Bug 7181756

[Krystal Mo]

Just ran your test case on JDK7u9 (which is just released this week) and 
by default settings the bug wouldn't reproduce anymore.

As mentioned in last mail, the full fix will be sent out for review 
later this week.

- Kris

On 2012/10/17 5:39, Krystal Mo wrote:
> 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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