I'm sorry but I think you should have missed some thing in the review .the OSGi framework I use is Felix, and all the security and dynamic comes from it and built in with it, if you want to find the osgi-ed security and dynamic does this answer your question ?
2009/8/16 Jin Mingjian <jin....@gmail.com> > interesting. I'd like to mainly examine the dynamic and security of > your OSGi-Harmony runtime when the codes is ready. > > 2009/8/16 Xiao-Feng Li <xiaofeng...@gmail.com> > > > Good work! How much is the size of the minimum OSGi-ed JRE? > > > > Thanks, > > xiaofeng > > > > On Sun, Aug 16, 2009 at 3:22 PM, galaxy<tian.gal...@gmail.com> wrote: > > > Hi all > > > Now the code for OSGi-ed Runtime of Harmony is almost complete , I'd > > > like to give a review of > > > the work so far.The code and usage will be uploaded together soon > > > > > > Introduction To OSGi-ed JRE > > > > > > > > > > > > 1 : The main purpose > > > > > > OSGi has become one of the best ways to govern the jar files in a > number > > of > > > applications Such as the power it exhibits in eclipse .And as we all > know > > > ,the Harmony runtime is a modularized one and each module , with its > > > manifest file , is just like one bundle in the OSGi framework .So we > are > > > think of governing the modules in Harmony runtime in a OSGi-ed way. > > > > > > > > > > > > 2 : Ways to meet the main purpose > > > > > > Naturally, there are two ways to meet this purpose: > > > > > > A Implementing the OSGi framework in VM in C/C++ to govern all the > java > > > modules > > > > > > B Using one of the OSGi-ed framework implemented in java to > implemented > > a > > > half OSGi-ed JRE. > > > > > > Finally I picked the plan B with the well known OSGi framework > > :Felix > > > .And the reasons are as follows > > > > > > First : Implementing a OSGi-ed framework from scratch in c/c++ in the > vm > > is > > > difficult and time-consuming . > > > > > > Second : Plan A suffers from the facts that implementations differs > huge > > > from VM to VM .Plan B won’t have this kind of problem as long as the > > modules > > > comply with the OSGi specifications and we have a adapted java.exe , > the > > > rest is nearly the same. > > > > > > Third : Beside the framework ,each OSGi implementation has a lot of > > add-ons > > > .This will facilitate future development of new features and utilities > > .For > > > example : the could use the bundle fileinstall to install all the jar > > files > > > lies in a folder ,very helpful in certain circumstances.This could be > > done > > > rapidly if we choose plan B . > > > > > > > > > > > > 3 : Problems and fixes > > > > > > The difficulties ,or the main tasks ,of this project are as follows > > > > > > A Find the minimum working environment of OSGi-framework and modify > > the > > > rest modules in Harmony ,mainly the manifest file ,to resolve the > > coupling > > > > > > B Modify the classloading mechanism and booting of the jre to be > able > > > run normal java applications > > > > > > And the fixes are > > > > > > For A: > > > > > > Harmony is a modularized runtime .So determine the minimum working > > > environment is no more than choose the right module to stay with the VM > > > .However ,although the coupling is little , it does exist . So a > > > modification of the module is necessary ,mainly the manifest file .And > as > > I > > > want to remain the original structure of Harmony as largely as > possible > > > ,more contents (classes ) will be included in the minimum environment > > other > > > than splitting the modules apart .The final jre include the following > > > component : > > > > > > > > > > > > luni.jar > > > > > > annotation.jar > > > > > > security.jar > > > > > > math.jar > > > > > > text.jar > > > > > > regex.jar > > > > > > noi_char.jar > > > > > > nio.jar > > > > > > logging.jar > > > > > > concurrent.jar > > > > > > archive.jar > > > > > > the ICU4J folder. > > > > > > > > > > > > The remaining jars are governed by the OSGi framework to handle. One > more > > > thing to mention is the two classes > > > ,”java.beans.PropertyChangelinstener”,”java.beans.PropertyChangeEvent” > > has > > > to be moved out of beans.jar .This is because of the coupling of > > beans.jar > > > with other modules in the minimum runtime .Well the good thing is these > > two > > > classes havn’t imports any other classes in the modules governed by the > > OSGi > > > framework .I think we could include them in any modules lie in the > > minimum > > > runtime as long as the VM could find them . > > > > > > > > > > > > For B: > > > > > > I added one extra sphere between the VM and the main class to run > > > .org.apache.osgi.FelixStarter. , the following is done in this class > > > > > > First: Loading the configurations and Start Felix ,the OSGi framework > we > > use > > > > > > Second: Initializing the class org.apache.osgi.OsgiClassLoader ,this > > class > > > will load the main class and subsequently all the classes used in the > > main > > > class > > > > > > Third: Transfer the arguments to the “real “ main class ,invoke the > main > > > method . > > > > > > > > > > > > The sequence of class loading is as follows : > > > > > > > > > > > > First : Check the class name to determine whether it should be loaded > by > > the > > > parent class loader .This work is done by specifying the > > > “org.osgi.framework.bootdelegation” property to include all the package > > > names in the modules stays in the VM . > > > > > > Second : load the classes in the bundle governed by the framework .I > will > > > examine each bundle's export and import property to search for the > class > > > name ; > > > > > > Third : the classes in the application’s class path . > > > > > > Finally : we could not find the class and a ClassNotFoundException will > > be > > > thrown . > > > > > > > > > > > > Both the OSGi framework and the Harmony do not allow the define , > imports > > or > > > exports of java.* classes and packages ,so a lot of examines has been > > > removed to facilitate our purpose . > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > regards > > > Tian > > > > > > > > > > > -- > > http://people.apache.org/~xli > > > -- regards Tian
