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

[David Holmes]

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
>