RFR: 8189633: Missing -Xcheck:jni checking for DeleteWeakGlobalRef

[Kim Barrett]

> On Jan 5, 2018, at 1:04 AM, Kim Barrett <kim.barrett at oracle.com> wrote:
> 
>> On Jan 3, 2018, at 12:31 AM, David Holmes <david.holmes at oracle.com> wrote:
>> 
>> Hi Kim,
>> 
>> On 3/01/2018 9:30 AM, Kim Barrett wrote:
>>> Please review this change to the checking form of DeleteWeakGlobalRef
>>> to actually perform some checking.  The checking that is now being
>>> done was cribbed from DeleteGlobalRef.
>>> CR:
>>> https://bugs.openjdk.java.net/browse/JDK-8189633
>>> Webrev:
>>> http://cr.openjdk.java.net/~kbarrett/8189633/open.00/
>> 
>> Doesn't the fact it is a weak-ref mean that resolving it could return NULL, in which case validate_object will trigger a JNI fatal error:
>> […]
> 
> You’re right.  I thought I’d used validate_handle, but obviously not.
> 
> I think I should leave this issue alone for now, and come back to it after JDK-8194312 is done.
> There are some changes to jniCheck there already, and I think some more, like here, can
> be simplified or improved by relying on the JDK-8194312 changes to JNIHandles.

Finally getting back to this.

full: http://cr.openjdk.java.net/~kbarrett/8189633/open.01/
incr: http://cr.openjdk.java.net/~kbarrett/8189633/open.01.inc/

Testing:
mach5 tier1-3.
local tier1 with -Xcheck:jni (thanks for fixing JDK-8189766, David).
Reported JDK-8229900 (a tier1 failure with -Xcheck:jni that is unrelated to this change).