Sure. I've posted from mobile, and my multitap betrayed me. Thanks, Mark.
2009/5/20, Mark Hindess <[email protected]>: > > In message <[email protected]>, > 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 <[email protected]>: >> > 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 <[email protected]> >> > >> >> On Tue, May 19, 2009 at 6:41 PM, Mark Hindess >> >> <[email protected]> wrote: >> >> > >> >> > In message >> >> > <[email protected]>, >> >> 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 <[email protected]> >> >> >> > >> >> >> > In message < >> >> [email protected]>, >> >> >> > 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 <[email protected]> >> >> >> > > >> >> >> > > > 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 <[email protected]>: >> >> >> > > > > 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 <[email protected]> >> >> >> > > > > >> >> >> > > > >> Short answer is "no". You'll have to implement osgi loading >> >> model >> >> >> > > > >> inside bootstrap classloader. Is it too complex? >> >> >> > > > >> >> >> >> > > > >> 2009/5/18, tian galaxy <[email protected]>: >> >> >> > > > >> > 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 <[email protected]> >> >> >> > > > >> > >> >> >> > > > >> >> 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 <[email protected]>: >> >> >> > > > >> >> > 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 >> > >> > > >
