Greets, I found a critical Java NIO flaw in Honeycomb / Android 3.0.
If "duplicate()" is called on a Buffer and that duplicate view is used to write to the buffer data integrity is not guaranteed. This is a regression for Honeycomb only at this point. I got stuck with a ~45 hour debug cycle to catch this as it affected my usage of the NIO and the OpenGL ES API resulting in no rendering due to bad data. Unfortunately any usage of the NIO API and duplicate() will cause problems regardless if it's networking, other JNI usage, etc. This is a critical NIO flaw. Please vote for this issue as it's critical and could affect a lot of code out there; not just mine... http://code.google.com/p/android/issues/detail?id=16434&colspec=ID%20Type%20Status%20Owner%20Summary%20Stars For fun you can read about the "pain and horror" this caused me: http://groups.google.com/group/android-developers/browse_thread/thread/de2db3978f33e825/176743696efd56c9#176743696efd56c9 Test Example: On all Java / J2SE platforms 1.4, 5.0, 6.0 and Android OS version 1.0 - 2.3 the value of index 1 of buffer & buffer2 is 0x10000 (65535). On Android 3.0 / Honeycomb index 1 of buffer is 65535 and buffer 2 is 256.. Clearly a major if not critical flaw in Honeycomb for usage of the NIO API and calling duplicate() on a Buffer. Any code using NIO and duplicate() will likely break on Honeycomb. --------------------- package com.egrsoftware.niotest; import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.nio.IntBuffer; / ** * NIOTest - Extremely simple unit test that Google should include in Android because it catches a bug in NIO that is * found in Android 3.0 / Honeycomb. This is a really nefarious bug as the affected code could be networking code, any * native JNI code, or in my case 3D rendering via the Android OpenGL ES API. Any code using NIO and "duplicate()" is * broken. * * On all Java platforms with NIO and Android versions 1.0 to 2.3 both buffers should print out 65535. On Android / * Honeycomb the 1st value in buffer 1 is 65535 and buffer 2 is 256!!!! Clearly a bug that any simple unit testing * should have found. This bug affects _ALL_ code that uses the NIO duplicate() method on a Buffer. The fall out of * this is immense! This is a critical bug! */ public class NIOTest { private static int s_SIZE_OF_INT = 4; public static void test() { IntBuffer buffer = ByteBuffer.allocateDirect(1 * s_SIZE_OF_INT).order( ByteOrder.nativeOrder()).asIntBuffer(); IntBuffer buffer2 = ByteBuffer.allocateDirect(1 * s_SIZE_OF_INT).order( ByteOrder.nativeOrder()).asIntBuffer(); IntBuffer bufferWrite2 = buffer2.duplicate(); buffer.put(0, 0x10000); //put 65535 bufferWrite2.put(0, 0x10000); System.err.println("NIOTest ----------"); System.err.println("buffer.get(): " +buffer.get()); System.err.println("buffer2.get(): " +buffer2.get()); } public static void main(String args[]) { test(); } } -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
