I'll break your post down to get to the points: On Wed, Apr 7, 2010 at 11:45 AM, Nanard <[email protected]> wrote: > I think there is a level between the application in Java (home & app) > and the harware : the drivers are of course in C, and the JVM.
You do not have a JVM on your Android phone. The level between is the "Android Runtime", and includes the Dalvik VM: http://sites.google.com/site/edwardcraighyatt/_/rsrc/1254009753190/projects/custom-android-phone/android_sw.png > > If you compare Android devices with all other devices, we have more > 'level of software' in Android devices : > > drivers C : Android and others > OS + libraries C : Android and others > > JVM : Android > Garbage Collector : Android This last bit is wrong. As stated, there is no JVM. The garbage collector has a part to play in performance issues, but a large percentage of those problems are software design issues (e.g. overloading the heap with lots of String objects in a loop is a common mistake - the GC often kicks in to avoid OutOfMemory errors), rather than general GC performance. > > App : 'interpreted' for Android direct machine language code for > other app. Both Java and Android applications are not interpreted. You use a compiler called javac to compile the source files into bytecode (again, Dalvik (Android) bytecode is different to Java bytecode). Read http://en.wikipedia.org/wiki/Bytecode for more info on this process. > > > Even when playing a video/audio : the decoding should be done in C, > but when interfacing with 'home/UI' : it go to Java ... The decoding is done completely in C. Using the OpenCore media framework. http://www.scribd.com/doc/16917356/Mastering-the-Android-Media-Framework > Android devices can never match the speed .. of course you an always > add CPU Mhz... I disagree, there are obvious UI glitches in the existing phones, but none of them point directly to Android performance. There are some arguments that the background tasks can interfere with the UI at times, but in general the UI glitches are unrelated to the Dalvik VM. > At least : we (developer) have a wide range of devices ... THAT's the > good point of Android vs the others :-) Very true. -- You received this message because you are subscribed to the Google Groups "Android Discuss" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/android-discuss?hl=en.
