> > such
> >> >> as
> >> >> >> > > > >> >> > java.lang.classloader, which enclose the the
> >> >> systemclassloader.
> >> >> >> > And
> >> >> >> > > > >> this
> >> >> >> > > > >> >> > class is loaded and used in the process of creating
> VM
> >> >> >> > > > >> >> > .
> >> >> >> > > > >> >> > While the systemclassloader is a subtype of
> >> >> >> > > > >> >> > urlclassloader
> >> >> >> > which is
> >> >> >> > > > >> >> > in
> >> >> >> > > > >> >> the
> >> >> >> > > > >> >> > "luni" module.So does the JNI_CreateJavaVM
> >> >> >> > > > >> >> > also load the urlclassloader in the boot procedure
> of
> >> >> >> > > > >> >> > vm
> >> >> ?(I
> >> >> >> > failed
> >> >> >> > > > >> >> > to
> >> >> >> > > > >> >> > search related code in the source code of drlvm).
> >> >> >> > > > >> >> > If so , when ?Before or after the jni available ?
> >> >> >> > > > >> >> > Since I am trying to implement the osgi on harmony
> and
> >> >> >> > > > >> >> > the
> >> >> osgi
> >> >> >> > > > works
> >> >> >> > > > >> >> with
> >> >> >> > > > >> >> > bundles (modules) , I think I need to know the
> >> >> >> > > > >> >> > procedure
> >> >> of
> >> >> >> > booting
> >> >> >> > > > >> and
> >> >> >> > > > >> >> > loading of class from different modules at the start
> >> >> >> > > > >> >> > up
> >> >> time.
> >> >> >> > > > >> >> > Any clue about this ?Thanks
> >> >> >> > > > >> >> >
> >> >> >> > > > >> >> > plus,do we have the source code of java.exe ?Where?
> >> >> >
> >> >> >
> >> >> >
> >> >>
> >> >>
> >> >>
> >> >> --
> >> >> http://people.apache.org/~xli <http://people.apache.org/%7Exli>
> >> >>
> >> >
> >> >
> >> >
> >> > --
> >> > Regards
> >> > Michael Tian
> >> >
> >>
> >
> >
> >
>
Re: Question about the boot and classloading
Posted by Pavel Pervov <pm...@gmail.com>.
Sure. I've posted from mobile, and my multitap betrayed me. Thanks, Mark.
2009/5/20, Mark Hindess <ma...@googlemail.com>:
>
> In message <e0...@mail.gmail.com>,
> Pavel Pervov writes:
>>
>> Please, read this nice presentation [1] on osgi vs classic class loading.
>> [1]
>> http://www.martinliqert.com/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
>
> I assume you mean:
>
>
> http://www.martinlippert.org/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
>
> -Mark.
>
>> 2009/5/19, tian galaxy <ha...@gmail.com>:
>> > XiaoFeng , Mark
>> > Thanks for your help ,very valuable to me.
>> > I think I need to research more on this .Much more complex than I
>> > thought
>> > previously.
>> >
>> >
>> > Regard
>> > Tian
>> >
>> > 2009/5/19 Xiao-Feng Li <xi...@gmail.com>
>> >
>> >> On Tue, May 19, 2009 at 6:41 PM, Mark Hindess
>> >> <ma...@googlemail.com> wrote:
>> >> >
>> >> > In message
>> >> > <df...@mail.gmail.com>,
>> >> tian
>> >> > galaxy writes:
>> >> >>
>> >> >> Hindess .Thanks for the help ! I realized that this far more complex
>> >> than I
>> >> >> thought before .
>> >> >> So I think I need a deeper look into both osgi and harmony .
>> >> >> Here are several things I don't qiute understand and I noted them
>> >> below.May
>> >> >> be it's because I am not quite familiar with the low level ,
>> >> classloading
>> >> >> details .
>> >> >> thanks!
>> >> >>
>> >> >> 2009/5/19 Mark Hindess <ma...@googlemail.com>
>> >> >> >
>> >> >> > In message <
>> >> dff214c70905180610w407e3bd4h5baa319729c1fc55@mail.gmail.com>,
>> >> >> > tian galaxy writes:
>> >> >> > >
>> >> >> > > OK ,thanks .Seems the minimal class set has been defined by the
>> >> osgi.
>> >> >> >
>> >> >> > Not sure how this helps though. The OSGi Minimum Execution
>> >> Environment
>> >> >> > says what is theoretically the minimum required to run OSGi. What
>> >> >> > we
>> >> >> > need to concern ourselves with is the *practical* minimum and that
>> >> >> > really depends on our implementation details.
>> >> >> >
>> >> >> > I don't think that we should implement OSGi in the VM. Instead
>> >> >> > the
>> >> >> > existing bootstrap classloader should load the OSGi framework
>> >> >> > (with
>> >> >> > a unique classloader)
>> >> >>
>> >> >> If we load the osgi with the bootstrap class loader , why comes a
>> >> >> unique
>> >> >> class loader?
>> >> >
>> >> > It isn't necessary but I think it is useful to use a separate
>> >> > classloader for the OSGi framework so that we can isolate the classes
>> >> > use by the VM's OSGi framework and avoid polluting the namespace.
>> >> >
>> >> >> Do you mean the bootstrap class loader should delegate the loading
>> >> >> to
>> >> >> the 'unique class loader '?
>> >> >
>> >> > Yes.
>> >> >
>> >> >> > and the system classes (with a "temporary" classloader).
>> >> >>
>> >> >> Again ,the relation between temporary and bootstrap classloder? And
>> >> >> why temporary ?
>> >> >
>> >> > Temporary because until the OSGi framework is up you wont know which
>> >> > bundle the classes belong to and thus wont know which bundle
>> >> > classloader
>> >> > the classes should belong to. Alternatively, I suppose you could
>> >> > implement minimal support for reading OSGi headers from manifests
>> >> > in the VM so that you could assign classes to what would become a
>> >> > bundle
>> >> > classloader when the framework is up.
>> >> >
>> >> > -Mark.
>> >>
>> >>
>> >> This makes sense to me. The VM simply grabs in all the stuff "as
>> >> usual" including the OSGi framework, then sort them out according to
>> >> the bundles' definitions.
>> >>
>> >> It could be VM-neutral, because it is the VM's own business to take
>> >> care of its loaded classes. A callback interface OSGI_ready() can
>> >> inform the VM to tidy up the classes loaded for OSGi (or before it is
>> >> ready).
>> >>
>> >> Thanks,
>> >> xiaofeng
>> >>
>> >>
>> >> >> > Once the OSGi framework is configured the system classes need to
>> >> >> > be
>> >> >> > moved to the correct classloader for the OSGi bundle to which they
>> >> >> > belong.
>> >> >> >
>> >> >> > This means that during the initial starting-OSGi-framework phase
>> >> >> > the OSGi bundle import/exports will not be enforced but, other
>> >> >> > than
>> >> >> > implementing OSGi in the VM, I don't see how to avoid this.
>> >> >> >
>> >> >> > The multiplicity of bootstrap classloaders still needs to be
>> >> >> > hidden
>> >> >> > since the API demands that getClassLoader should return null for
>> >> >> > the
>> >> >> > bootstrap classloader(s).
>> >> >> >
>> >> >> > The biggest problem is probably how to implement this as
>> >> VM-independent
>> >> >> > API such that a VM wanting to implement OSGi had to provide only a
>> >> >> > minimal C/Java interface in order to gain OSGi support.
>> >> >> >
>> >> >> > Regards,
>> >> >> > Mark.
>> >> >> >
>> >> >> > > I will look more closely on this problems and let you know if
>> >> >> > > there
>> >> some
>> >> >> > > progresses made.
>> >> >> > > Thanks a lot !
>> >> >> >
>> >> >> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> >> >> > >
>> >> >> > > > I do not know osgi model in detail, but what minimal set of
>> >> classes is
>> >> >> > > > needed to start osgi model itself? Then we could delegate to
>> >> "system"
>> >> >> > > > bundle loader from bootstrap classloader.
>> >> >> > > >
>> >> >> > > > 2009/5/18, tian galaxy <ha...@gmail.com>:
>> >> >> > > > > Yes , implement osgi loading model in there is too complex.
>> >> >> > > > >
>> >> >> > > > > We know some modules are more important than others ,
>> >> >> > > > > performing
>> >> some
>> >> >> > > > > fundamental , basic functions .
>> >> >> > > > > Is it possible to only load these more" basic " modules with
>> >> >> > bootstrap
>> >> >> > > > class
>> >> >> > > > > loader and make the other modules work the osgi bundle?
>> >> >> > > > > Actually I don't quite understand why system classes could
>> >> >> > > > > only
>> >> be
>> >> >> > loaded
>> >> >> > > > by
>> >> >> > > > > bootstrap class loader?I noticed that there are some safety
>> >> concerns
>> >> >> > > > > ,is there any reasons other than that?
>> >> >> > > > > Thanks !
>> >> >> > > > >
>> >> >> > > > >
>> >> >> > > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> >> >> > > > >
>> >> >> > > > >> Short answer is "no". You'll have to implement osgi loading
>> >> model
>> >> >> > > > >> inside bootstrap classloader. Is it too complex?
>> >> >> > > > >>
>> >> >> > > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
>> >> >> > > > >> > Hi Pavel.
>> >> >> > > > >> >
>> >> >> > > > >> > Thanks.
>> >> >> > > > >> > Yes ,that's right .My question is whether there is a way
>> >> >> > > > >> > to
>> >> load
>> >> >> > the
>> >> >> > > > >> system
>> >> >> > > > >> > class by class loader other than the bootstrap class
>> >> >> > > > >> > loader
>> >> ?
>> >> >> > > > >> > If we could load the system class by different loaders
>> >> >> > > > >> > other
>> >> than
>> >> >> > the
>> >> >> > > > >> > bootstrap class loader then there is a chance to make the
>> >> harmony
>> >> >> > > > >> > runtime
>> >> >> > > > >> to
>> >> >> > > > >> > be osgi-ed.
>> >> >> > > > >> > I trying to work on this problem . Do you have any
>> >> suggestions ?
>> >> >> > > > >> >
>> >> >> > > > >> >
>> >> >> > > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> >> >> > > > >> >
>> >> >> > > > >> >> Tian,
>> >> >> > > > >> >> System classes are all loaded with bootstrap
>> >> >> > > > >> >> classloader.
>> >> >> > > > >> >> It
>> >> is
>> >> >> > > > >> >> written in C++ and is located in
>> >> >> > > > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
>> >> >> > > > >> >>
>> >> >> > > > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
>> >> >> > > > >> >> > Hi all
>> >> >> > > > >> >> > I have a question about the classloading in the drlvm.
>> >> >> > > > >> >> >
>> >> >> > > > >> >> > I know that there are kernel library inside the drlvm
>> >> >> > > > >> >> > such
>> >> as
>> >> >> > > > >> >> > java.lang.classloader, which enclose the the
>> >> systemclassloader.
>> >> >> > And
>> >> >> > > > >> this
>> >> >> > > > >> >> > class is loaded and used in the process of creating VM
>> >> >> > > > >> >> > .
>> >> >> > > > >> >> > While the systemclassloader is a subtype of
>> >> >> > > > >> >> > urlclassloader
>> >> >> > which is
>> >> >> > > > >> >> > in
>> >> >> > > > >> >> the
>> >> >> > > > >> >> > "luni" module.So does the JNI_CreateJavaVM
>> >> >> > > > >> >> > also load the urlclassloader in the boot procedure of
>> >> >> > > > >> >> > vm
>> >> ?(I
>> >> >> > failed
>> >> >> > > > >> >> > to
>> >> >> > > > >> >> > search related code in the source code of drlvm).
>> >> >> > > > >> >> > If so , when ?Before or after the jni available ?
>> >> >> > > > >> >> > Since I am trying to implement the osgi on harmony and
>> >> >> > > > >> >> > the
>> >> osgi
>> >> >> > > > works
>> >> >> > > > >> >> with
>> >> >> > > > >> >> > bundles (modules) , I think I need to know the
>> >> >> > > > >> >> > procedure
>> >> of
>> >> >> > booting
>> >> >> > > > >> and
>> >> >> > > > >> >> > loading of class from different modules at the start
>> >> >> > > > >> >> > up
>> >> time.
>> >> >> > > > >> >> > Any clue about this ?Thanks
>> >> >> > > > >> >> >
>> >> >> > > > >> >> > plus,do we have the source code of java.exe ?Where?
>> >> >
>> >> >
>> >> >
>> >>
>> >>
>> >>
>> >> --
>> >> http://people.apache.org/~xli
>> >>
>> >
>> >
>> >
>> > --
>> > Regards
>> > Michael Tian
>> >
>>
>
>
>
Re: Question about the boot and classloading
Posted by Mark Hindess <ma...@googlemail.com>.
In message <e0...@mail.gmail.com>,
Pavel Pervov writes:
>
> Please, read this nice presentation [1] on osgi vs classic class loading.
> [1] http://www.martinliqert.com/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
I assume you mean:
http://www.martinlippert.org/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
-Mark.
> 2009/5/19, tian galaxy <ha...@gmail.com>:
> > XiaoFeng , Mark
> > Thanks for your help ,very valuable to me.
> > I think I need to research more on this .Much more complex than I thought
> > previously.
> >
> >
> > Regard
> > Tian
> >
> > 2009/5/19 Xiao-Feng Li <xi...@gmail.com>
> >
> >> On Tue, May 19, 2009 at 6:41 PM, Mark Hindess
> >> <ma...@googlemail.com> wrote:
> >> >
> >> > In message
> >> > <df...@mail.gmail.com>,
> >> tian
> >> > galaxy writes:
> >> >>
> >> >> Hindess .Thanks for the help ! I realized that this far more complex
> >> than I
> >> >> thought before .
> >> >> So I think I need a deeper look into both osgi and harmony .
> >> >> Here are several things I don't qiute understand and I noted them
> >> below.May
> >> >> be it's because I am not quite familiar with the low level ,
> >> classloading
> >> >> details .
> >> >> thanks!
> >> >>
> >> >> 2009/5/19 Mark Hindess <ma...@googlemail.com>
> >> >> >
> >> >> > In message <
> >> dff214c70905180610w407e3bd4h5baa319729c1fc55@mail.gmail.com>,
> >> >> > tian galaxy writes:
> >> >> > >
> >> >> > > OK ,thanks .Seems the minimal class set has been defined by the
> >> osgi.
> >> >> >
> >> >> > Not sure how this helps though. The OSGi Minimum Execution
> >> Environment
> >> >> > says what is theoretically the minimum required to run OSGi. What we
> >> >> > need to concern ourselves with is the *practical* minimum and that
> >> >> > really depends on our implementation details.
> >> >> >
> >> >> > I don't think that we should implement OSGi in the VM. Instead the
> >> >> > existing bootstrap classloader should load the OSGi framework (with
> >> >> > a unique classloader)
> >> >>
> >> >> If we load the osgi with the bootstrap class loader , why comes a
> >> >> unique
> >> >> class loader?
> >> >
> >> > It isn't necessary but I think it is useful to use a separate
> >> > classloader for the OSGi framework so that we can isolate the classes
> >> > use by the VM's OSGi framework and avoid polluting the namespace.
> >> >
> >> >> Do you mean the bootstrap class loader should delegate the loading to
> >> >> the 'unique class loader '?
> >> >
> >> > Yes.
> >> >
> >> >> > and the system classes (with a "temporary" classloader).
> >> >>
> >> >> Again ,the relation between temporary and bootstrap classloder? And
> >> >> why temporary ?
> >> >
> >> > Temporary because until the OSGi framework is up you wont know which
> >> > bundle the classes belong to and thus wont know which bundle classloader
> >> > the classes should belong to. Alternatively, I suppose you could
> >> > implement minimal support for reading OSGi headers from manifests
> >> > in the VM so that you could assign classes to what would become a bundle
> >> > classloader when the framework is up.
> >> >
> >> > -Mark.
> >>
> >>
> >> This makes sense to me. The VM simply grabs in all the stuff "as
> >> usual" including the OSGi framework, then sort them out according to
> >> the bundles' definitions.
> >>
> >> It could be VM-neutral, because it is the VM's own business to take
> >> care of its loaded classes. A callback interface OSGI_ready() can
> >> inform the VM to tidy up the classes loaded for OSGi (or before it is
> >> ready).
> >>
> >> Thanks,
> >> xiaofeng
> >>
> >>
> >> >> > Once the OSGi framework is configured the system classes need to be
> >> >> > moved to the correct classloader for the OSGi bundle to which they
> >> >> > belong.
> >> >> >
> >> >> > This means that during the initial starting-OSGi-framework phase
> >> >> > the OSGi bundle import/exports will not be enforced but, other than
> >> >> > implementing OSGi in the VM, I don't see how to avoid this.
> >> >> >
> >> >> > The multiplicity of bootstrap classloaders still needs to be hidden
> >> >> > since the API demands that getClassLoader should return null for the
> >> >> > bootstrap classloader(s).
> >> >> >
> >> >> > The biggest problem is probably how to implement this as
> >> VM-independent
> >> >> > API such that a VM wanting to implement OSGi had to provide only a
> >> >> > minimal C/Java interface in order to gain OSGi support.
> >> >> >
> >> >> > Regards,
> >> >> > Mark.
> >> >> >
> >> >> > > I will look more closely on this problems and let you know if there
> >> some
> >> >> > > progresses made.
> >> >> > > Thanks a lot !
> >> >> >
> >> >> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >> >> > >
> >> >> > > > I do not know osgi model in detail, but what minimal set of
> >> classes is
> >> >> > > > needed to start osgi model itself? Then we could delegate to
> >> "system"
> >> >> > > > bundle loader from bootstrap classloader.
> >> >> > > >
> >> >> > > > 2009/5/18, tian galaxy <ha...@gmail.com>:
> >> >> > > > > Yes , implement osgi loading model in there is too complex.
> >> >> > > > >
> >> >> > > > > We know some modules are more important than others ,
> >> >> > > > > performing
> >> some
> >> >> > > > > fundamental , basic functions .
> >> >> > > > > Is it possible to only load these more" basic " modules with
> >> >> > bootstrap
> >> >> > > > class
> >> >> > > > > loader and make the other modules work the osgi bundle?
> >> >> > > > > Actually I don't quite understand why system classes could only
> >> be
> >> >> > loaded
> >> >> > > > by
> >> >> > > > > bootstrap class loader?I noticed that there are some safety
> >> concerns
> >> >> > > > > ,is there any reasons other than that?
> >> >> > > > > Thanks !
> >> >> > > > >
> >> >> > > > >
> >> >> > > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >> >> > > > >
> >> >> > > > >> Short answer is "no". You'll have to implement osgi loading
> >> model
> >> >> > > > >> inside bootstrap classloader. Is it too complex?
> >> >> > > > >>
> >> >> > > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
> >> >> > > > >> > Hi Pavel.
> >> >> > > > >> >
> >> >> > > > >> > Thanks.
> >> >> > > > >> > Yes ,that's right .My question is whether there is a way to
> >> load
> >> >> > the
> >> >> > > > >> system
> >> >> > > > >> > class by class loader other than the bootstrap class loader
> >> ?
> >> >> > > > >> > If we could load the system class by different loaders other
> >> than
> >> >> > the
> >> >> > > > >> > bootstrap class loader then there is a chance to make the
> >> harmony
> >> >> > > > >> > runtime
> >> >> > > > >> to
> >> >> > > > >> > be osgi-ed.
> >> >> > > > >> > I trying to work on this problem . Do you have any
> >> suggestions ?
> >> >> > > > >> >
> >> >> > > > >> >
> >> >> > > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >> >> > > > >> >
> >> >> > > > >> >> Tian,
> >> >> > > > >> >> System classes are all loaded with bootstrap classloader.
> >> >> > > > >> >> It
> >> is
> >> >> > > > >> >> written in C++ and is located in
> >> >> > > > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
> >> >> > > > >> >>
> >> >> > > > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
> >> >> > > > >> >> > Hi all
> >> >> > > > >> >> > I have a question about the classloading in the drlvm.
> >> >> > > > >> >> >
> >> >> > > > >> >> > I know that there are kernel library inside the drlvm
> >> >> > > > >> >> > such
> >> as
> >> >> > > > >> >> > java.lang.classloader, which enclose the the
> >> systemclassloader.
> >> >> > And
> >> >> > > > >> this
> >> >> > > > >> >> > class is loaded and used in the process of creating VM .
> >> >> > > > >> >> > While the systemclassloader is a subtype of
> >> >> > > > >> >> > urlclassloader
> >> >> > which is
> >> >> > > > >> >> > in
> >> >> > > > >> >> the
> >> >> > > > >> >> > "luni" module.So does the JNI_CreateJavaVM
> >> >> > > > >> >> > also load the urlclassloader in the boot procedure of vm
> >> ?(I
> >> >> > failed
> >> >> > > > >> >> > to
> >> >> > > > >> >> > search related code in the source code of drlvm).
> >> >> > > > >> >> > If so , when ?Before or after the jni available ?
> >> >> > > > >> >> > Since I am trying to implement the osgi on harmony and
> >> >> > > > >> >> > the
> >> osgi
> >> >> > > > works
> >> >> > > > >> >> with
> >> >> > > > >> >> > bundles (modules) , I think I need to know the procedure
> >> of
> >> >> > booting
> >> >> > > > >> and
> >> >> > > > >> >> > loading of class from different modules at the start up
> >> time.
> >> >> > > > >> >> > Any clue about this ?Thanks
> >> >> > > > >> >> >
> >> >> > > > >> >> > plus,do we have the source code of java.exe ?Where?
> >> >
> >> >
> >> >
> >>
> >>
> >>
> >> --
> >> http://people.apache.org/~xli
> >>
> >
> >
> >
> > --
> > Regards
> > Michael Tian
> >
>
Re: Question about the boot and classloading
Posted by Pavel Pervov <pm...@gmail.com>.
Please, read this nice presentation [1] on osgi vs classic class loading.
[1] http://www.martinliqert.com/events/WJAX2008-ClassloadingTypeVisibilityOSGi.pdf
2009/5/19, tian galaxy <ha...@gmail.com>:
> XiaoFeng , Mark
> Thanks for your help ,very valuable to me.
> I think I need to research more on this .Much more complex than I thought
> previously.
>
>
> Regard
> Tian
>
> 2009/5/19 Xiao-Feng Li <xi...@gmail.com>
>
>> On Tue, May 19, 2009 at 6:41 PM, Mark Hindess
>> <ma...@googlemail.com> wrote:
>> >
>> > In message
>> > <df...@mail.gmail.com>,
>> tian
>> > galaxy writes:
>> >>
>> >> Hindess .Thanks for the help ! I realized that this far more complex
>> than I
>> >> thought before .
>> >> So I think I need a deeper look into both osgi and harmony .
>> >> Here are several things I don't qiute understand and I noted them
>> below.May
>> >> be it's because I am not quite familiar with the low level ,
>> classloading
>> >> details .
>> >> thanks!
>> >>
>> >> 2009/5/19 Mark Hindess <ma...@googlemail.com>
>> >> >
>> >> > In message <
>> dff214c70905180610w407e3bd4h5baa319729c1fc55@mail.gmail.com>,
>> >> > tian galaxy writes:
>> >> > >
>> >> > > OK ,thanks .Seems the minimal class set has been defined by the
>> osgi.
>> >> >
>> >> > Not sure how this helps though. The OSGi Minimum Execution
>> Environment
>> >> > says what is theoretically the minimum required to run OSGi. What we
>> >> > need to concern ourselves with is the *practical* minimum and that
>> >> > really depends on our implementation details.
>> >> >
>> >> > I don't think that we should implement OSGi in the VM. Instead the
>> >> > existing bootstrap classloader should load the OSGi framework (with
>> >> > a unique classloader)
>> >>
>> >> If we load the osgi with the bootstrap class loader , why comes a
>> >> unique
>> >> class loader?
>> >
>> > It isn't necessary but I think it is useful to use a separate
>> > classloader for the OSGi framework so that we can isolate the classes
>> > use by the VM's OSGi framework and avoid polluting the namespace.
>> >
>> >> Do you mean the bootstrap class loader should delegate the loading to
>> >> the 'unique class loader '?
>> >
>> > Yes.
>> >
>> >> > and the system classes (with a "temporary" classloader).
>> >>
>> >> Again ,the relation between temporary and bootstrap classloder? And
>> >> why temporary ?
>> >
>> > Temporary because until the OSGi framework is up you wont know which
>> > bundle the classes belong to and thus wont know which bundle classloader
>> > the classes should belong to. Alternatively, I suppose you could
>> > implement minimal support for reading OSGi headers from manifests
>> > in the VM so that you could assign classes to what would become a bundle
>> > classloader when the framework is up.
>> >
>> > -Mark.
>>
>>
>> This makes sense to me. The VM simply grabs in all the stuff "as
>> usual" including the OSGi framework, then sort them out according to
>> the bundles' definitions.
>>
>> It could be VM-neutral, because it is the VM's own business to take
>> care of its loaded classes. A callback interface OSGI_ready() can
>> inform the VM to tidy up the classes loaded for OSGi (or before it is
>> ready).
>>
>> Thanks,
>> xiaofeng
>>
>>
>> >> > Once the OSGi framework is configured the system classes need to be
>> >> > moved to the correct classloader for the OSGi bundle to which they
>> >> > belong.
>> >> >
>> >> > This means that during the initial starting-OSGi-framework phase
>> >> > the OSGi bundle import/exports will not be enforced but, other than
>> >> > implementing OSGi in the VM, I don't see how to avoid this.
>> >> >
>> >> > The multiplicity of bootstrap classloaders still needs to be hidden
>> >> > since the API demands that getClassLoader should return null for the
>> >> > bootstrap classloader(s).
>> >> >
>> >> > The biggest problem is probably how to implement this as
>> VM-independent
>> >> > API such that a VM wanting to implement OSGi had to provide only a
>> >> > minimal C/Java interface in order to gain OSGi support.
>> >> >
>> >> > Regards,
>> >> > Mark.
>> >> >
>> >> > > I will look more closely on this problems and let you know if there
>> some
>> >> > > progresses made.
>> >> > > Thanks a lot !
>> >> >
>> >> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> >> > >
>> >> > > > I do not know osgi model in detail, but what minimal set of
>> classes is
>> >> > > > needed to start osgi model itself? Then we could delegate to
>> "system"
>> >> > > > bundle loader from bootstrap classloader.
>> >> > > >
>> >> > > > 2009/5/18, tian galaxy <ha...@gmail.com>:
>> >> > > > > Yes , implement osgi loading model in there is too complex.
>> >> > > > >
>> >> > > > > We know some modules are more important than others ,
>> >> > > > > performing
>> some
>> >> > > > > fundamental , basic functions .
>> >> > > > > Is it possible to only load these more" basic " modules with
>> >> > bootstrap
>> >> > > > class
>> >> > > > > loader and make the other modules work the osgi bundle?
>> >> > > > > Actually I don't quite understand why system classes could only
>> be
>> >> > loaded
>> >> > > > by
>> >> > > > > bootstrap class loader?I noticed that there are some safety
>> concerns
>> >> > > > > ,is there any reasons other than that?
>> >> > > > > Thanks !
>> >> > > > >
>> >> > > > >
>> >> > > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> >> > > > >
>> >> > > > >> Short answer is "no". You'll have to implement osgi loading
>> model
>> >> > > > >> inside bootstrap classloader. Is it too complex?
>> >> > > > >>
>> >> > > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
>> >> > > > >> > Hi Pavel.
>> >> > > > >> >
>> >> > > > >> > Thanks.
>> >> > > > >> > Yes ,that's right .My question is whether there is a way to
>> load
>> >> > the
>> >> > > > >> system
>> >> > > > >> > class by class loader other than the bootstrap class loader
>> ?
>> >> > > > >> > If we could load the system class by different loaders other
>> than
>> >> > the
>> >> > > > >> > bootstrap class loader then there is a chance to make the
>> harmony
>> >> > > > >> > runtime
>> >> > > > >> to
>> >> > > > >> > be osgi-ed.
>> >> > > > >> > I trying to work on this problem . Do you have any
>> suggestions ?
>> >> > > > >> >
>> >> > > > >> >
>> >> > > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> >> > > > >> >
>> >> > > > >> >> Tian,
>> >> > > > >> >> System classes are all loaded with bootstrap classloader.
>> >> > > > >> >> It
>> is
>> >> > > > >> >> written in C++ and is located in
>> >> > > > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
>> >> > > > >> >>
>> >> > > > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
>> >> > > > >> >> > Hi all
>> >> > > > >> >> > I have a question about the classloading in the drlvm.
>> >> > > > >> >> >
>> >> > > > >> >> > I know that there are kernel library inside the drlvm
>> >> > > > >> >> > such
>> as
>> >> > > > >> >> > java.lang.classloader, which enclose the the
>> systemclassloader.
>> >> > And
>> >> > > > >> this
>> >> > > > >> >> > class is loaded and used in the process of creating VM .
>> >> > > > >> >> > While the systemclassloader is a subtype of
>> >> > > > >> >> > urlclassloader
>> >> > which is
>> >> > > > >> >> > in
>> >> > > > >> >> the
>> >> > > > >> >> > "luni" module.So does the JNI_CreateJavaVM
>> >> > > > >> >> > also load the urlclassloader in the boot procedure of vm
>> ?(I
>> >> > failed
>> >> > > > >> >> > to
>> >> > > > >> >> > search related code in the source code of drlvm).
>> >> > > > >> >> > If so , when ?Before or after the jni available ?
>> >> > > > >> >> > Since I am trying to implement the osgi on harmony and
>> >> > > > >> >> > the
>> osgi
>> >> > > > works
>> >> > > > >> >> with
>> >> > > > >> >> > bundles (modules) , I think I need to know the procedure
>> of
>> >> > booting
>> >> > > > >> and
>> >> > > > >> >> > loading of class from different modules at the start up
>> time.
>> >> > > > >> >> > Any clue about this ?Thanks
>> >> > > > >> >> >
>> >> > > > >> >> > plus,do we have the source code of java.exe ?Where?
>> >
>> >
>> >
>>
>>
>>
>> --
>> http://people.apache.org/~xli
>>
>
>
>
> --
> Regards
> Michael Tian
>
Re: Question about the boot and classloading
Posted by tian galaxy <ha...@gmail.com>.
XiaoFeng , Mark
Thanks for your help ,very valuable to me.
I think I need to research more on this .Much more complex than I thought
previously.
Regard
Tian
2009/5/19 Xiao-Feng Li <xi...@gmail.com>
> On Tue, May 19, 2009 at 6:41 PM, Mark Hindess
> <ma...@googlemail.com> wrote:
> >
> > In message <df...@mail.gmail.com>,
> tian
> > galaxy writes:
> >>
> >> Hindess .Thanks for the help ! I realized that this far more complex
> than I
> >> thought before .
> >> So I think I need a deeper look into both osgi and harmony .
> >> Here are several things I don't qiute understand and I noted them
> below.May
> >> be it's because I am not quite familiar with the low level ,
> classloading
> >> details .
> >> thanks!
> >>
> >> 2009/5/19 Mark Hindess <ma...@googlemail.com>
> >> >
> >> > In message <
> dff214c70905180610w407e3bd4h5baa319729c1fc55@mail.gmail.com>,
> >> > tian galaxy writes:
> >> > >
> >> > > OK ,thanks .Seems the minimal class set has been defined by the
> osgi.
> >> >
> >> > Not sure how this helps though. The OSGi Minimum Execution
> Environment
> >> > says what is theoretically the minimum required to run OSGi. What we
> >> > need to concern ourselves with is the *practical* minimum and that
> >> > really depends on our implementation details.
> >> >
> >> > I don't think that we should implement OSGi in the VM. Instead the
> >> > existing bootstrap classloader should load the OSGi framework (with
> >> > a unique classloader)
> >>
> >> If we load the osgi with the bootstrap class loader , why comes a unique
> >> class loader?
> >
> > It isn't necessary but I think it is useful to use a separate
> > classloader for the OSGi framework so that we can isolate the classes
> > use by the VM's OSGi framework and avoid polluting the namespace.
> >
> >> Do you mean the bootstrap class loader should delegate the loading to
> >> the 'unique class loader '?
> >
> > Yes.
> >
> >> > and the system classes (with a "temporary" classloader).
> >>
> >> Again ,the relation between temporary and bootstrap classloder? And
> >> why temporary ?
> >
> > Temporary because until the OSGi framework is up you wont know which
> > bundle the classes belong to and thus wont know which bundle classloader
> > the classes should belong to. Alternatively, I suppose you could
> > implement minimal support for reading OSGi headers from manifests
> > in the VM so that you could assign classes to what would become a bundle
> > classloader when the framework is up.
> >
> > -Mark.
>
>
> This makes sense to me. The VM simply grabs in all the stuff "as
> usual" including the OSGi framework, then sort them out according to
> the bundles' definitions.
>
> It could be VM-neutral, because it is the VM's own business to take
> care of its loaded classes. A callback interface OSGI_ready() can
> inform the VM to tidy up the classes loaded for OSGi (or before it is
> ready).
>
> Thanks,
> xiaofeng
>
>
> >> > Once the OSGi framework is configured the system classes need to be
> >> > moved to the correct classloader for the OSGi bundle to which they
> >> > belong.
> >> >
> >> > This means that during the initial starting-OSGi-framework phase
> >> > the OSGi bundle import/exports will not be enforced but, other than
> >> > implementing OSGi in the VM, I don't see how to avoid this.
> >> >
> >> > The multiplicity of bootstrap classloaders still needs to be hidden
> >> > since the API demands that getClassLoader should return null for the
> >> > bootstrap classloader(s).
> >> >
> >> > The biggest problem is probably how to implement this as
> VM-independent
> >> > API such that a VM wanting to implement OSGi had to provide only a
> >> > minimal C/Java interface in order to gain OSGi support.
> >> >
> >> > Regards,
> >> > Mark.
> >> >
> >> > > I will look more closely on this problems and let you know if there
> some
> >> > > progresses made.
> >> > > Thanks a lot !
> >> >
> >> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >> > >
> >> > > > I do not know osgi model in detail, but what minimal set of
> classes is
> >> > > > needed to start osgi model itself? Then we could delegate to
> "system"
> >> > > > bundle loader from bootstrap classloader.
> >> > > >
> >> > > > 2009/5/18, tian galaxy <ha...@gmail.com>:
> >> > > > > Yes , implement osgi loading model in there is too complex.
> >> > > > >
> >> > > > > We know some modules are more important than others , performing
> some
> >> > > > > fundamental , basic functions .
> >> > > > > Is it possible to only load these more" basic " modules with
> >> > bootstrap
> >> > > > class
> >> > > > > loader and make the other modules work the osgi bundle?
> >> > > > > Actually I don't quite understand why system classes could only
> be
> >> > loaded
> >> > > > by
> >> > > > > bootstrap class loader?I noticed that there are some safety
> concerns
> >> > > > > ,is there any reasons other than that?
> >> > > > > Thanks !
> >> > > > >
> >> > > > >
> >> > > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >> > > > >
> >> > > > >> Short answer is "no". You'll have to implement osgi loading
> model
> >> > > > >> inside bootstrap classloader. Is it too complex?
> >> > > > >>
> >> > > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
> >> > > > >> > Hi Pavel.
> >> > > > >> >
> >> > > > >> > Thanks.
> >> > > > >> > Yes ,that's right .My question is whether there is a way to
> load
> >> > the
> >> > > > >> system
> >> > > > >> > class by class loader other than the bootstrap class loader
> ?
> >> > > > >> > If we could load the system class by different loaders other
> than
> >> > the
> >> > > > >> > bootstrap class loader then there is a chance to make the
> harmony
> >> > > > >> > runtime
> >> > > > >> to
> >> > > > >> > be osgi-ed.
> >> > > > >> > I trying to work on this problem . Do you have any
> suggestions ?
> >> > > > >> >
> >> > > > >> >
> >> > > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >> > > > >> >
> >> > > > >> >> Tian,
> >> > > > >> >> System classes are all loaded with bootstrap classloader. It
> is
> >> > > > >> >> written in C++ and is located in
> >> > > > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
> >> > > > >> >>
> >> > > > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
> >> > > > >> >> > Hi all
> >> > > > >> >> > I have a question about the classloading in the drlvm.
> >> > > > >> >> >
> >> > > > >> >> > I know that there are kernel library inside the drlvm such
> as
> >> > > > >> >> > java.lang.classloader, which enclose the the
> systemclassloader.
> >> > And
> >> > > > >> this
> >> > > > >> >> > class is loaded and used in the process of creating VM .
> >> > > > >> >> > While the systemclassloader is a subtype of urlclassloader
> >> > which is
> >> > > > >> >> > in
> >> > > > >> >> the
> >> > > > >> >> > "luni" module.So does the JNI_CreateJavaVM
> >> > > > >> >> > also load the urlclassloader in the boot procedure of vm
> ?(I
> >> > failed
> >> > > > >> >> > to
> >> > > > >> >> > search related code in the source code of drlvm).
> >> > > > >> >> > If so , when ?Before or after the jni available ?
> >> > > > >> >> > Since I am trying to implement the osgi on harmony and the
> osgi
> >> > > > works
> >> > > > >> >> with
> >> > > > >> >> > bundles (modules) , I think I need to know the procedure
> of
> >> > booting
> >> > > > >> and
> >> > > > >> >> > loading of class from different modules at the start up
> time.
> >> > > > >> >> > Any clue about this ?Thanks
> >> > > > >> >> >
> >> > > > >> >> > plus,do we have the source code of java.exe ?Where?
> >
> >
> >
>
>
>
> --
> http://people.apache.org/~xli
>
--
Regards
Michael Tian
Re: Question about the boot and classloading
Posted by Xiao-Feng Li <xi...@gmail.com>.
On Tue, May 19, 2009 at 6:41 PM, Mark Hindess
<ma...@googlemail.com> wrote:
>
> In message <df...@mail.gmail.com>, tian
> galaxy writes:
>>
>> Hindess .Thanks for the help ! I realized that this far more complex than I
>> thought before .
>> So I think I need a deeper look into both osgi and harmony .
>> Here are several things I don't qiute understand and I noted them below.May
>> be it's because I am not quite familiar with the low level , classloading
>> details .
>> thanks!
>>
>> 2009/5/19 Mark Hindess <ma...@googlemail.com>
>> >
>> > In message <df...@mail.gmail.com>,
>> > tian galaxy writes:
>> > >
>> > > OK ,thanks .Seems the minimal class set has been defined by the osgi.
>> >
>> > Not sure how this helps though. The OSGi Minimum Execution Environment
>> > says what is theoretically the minimum required to run OSGi. What we
>> > need to concern ourselves with is the *practical* minimum and that
>> > really depends on our implementation details.
>> >
>> > I don't think that we should implement OSGi in the VM. Instead the
>> > existing bootstrap classloader should load the OSGi framework (with
>> > a unique classloader)
>>
>> If we load the osgi with the bootstrap class loader , why comes a unique
>> class loader?
>
> It isn't necessary but I think it is useful to use a separate
> classloader for the OSGi framework so that we can isolate the classes
> use by the VM's OSGi framework and avoid polluting the namespace.
>
>> Do you mean the bootstrap class loader should delegate the loading to
>> the 'unique class loader '?
>
> Yes.
>
>> > and the system classes (with a "temporary" classloader).
>>
>> Again ,the relation between temporary and bootstrap classloder? And
>> why temporary ?
>
> Temporary because until the OSGi framework is up you wont know which
> bundle the classes belong to and thus wont know which bundle classloader
> the classes should belong to. Alternatively, I suppose you could
> implement minimal support for reading OSGi headers from manifests
> in the VM so that you could assign classes to what would become a bundle
> classloader when the framework is up.
>
> -Mark.
This makes sense to me. The VM simply grabs in all the stuff "as
usual" including the OSGi framework, then sort them out according to
the bundles' definitions.
It could be VM-neutral, because it is the VM's own business to take
care of its loaded classes. A callback interface OSGI_ready() can
inform the VM to tidy up the classes loaded for OSGi (or before it is
ready).
Thanks,
xiaofeng
>> > Once the OSGi framework is configured the system classes need to be
>> > moved to the correct classloader for the OSGi bundle to which they
>> > belong.
>> >
>> > This means that during the initial starting-OSGi-framework phase
>> > the OSGi bundle import/exports will not be enforced but, other than
>> > implementing OSGi in the VM, I don't see how to avoid this.
>> >
>> > The multiplicity of bootstrap classloaders still needs to be hidden
>> > since the API demands that getClassLoader should return null for the
>> > bootstrap classloader(s).
>> >
>> > The biggest problem is probably how to implement this as VM-independent
>> > API such that a VM wanting to implement OSGi had to provide only a
>> > minimal C/Java interface in order to gain OSGi support.
>> >
>> > Regards,
>> > Mark.
>> >
>> > > I will look more closely on this problems and let you know if there some
>> > > progresses made.
>> > > Thanks a lot !
>> >
>> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> > >
>> > > > I do not know osgi model in detail, but what minimal set of classes is
>> > > > needed to start osgi model itself? Then we could delegate to "system"
>> > > > bundle loader from bootstrap classloader.
>> > > >
>> > > > 2009/5/18, tian galaxy <ha...@gmail.com>:
>> > > > > Yes , implement osgi loading model in there is too complex.
>> > > > >
>> > > > > We know some modules are more important than others , performing some
>> > > > > fundamental , basic functions .
>> > > > > Is it possible to only load these more" basic " modules with
>> > bootstrap
>> > > > class
>> > > > > loader and make the other modules work the osgi bundle?
>> > > > > Actually I don't quite understand why system classes could only be
>> > loaded
>> > > > by
>> > > > > bootstrap class loader?I noticed that there are some safety concerns
>> > > > > ,is there any reasons other than that?
>> > > > > Thanks !
>> > > > >
>> > > > >
>> > > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> > > > >
>> > > > >> Short answer is "no". You'll have to implement osgi loading model
>> > > > >> inside bootstrap classloader. Is it too complex?
>> > > > >>
>> > > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
>> > > > >> > Hi Pavel.
>> > > > >> >
>> > > > >> > Thanks.
>> > > > >> > Yes ,that's right .My question is whether there is a way to load
>> > the
>> > > > >> system
>> > > > >> > class by class loader other than the bootstrap class loader ?
>> > > > >> > If we could load the system class by different loaders other than
>> > the
>> > > > >> > bootstrap class loader then there is a chance to make the harmony
>> > > > >> > runtime
>> > > > >> to
>> > > > >> > be osgi-ed.
>> > > > >> > I trying to work on this problem . Do you have any suggestions ?
>> > > > >> >
>> > > > >> >
>> > > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
>> > > > >> >
>> > > > >> >> Tian,
>> > > > >> >> System classes are all loaded with bootstrap classloader. It is
>> > > > >> >> written in C++ and is located in
>> > > > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
>> > > > >> >>
>> > > > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
>> > > > >> >> > Hi all
>> > > > >> >> > I have a question about the classloading in the drlvm.
>> > > > >> >> >
>> > > > >> >> > I know that there are kernel library inside the drlvm such as
>> > > > >> >> > java.lang.classloader, which enclose the the systemclassloader.
>> > And
>> > > > >> this
>> > > > >> >> > class is loaded and used in the process of creating VM .
>> > > > >> >> > While the systemclassloader is a subtype of urlclassloader
>> > which is
>> > > > >> >> > in
>> > > > >> >> the
>> > > > >> >> > "luni" module.So does the JNI_CreateJavaVM
>> > > > >> >> > also load the urlclassloader in the boot procedure of vm ?(I
>> > failed
>> > > > >> >> > to
>> > > > >> >> > search related code in the source code of drlvm).
>> > > > >> >> > If so , when ?Before or after the jni available ?
>> > > > >> >> > Since I am trying to implement the osgi on harmony and the osgi
>> > > > works
>> > > > >> >> with
>> > > > >> >> > bundles (modules) , I think I need to know the procedure of
>> > booting
>> > > > >> and
>> > > > >> >> > loading of class from different modules at the start up time.
>> > > > >> >> > Any clue about this ?Thanks
>> > > > >> >> >
>> > > > >> >> > plus,do we have the source code of java.exe ?Where?
>
>
>
--
http://people.apache.org/~xli
Re: Question about the boot and classloading
Posted by Mark Hindess <ma...@googlemail.com>.
In message <df...@mail.gmail.com>, tian
galaxy writes:
>
> Hindess .Thanks for the help ! I realized that this far more complex than I
> thought before .
> So I think I need a deeper look into both osgi and harmony .
> Here are several things I don't qiute understand and I noted them below.May
> be it's because I am not quite familiar with the low level , classloading
> details .
> thanks!
>
> 2009/5/19 Mark Hindess <ma...@googlemail.com>
> >
> > In message <df...@mail.gmail.com>,
> > tian galaxy writes:
> > >
> > > OK ,thanks .Seems the minimal class set has been defined by the osgi.
> >
> > Not sure how this helps though. The OSGi Minimum Execution Environment
> > says what is theoretically the minimum required to run OSGi. What we
> > need to concern ourselves with is the *practical* minimum and that
> > really depends on our implementation details.
> >
> > I don't think that we should implement OSGi in the VM. Instead the
> > existing bootstrap classloader should load the OSGi framework (with
> > a unique classloader)
>
> If we load the osgi with the bootstrap class loader , why comes a unique
> class loader?
It isn't necessary but I think it is useful to use a separate
classloader for the OSGi framework so that we can isolate the classes
use by the VM's OSGi framework and avoid polluting the namespace.
> Do you mean the bootstrap class loader should delegate the loading to
> the 'unique class loader '?
Yes.
> > and the system classes (with a "temporary" classloader).
>
> Again ,the relation between temporary and bootstrap classloder? And
> why temporary ?
Temporary because until the OSGi framework is up you wont know which
bundle the classes belong to and thus wont know which bundle classloader
the classes should belong to. Alternatively, I suppose you could
implement minimal support for reading OSGi headers from manifests
in the VM so that you could assign classes to what would become a bundle
classloader when the framework is up.
-Mark.
> > Once the OSGi framework is configured the system classes need to be
> > moved to the correct classloader for the OSGi bundle to which they
> > belong.
> >
> > This means that during the initial starting-OSGi-framework phase
> > the OSGi bundle import/exports will not be enforced but, other than
> > implementing OSGi in the VM, I don't see how to avoid this.
> >
> > The multiplicity of bootstrap classloaders still needs to be hidden
> > since the API demands that getClassLoader should return null for the
> > bootstrap classloader(s).
> >
> > The biggest problem is probably how to implement this as VM-independent
> > API such that a VM wanting to implement OSGi had to provide only a
> > minimal C/Java interface in order to gain OSGi support.
> >
> > Regards,
> > Mark.
> >
> > > I will look more closely on this problems and let you know if there some
> > > progresses made.
> > > Thanks a lot !
> >
> > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> > >
> > > > I do not know osgi model in detail, but what minimal set of classes is
> > > > needed to start osgi model itself? Then we could delegate to "system"
> > > > bundle loader from bootstrap classloader.
> > > >
> > > > 2009/5/18, tian galaxy <ha...@gmail.com>:
> > > > > Yes , implement osgi loading model in there is too complex.
> > > > >
> > > > > We know some modules are more important than others , performing some
> > > > > fundamental , basic functions .
> > > > > Is it possible to only load these more" basic " modules with
> > bootstrap
> > > > class
> > > > > loader and make the other modules work the osgi bundle?
> > > > > Actually I don't quite understand why system classes could only be
> > loaded
> > > > by
> > > > > bootstrap class loader?I noticed that there are some safety concerns
> > > > > ,is there any reasons other than that?
> > > > > Thanks !
> > > > >
> > > > >
> > > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> > > > >
> > > > >> Short answer is "no". You'll have to implement osgi loading model
> > > > >> inside bootstrap classloader. Is it too complex?
> > > > >>
> > > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
> > > > >> > Hi Pavel.
> > > > >> >
> > > > >> > Thanks.
> > > > >> > Yes ,that's right .My question is whether there is a way to load
> > the
> > > > >> system
> > > > >> > class by class loader other than the bootstrap class loader ?
> > > > >> > If we could load the system class by different loaders other than
> > the
> > > > >> > bootstrap class loader then there is a chance to make the harmony
> > > > >> > runtime
> > > > >> to
> > > > >> > be osgi-ed.
> > > > >> > I trying to work on this problem . Do you have any suggestions ?
> > > > >> >
> > > > >> >
> > > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> > > > >> >
> > > > >> >> Tian,
> > > > >> >> System classes are all loaded with bootstrap classloader. It is
> > > > >> >> written in C++ and is located in
> > > > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
> > > > >> >>
> > > > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
> > > > >> >> > Hi all
> > > > >> >> > I have a question about the classloading in the drlvm.
> > > > >> >> >
> > > > >> >> > I know that there are kernel library inside the drlvm such as
> > > > >> >> > java.lang.classloader, which enclose the the systemclassloader.
> > And
> > > > >> this
> > > > >> >> > class is loaded and used in the process of creating VM .
> > > > >> >> > While the systemclassloader is a subtype of urlclassloader
> > which is
> > > > >> >> > in
> > > > >> >> the
> > > > >> >> > "luni" module.So does the JNI_CreateJavaVM
> > > > >> >> > also load the urlclassloader in the boot procedure of vm ?(I
> > failed
> > > > >> >> > to
> > > > >> >> > search related code in the source code of drlvm).
> > > > >> >> > If so , when ?Before or after the jni available ?
> > > > >> >> > Since I am trying to implement the osgi on harmony and the osgi
> > > > works
> > > > >> >> with
> > > > >> >> > bundles (modules) , I think I need to know the procedure of
> > booting
> > > > >> and
> > > > >> >> > loading of class from different modules at the start up time.
> > > > >> >> > Any clue about this ?Thanks
> > > > >> >> >
> > > > >> >> > plus,do we have the source code of java.exe ?Where?
Re: Question about the boot and classloading
Posted by tian galaxy <ha...@gmail.com>.
Hindess .Thanks for the help ! I realized that this far more complex than I
thought before .
So I think I need a deeper look into both osgi and harmony .
Here are several things I don't qiute understand and I noted them below.May
be it's because I am not quite familiar with the low level , classloading
details .
thanks!
2009/5/19 Mark Hindess <ma...@googlemail.com>
>
> In message <df...@mail.gmail.com>,
> tian
> galaxy writes:
> >
> > OK ,thanks .Seems the minimal class set has been defined by the osgi.
>
> Not sure how this helps though. The OSGi Minimum Execution Environment
> says what is theoretically the minimum required to run OSGi. What we
> need to concern ourselves with is the *practical* minimum and that
> really depends on our implementation details.
>
> I don't think that we should implement OSGi in the VM. Instead the
> existing bootstrap classloader should load the OSGi framework (with
> a unique classloader)
If we load the osgi with the bootstrap class loader , why comes a unique
class loader?
Do you mean the bootstrap class loader should delegate the loading to the
'unique class loader '?
and the system classes (with a "temporary"
> classloader).
Again ,the relation between temporary and bootstrap classloder ?And why
temporary ?
> Once the OSGi framework is configured the system classes
> need to be moved to the correct classloader for the OSGi bundle to which
> they belong.
>
> This means that during the initial starting-OSGi-framework phase
> the OSGi bundle import/exports will not be enforced
but, other than
> implementing OSGi in the VM, I don't see how to avoid this.
>
> The multiplicity of bootstrap classloaders still needs to be hidden
> since the API demands that getClassLoader should return null for the
> bootstrap classloader(s).
>
> The biggest problem is probably how to implement this as VM-independent
> API such that a VM wanting to implement OSGi had to provide only a
> minimal C/Java interface in order to gain OSGi support.
>
> Regards,
> Mark.
>
> > I will look more closely on this problems and let you know if there some
> > progresses made.
> > Thanks a lot !
>
> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> >
> > > I do not know osgi model in detail, but what minimal set of classes is
> > > needed to start osgi model itself? Then we could delegate to "system"
> > > bundle loader from bootstrap classloader.
> > >
> > > 2009/5/18, tian galaxy <ha...@gmail.com>:
> > > > Yes , implement osgi loading model in there is too complex.
> > > >
> > > > We know some modules are more important than others , performing some
> > > > fundamental , basic functions .
> > > > Is it possible to only load these more" basic " modules with
> bootstrap
> > > class
> > > > loader and make the other modules work the osgi bundle?
> > > > Actually I don't quite understand why system classes could only be
> loaded
> > > by
> > > > bootstrap class loader?I noticed that there are some safety concerns
> > > > ,is there any reasons other than that?
> > > > Thanks !
> > > >
> > > >
> > > > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> > > >
> > > >> Short answer is "no". You'll have to implement osgi loading model
> > > >> inside bootstrap classloader. Is it too complex?
> > > >>
> > > >> 2009/5/18, tian galaxy <ha...@gmail.com>:
> > > >> > Hi Pavel.
> > > >> >
> > > >> > Thanks.
> > > >> > Yes ,that's right .My question is whether there is a way to load
> the
> > > >> system
> > > >> > class by class loader other than the bootstrap class loader ?
> > > >> > If we could load the system class by different loaders other than
> the
> > > >> > bootstrap class loader then there is a chance to make the harmony
> > > >> > runtime
> > > >> to
> > > >> > be osgi-ed.
> > > >> > I trying to work on this problem . Do you have any suggestions ?
> > > >> >
> > > >> >
> > > >> > 2009/5/18 Pavel Pervov <pm...@gmail.com>
> > > >> >
> > > >> >> Tian,
> > > >> >> System classes are all loaded with bootstrap classloader. It is
> > > >> >> written in C++ and is located in
> > > >> >> working_vm/vm/vmcore/src/class_support/classloader.cpp
> > > >> >>
> > > >> >> 2009/5/17, tian galaxy <ha...@gmail.com>:
> > > >> >> > Hi all
> > > >> >> > I have a question about the classloading in the drlvm.
> > > >> >> >
> > > >> >> > I know that there are kernel library inside the drlvm such as
> > > >> >> > java.lang.classloader, which enclose the the systemclassloader.
> And
> > > >> this
> > > >> >> > class is loaded and used in the process of creating VM .
> > > >> >> > While the systemclassloader is a subtype of urlclassloader
> which is
> > > >> >> > in
> > > >> >> the
> > > >> >> > "luni" module.So does the JNI_CreateJavaVM
> > > >> >> > also load the urlclassloader in the boot procedure of vm ?(I
> failed
> > > >> >> > to
> > > >> >> > search related code in the source code of drlvm).
> > > >> >> > If so , when ?Before or after the jni available ?
> > > >> >> > Since I am trying to implement the osgi on harmony and the osgi
> > > works
> > > >> >> with
> > > >> >> > bundles (modules) , I think I need to know the procedure of
> booting
> > > >> and
> > > >> >> > loading of class from different modules at the start up time.
> > > >> >> > Any clue about this ?Thanks
> > > >> >> >
> > > >> >> > plus,do we have the source code of java.exe ?Where?
> > > >> >> >
> > > >> >> > --
> > > >> >> > Regards
> > > >> >> > Michael Tian
> > > >> >> >
> > > >> >>
> > > >> >
> > > >> >
> > > >> >
> > > >> > --
> > > >> > Regards
> > > >> > Michael Tian
> > > >> >
> > > >>
> > > >
> > > >
> > > >
> > > > --
> > > > Regards
> > > > Michael Tian
> > > >
> > >
> >
> >
> >
> > --
> > Regards
> > Michael Tian
> >
> > --0016363ba4b87ec6cc046a2f8544--
> >
>
>
>
--
Regards
Michael Tian