RFR[10] 8190984 : tools/launcher/TestXcheckJNIWarnings.java WARNING was found in the output

[David Holmes]

On 13/12/2017 10:41 AM, Brent Christian wrote:
> What David said. :)
> 
> One other wrinkle: I ProblemList-ed the test a few days ago[1] in 

I forgot about that :(

> jdk/jdk.  AFAICT, that change is not yet in jdk/hs, so the changes 
> David's pushing can't be used to take the test back off of the 
> ProblemList.  I figure I'll have to file a new issue, to be fixed in 
> jdk/jdk (unless someone has a better idea).

I will see if we can re-sync to hs before I push the changes. Otherwise 
I could switch everything to jdk/jdk. Otherwise a new issue will need to 
be filed.

Thanks,
David

> Thanks,
> -Brent
> 
> 1. http://hg.openjdk.java.net/jdk/jdk/rev/b9a19d1e61f2
> 
> On 12/12/17 4:18 PM, David Holmes wrote:
>>
>> IIRC Brent instrumented the localref methods to see how many were 
>> being created, and the "50" gives us sufficient capacity. The actual 
>> number of local refs introduced seems to be platform and locale specific.
>>
>> Note this only affects the warnings that -Xcheck:jni produces (at 
>> least on hotspot). If more properties are added that take us beyond 
>> the new capacity then we'll see test failures again and can increase 
>> it further.
>>
>> Thanks,
>> David
>>
>>> Mandy
>>>
>>> On 12/12/17 4:00 PM, David Holmes wrote:
>>>> Reviewed! :)
>>>>
>>>> Thanks Brent!
>>>>
>>>> I guess I can push these both now.
>>>>
>>>> David
>>>>
>>>> On 13/12/2017 9:38 AM, Brent Christian wrote:
>>>>> Hi,
>>>>>
>>>>> Please review this small change to the System.initProperties() 
>>>>> native method.
>>>>>
>>>>> The tools/launcher/TestXcheckJNIWarnings.java has begun to fail due 
>>>>> to this warning being issued:
>>>>>
>>>>> WARNING: JNI local refs: 41, exceeds capacity: 40
>>>>>          at java.lang.System.initProperties(java.base/Native Method)
>>>>>          at java.lang.System.initPhase1(java.base/System.java:1943)
>>>>>
>>>>> This has only been seen on solaris-sparc with LANG=C.  In fact, the 
>>>>> warning can also be seen with a simple HelloWorld program, run with 
>>>>> -Xcheck:jni.  This started happening as of JDK-8043224 
>>>>> ("-Xcheck:jni improvements to exception checking and excessive 
>>>>> local refs").
>>>>>
>>>>> The following change should be made to prevent the warning:
>>>>>
>>>>> diff -r ed1bb7743b3e src/java.base/share/native/libjava/System.c
>>>>> --- a/src/java.base/share/native/libjava/System.c    Tue Dec 12 
>>>>> 19:05:02 2017 +0100
>>>>> +++ b/src/java.base/share/native/libjava/System.c    Tue Dec 12 
>>>>> 15:21:03 2017 -0800
>>>>> @@ -186,6 +186,9 @@
>>>>>       jobject ret = NULL;
>>>>>       jstring jVMVal = NULL;
>>>>>
>>>>> +    if ((*env)->EnsureLocalCapacity(env, 50) < 0) {
>>>>> +        return NULL;
>>>>> +    }
>>>>>       sprops = GetJavaProperties(env);
>>>>>       CHECK_NULL_RETURN(sprops, NULL);
>>>>>
>>>>>
>>>>> Of note: an additional change is needed, to EnsureLocalCapacity 
>>>>> itself:
>>>>>
>>>>> 8193222 : EnsureLocalCapacity() should maintain capacity requests 
>>>>> through multiple calls
>>>>>
>>>>> That fix has already been proposed and reviewed.
>>>>> These two fixes should be pushed together via hs, which David has 
>>>>> kindly offered to do, pending code review approval of my change here.
>>>>>
>>>>> Thanks,
>>>>> -Brent
>>>>>
>>>