RFR [8022584] Memory leak in some NetworkInterface methods

[David Holmes]

Main fix looks good to me.

Regression test may need some tweaking eg I think othervm will be needed.

Also this:

  System.out.println("WARNING: Cannot perform memory leak detection on 
this OS");

should probably just say something like "Test skipped on this OS" - 
there are other tests that do this so just check if there is common 
terminology. (In the future we may have keyword tags to flag this as 
linux only etc.)

Thanks,
David

On 9/08/2013 4:41 AM, Ivan Gerasimov wrote:
> Chris, if it's not too late, I'd like to include a regtest in the fix.
>
> Here's webrev that includes the test:
> http://cr.openjdk.java.net/~igerasim/8022584/3/webrev/
>
> The test gets past with the fixed jdk8 and fails with jdk8-b101 and jdk7
> as expected.
>
> Sincerely yours,
> Ivan
>
> On 08.08.2013 17:50, Chris Hegarty wrote:
>> Looks good to me. Thanks Ivan.
>>
>> -Chris.
>>
>> On 08/08/2013 02:33 PM, Ivan Gerasimov wrote:
>>> Hello Chris!
>>>
>>> Here's the update:
>>> http://cr.openjdk.java.net/~igerasim/8022584/2/webrev/
>>>
>>> Thanks for offering the sponsorship!
>>> Here's the hg-export
>>> http://cr.openjdk.java.net/~igerasim/2commit/8022584-jdk8-Memleak-in-NetworkInterface.patch
>>>
>>>
>>>
>>> Sincerely yours,
>>> Ivan
>>>
>>> On 08.08.2013 12:43, Chris Hegarty wrote:
>>>> Thanks for taking this Ivan.
>>>>
>>>> Can you please make the changes suggested by both David and Alan (
>>>> simply return NULL/-1/JNI_FALSE, as appropriate, if GetStringUTFChars
>>>> fails ( returns NULL ), then I will sponsor this change into jdk8 for
>>>> you.
>>>>
>>>> Please post an update webrev to cr.openjdk.java.net.
>>>>
>>>> -Chris.
>>>>
>>>> On 08/08/2013 06:01 AM, David Holmes wrote:
>>>>> Ivan,
>>>>>
>>>>> On 8/08/2013 2:05 PM, Ivan Gerasimov wrote:
>>>>>> David, Alan,
>>>>>>
>>>>>> I added checking for NULL  results and throwing OOMException if
>>>>>> necessary.
>>>>>
>>>>> You don't need to throw it yourself:
>>>>>
>>>>>    JNU_ThrowOutOfMemoryError(env, NULL);
>>>>>
>>>>> Assuming a correct VM implementation if NULL is returned then an OOME
>>>>> should already be pending and will be thrown as soon as your native
>>>>> code
>>>>> returns to Java.
>>>>>
>>>>> Thanks,
>>>>> David
>>>>>
>>>>>> I've also added some spaces along the code to improve indentation.
>>>>>>
>>>>>> Would you please review the updated webrev?
>>>>>> http://washi.ru.oracle.com/~igerasim/webrevs/8022584/1/webrev/
>>>>>>
>>>>>> Sincerely yours,
>>>>>> Ivan
>>>>>>
>>>>>>
>>>>>> On 08.08.2013 5:35, David Holmes wrote:
>>>>>>> On 8/08/2013 11:20 AM, Ivan Gerasimov wrote:
>>>>>>>> Thanks Alan!
>>>>>>>>
>>>>>>>> I've checked that and it turns out that GetStringUTFChars cannot
>>>>>>>> return
>>>>>>>> NULL.
>>>>>>>> For allocation of the result string it calls AllocateHeap() with
>>>>>>>> the
>>>>>>>> default EXIT_OOM fail strategy.
>>>>>>>> Thus, in case of being unable to allocate memory it simply stops
>>>>>>>> VM.
>>>>>>>
>>>>>>> Ouch! That is a hotspot bug. GetStringUTFChars is supposed to throw
>>>>>>> OutOfMemoryError if it has memory issues, not abort the VM!
>>>>>>>
>>>>>>> I recommend that you check for NULL and/or a pending exception.
>>>>>>>
>>>>>>> David
>>>>>>>
>>>>>>>> Sincerely yours,
>>>>>>>> Ivan
>>>>>>>>
>>>>>>>> On 08.08.2013 5:05, Alan Bateman wrote:
>>>>>>>>> (cc'ing net-dev).
>>>>>>>>>
>>>>>>>>> The change looks okay to me. One suggestion (while you are
>>>>>>>>> there) is
>>>>>>>>> to check the return from  GetStringUTFChars so that the name
>>>>>>>>> returns
>>>>>>>>> when it fails with NULL.
>>>>>>>>>
>>>>>>>>> -Alan.
>>>>>>>>>
>>>>>>>>> On 07/08/2013 17:46, Ivan Gerasimov wrote:
>>>>>>>>>> Hello everybody!
>>>>>>>>>>
>>>>>>>>>> Some methods of NetworkInterface class were reported to leak
>>>>>>>>>> memory.
>>>>>>>>>> http://bugs.sun.com/view_bug.do?bug_id=JDK-8022584 (not yet
>>>>>>>>>> available.)
>>>>>>>>>>
>>>>>>>>>> Examples are isUp() and isLoopback().
>>>>>>>>>>
>>>>>>>>>> Affected versions of jdk are 6, 7 and 8
>>>>>>>>>>
>>>>>>>>>> Would you please review a simple fix that removes the unnecessary
>>>>>>>>>> allocation?
>>>>>>>>>> http://cr.openjdk.java.net/~igerasim/8022584/0/webrev/
>>>>>>>>>>
>>>>>>>>>> Sincerely yours,
>>>>>>>>>> Ivan
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>
>>>>
>>>
>>
>>
>