Sergey, interesting comments. Startup is surely a topic that should be addressed. Your comments are helpful.
I am not very sure about the footprint. Does Harmony have a solution for small footprint? What is "With the Kernel distribution it's only 3MB"? Thanks. -xiaofeng On Tue, Apr 29, 2008 at 3:17 AM, Sergey Salishev <[EMAIL PROTECTED]> wrote: > Hi, > > Alexey, thanks for the link. I don't think the distribution size is the > biggest JRE problem for client applications. Anyway even without Kernel > distribution RE JRE is only 15MB which is substantially smaller than .NET > framework redistributable. With the Kernel distribution it's only 3MB about > 2x Flash Player size :) > > JRE's three biggest problems I think are slow startup, large footprint and > GC pauses. The footprint problem is generally solved by data sharing between > JVM instances. The GC pauses can be helped by using incremental or > concurrent GC. > > The startup time tougher problem. It's almost unrelated to the ditribution > size as only the used classes are loaded. But it's governed by the class > parsing and no-opt JIT/interpreter overhead. It's possible to make JRE > startup to be more lean and mean. But the real answer here is excluding the > classloading and JIT phase from startup altogether at least for frequently > used components. The good news are that most of the frequently used classes > for small applications are located in class libraries. RE JRE as I remember > already can precompile rt.jar and use that fact. .NET has a signed binary > module cache and the application installer can compile the model AOT and > place it to cache. > > The bbiggest problems of AOT compiled module caching are class versioning > and security. I think it's possible to implement such mechanism for Java > using Jar files as an atomic modules for AOT caching. In this case the Jar > signature would be used for module versioning and ensuring the binary code > is unmodified. We already made some experiments and caching on individual > method level doesn't give any performance boost due to class loading and > signing overhead. > > Thanks. > Sergey. > > 2008/4/28 Alexey Petrenko <[EMAIL PROTECTED]>: > > > > > > > > http://java.sun.com/developer/technicalArticles/javase/java6u10/index.html#kernel > > > -- http://xiao-feng.blogspot.com
