Comments on: VM issues with Samsung A900 http://www.agilefusion.com/2007/03/01/vm-issues-with-samsung-a900/ Integrating into the future Wed, 07 Jan 2009 01:20:00 +0000 http://wordpress.org/?v=2.6 By: alexey http://www.agilefusion.com/2007/03/01/vm-issues-with-samsung-a900/#comment-6014 alexey Thu, 23 Aug 2007 23:07:36 +0000 http://www.agilefusion.com/2007/03/01/vm-issues-with-samsung-a900/#comment-6014 I believe the way Vincent fixed it, was to move all the methods into the base abstract class, "testMethod" in this case. I believe the way Vincent fixed it, was to move all the methods into the base abstract class, “testMethod” in this case.

]]> By: Andy http://www.agilefusion.com/2007/03/01/vm-issues-with-samsung-a900/#comment-6013 Andy Thu, 23 Aug 2007 22:59:13 +0000 http://www.agilefusion.com/2007/03/01/vm-issues-with-samsung-a900/#comment-6013 I encountered this problem and it seems to have gone away by me declaring all the involved classes as "abstract". I don't know how often that'll work, but it worked for me. I encountered this problem and it seems to have gone away by me declaring all the involved classes as “abstract”. I don’t know how often that’ll work, but it worked for me.

]]> By: Vincent Deschenes http://www.agilefusion.com/2007/03/01/vm-issues-with-samsung-a900/#comment-2029 Vincent Deschenes Thu, 17 May 2007 03:54:09 +0000 http://www.agilefusion.com/2007/03/01/vm-issues-with-samsung-a900/#comment-2029 The issue seems to be with a class structure fork. I believe that the the VM gets confused with a class tree as follows when methods are being called in rapid succession (e.g. when quick opcodes or a JIT might be used) Class tree: 1. EF extends DF extends C extends B -extends A 2. E extends D extends C extends B extends A Where the base class is A and all of these classes implement the method: "method1()". Class C has a method "testMethod" that calls "method1". If we have an array of elements EF and E and we rapidly iterate through it calling "testMethod". Normal operation will invoke method1 in either EF or E depending on the instance. However, I believe in the A900, the just-in-time compiler gets confused and incorrectly calls the "method1" method in "C" when there is more than one override path. The issue seems to be with a class structure fork.
I believe that the the VM gets confused with a class tree as follows when methods are being called in rapid succession (e.g. when quick opcodes or a JIT might be used)

Class tree:

1. EF extends DF extends C extends B -extends A
2. E extends D extends C extends B extends A

Where the base class is A and all of these classes implement the method: “method1()”. Class C has a method “testMethod” that calls “method1″.

If we have an array of elements EF and E and we rapidly iterate through it calling “testMethod”. Normal operation will invoke method1 in either EF or E depending on the instance. However, I believe in the A900, the just-in-time compiler gets confused and incorrectly calls the “method1″ method in “C” when there is more than one override path.

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