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Subject: Re: java.lang.String class in Dalvik - msg#00076
List: android-platform
On Jun 2, 7:37 pm, Mercury <bao...@xxxxxxxxx> wrote:
> As I found that at the current, the methods of java.lang.String class
> of Dalvik are mostly implemented by Java code and maybe it makes the
> performance reduce. So my thinking is that can we move the
> implementation to JNI to improve performance?
Four String methods -- charAt, compareTo, equals, and length -- are
"inlined" by the VM, and are not going to get much faster.
There are probably a few others that could benefit from this
treatment, but I'm guessing that most string-centric processing in
Java will likely be dominated by the cost of String allocations. (The
above weren't inlined because of a measured performance need -- the
inlining was an experiment that needed a test subject.)
At any rate, converting to JNI is likely counter-productive. It's
more expensive to invoke a native JNI method than a virtual method,
and the native code has to issue JNI calls to access the various
fields in String. Many common operations on short strings would
actually take longer.
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binder documentation
Is there any documentation for how android binder works, specially for
the file /kernel/drivers/android/binder.c This is a very big file to
read.
Thanks!
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"Building For Dream" 1.5
Hi,
First of all, my goal is to build my own android 1.5 platform with
some modification, and deploy it on HTC Dream phone, as some other
people already did. ( http://jf.andblogs.net/ ) So, I searched this
group (and others), and it seems that there's no easy way to do that.
Is it correct?
Then I just tried with the kernel version of 2.6.27 while untouching
everything else as in the guild line (
http://source.android.com/documentation/building-for-dream
). It compiled well, but when I flashed out this image to the phone,
it's totally unusable. HOME key doesn't work, and WiFi doesn't either.
Does anyone know how to get around this? More specifically, if anybody
knows how to build and deploy custom image from the android source, I
would appreciate it.
Thanks,
Sunghwan
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java.lang.String class in Dalvik
Hi everybody,
As I found that at the current, the methods of java.lang.String class
of Dalvik are mostly implemented by Java code and maybe it makes the
performance reduce. So my thinking is that can we move the
implementation to JNI to improve performance?
If anybody has experience about that could you share with me about the
implementation, the complicate part of it...?
Thank you,
BR,
Mercury
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JNI in Dalvik
Dear everybody,
Could you show me any documents about JNI in Dalvik like how to
implement a JNI function from Java, the variable type in JNI...
Thank you
Mercury
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