Bug 7181756

[Krystal Mo]

Hi Adam,

I'm working on it and will send the fix out for review this week. Sorry 
for not reacting promptly enough for this issue.

The latest CPU releases of JDK should have temporarily disabled the 
faulting optimizations already.

Regards,
Kris

On 2012/10/17 5:31, Adam Hawthorne wrote:
> Hi all,
>
> Apologies for a -use question on a -dev list, but I couldn't find the 
> -use list ...
>
> A colleague of mine just ran into this bug:
>
> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7181756
> "Non-zero initial values in a byte array - regression in Java 7"
>
> This seems like a pretty serious issue; a subsequent search found four 
> instances in our own source code that could potentially trigger the 
> issue.  Has it seen any attention?  We did some testing and it appears 
> it was introduced with hs23 in 7u4.
>
> A simple test (based on the sample in the bug) will reproduce:
>
>
> import java.util.*;
>
> class TestBug2 {
>     public static void main(String[] argv) {
>         TestBug2 bug = new TestBug2();
>         for (int i = 0; i < 10000000; ++i) {
>             bug.testBug(i);
>         }
>     }
>
>     private void testBug(int iter) {
>         byte[] buf8 = new byte[8];
>         for (byte b : buf8) {
>             if (b != 0)
>                 throw new Error(iter + ": " + b);
>         }
>         Arrays.fill(buf8, (byte) 0);
>     }
> }
>
> // Output:
> // Exception in thread "main" java.lang.Error: 1346815: 50
> //         at TestBug2.testBug(TestBug2.java:15)
> //                 at TestBug2.main(TestBug2.java:7)
> //
>
> The above output is on Linux x64
>
> java -version:
>
> java version "1.7.0_07"
> Java(TM) SE Runtime Environment (build 1.7.0_07-b10)
> Java HotSpot(TM) 64-Bit Server VM (build 23.3-b01, mixed mode)
>
>
> Yes, I know this isn't a list to receive support, etc., I'm just 
> surprised at its current priority of low.
>
> Thanks for your attention,
>
> Adam
>
> -- 
> Adam Hawthorne
> Software Architect
> BASIS International Ltd.
> www.basis.com <http://www.basis.com>
> +1.505.938.6169 Phone
> +1.505.750.4128 Direct
>
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