MessageBuffer doesn't work on Android OS

I used MessageBuffer on Android OS(4.0.3) simulator. But these error and exceptions occurred.

05-25 02:36:36.306: E/dalvikvm(12569): Could not find class 'sun.nio.ch.DirectBuffer', referenced from method org.msgpack.core.buffer.MessageBuffer.putByteBuffer

05-25 02:36:36.347: E/AndroidRuntime(12569): FATAL EXCEPTION: main
05-25 02:36:36.347: E/AndroidRuntime(12569): java.lang.ExceptionInInitializerError
05-25 02:36:36.347: E/AndroidRuntime(12569):    at com.example.TestApp.MyActivity.onResume(MyActivity.java:186)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1185)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at android.app.Activity.performResume(Activity.java:5182)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2732)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2771)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2235)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at android.os.Looper.loop(Looper.java:137)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at android.app.ActivityThread.main(ActivityThread.java:5041)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at java.lang.reflect.Method.invokeNative(Native Method)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at java.lang.reflect.Method.invoke(Method.java:511)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at dalvik.system.NativeStart.main(Native Method)
05-25 02:36:36.347: E/AndroidRuntime(12569): Caused by: java.lang.RuntimeException: java.lang.NoSuchFieldException: theUnsafe
05-25 02:36:36.347: E/AndroidRuntime(12569):    at org.msgpack.core.buffer.MessageBuffer.<clinit>(MessageBuffer.java:77)
05-25 02:36:36.347: E/AndroidRuntime(12569):    ... 16 more
05-25 02:36:36.347: E/AndroidRuntime(12569): Caused by: java.lang.NoSuchFieldException: theUnsafe
05-25 02:36:36.347: E/AndroidRuntime(12569):    at java.lang.Class.getDeclaredField(Class.java:631)
05-25 02:36:36.347: E/AndroidRuntime(12569):    at org.msgpack.core.buffer.MessageBuffer.<clinit>(MessageBuffer.java:32)
05-25 02:36:36.347: E/AndroidRuntime(12569):    ... 16 more

I think it's not an urgent issue for now. I created this issue just FYI.

#101: Workaround for Android OS. Creating Unsafe instance by calling …

@komamitsu

Added a workaround for Android OS. @komamitsu Could you test this?

#101: Fix comments

Unsafe instance can be found by the previous commits. The next problem is to create DirectByteBuffer instances. It looks like the constructor of DirectByteBuffer is different between Android OS and Oracle JVM.

Here is a source code of DirectByteBuffer of Android:
https://android.googlesource.com/platform/libcore/+/master/luni/src/main/java/java/nio/DirectByteBuffer.java

And also sun.misc.Unsafe API is slightly different from Oracle JVM:
https://android.googlesource.com/platform/libcore/+/master/libdvm/src/main/java/sun/misc/Unsafe.java

Unsafe class in Android has not getByte(address). Instead I found libcore.io.Memory.peekByte(address):
https://android.googlesource.com/platform/libcore/+/master/luni/src/main/java/libcore/io/Memory.java

We cannot access libcore.io package and DirectByteBuffer class without using reflection. So we should provide a fallback that only uses byte[] or ByteBuffer based access methods to memory.

#101 Added several workarounds for Android OS, but this implementatio…

Is there any update about this issue? I encounters exactly same issue.

I'll add MessageBufferU(niversal) class, which does not depend on Unsafe and DirectByteBuffer classes.

@xerial

@xerial
Thanks for your work on android support.
String bufferClsName; if(isJavaAtLeast7) { if(isLittleEndian) bufferClsName = "org.msgpack.core.buffer.MessageBuffer"; else bufferClsName = "org.msgpack.core.buffer.MessageBufferBE"; } else { bufferClsName = "org.msgpack.core.buffer.MessageBufferU"; }
the code above , change to org.msgpack.core.buffer.MessageBufferX.class is better.
It can't be used for proguard, when you use class String.

@axeon

@axeon
The above switch is necessary for avoiding generation of TypeProfile for MessageBuffer methods, which is a key to achieve good performance in platform other than Android.

Is there any option in proguard to force include MessageBufferU class?

For example, I found
http://stackoverflow.com/questions/7464035/how-to-tell-proguard-to-keep-everything

@xerial

@xerial
the new version is ok on android, but logcat print too many exception such as "can't find class sun.nio.ch.DirectBuffer/sun.misc,Unsafe".
on andorid platform ,the java.specification.version is 0.9.

I think we can add MessageBufferFactory or other class to switch MessageBuffer class, it will be disable class not found exception .

In addition ,these code is tested in android .

       Class<?> bufferCls = null;
        if(isJavaAtLeast7) {
            if(isLittleEndian)
                bufferCls = org.msgpack.core.buffer.MessageBuffer.class;
            else
                bufferCls = org.msgpack.core.buffer.MessageBufferBE.class;
        }
        else {
            bufferCls = org.msgpack.core.buffer.MessageBufferU.class;
        }

        msgBufferClass = bufferCls;

@axeon

@axeon
Our design decision is that we never create any interface for MassageBuffer class, because interface adds overhead to every method call due to invokeinterface call and TypeProfile generation. Speed has been the most important factor in designing msgpack v07.

Even if we create a factory class, it still needs to load MessageBuffer class (since it is a base class) and will show the warning messages you observed.

Thanks for java.specification.version information. The msgpack-core-0.7.0-p4 now uses isAndroid flag:

msgpack-java/msgpack-core/src/main/java/org/msgpack/core/buffer/MessageBuffer.java

Line 122 in 629f0b3

if(!isAndroid && isJavaAtLeast7) {

@xerial

@xerial
Thanks for your works.
Maybe we can use MessageBufferU as base class, when detected optimized conditions is ok, then switch to MessageBufferOpt(MessageBuffer now).
This solution will be balanced performance and aesthetic design .

@axeon

@axeon
FYI. If JVM finds two or more classes that defines a method, it will generate TypeProfile. Simply writing import MessageBufferU in a code results in generation of TypeProfile and ends up slowing down method calls of MessageBuffer.

So we cannot make MessageBufferU.getByte a base class of MessageBuffer.getByte.

For reducing warning message, we should create a different ticket and maybe worth considering to create a separate build for Android platform.

Thanks!

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MessageBuffer doesn't work on Android OS #101

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xerial commented on May 26, 2014

xerial commented on May 26, 2014

xerial commented on May 26, 2014

xerial commented on May 26, 2014

xerial commented on May 26, 2014

xerial commented on May 26, 2014

timnew commented on Jan 14, 2015

xerial commented on Jan 15, 2015

axeon commented on Jan 19, 2015

xerial commented on Jan 19, 2015

xerial commented on Jan 19, 2015

axeon commented on Jan 19, 2015

xerial commented on Jan 19, 2015

axeon commented on Jan 19, 2015

xerial commented on Jan 19, 2015

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