<AWT Dev> RFR: [XS] 8214380: AwtDragSource function LoadCache misses a ReleaseLongArrayElements in special case

[Baesken, Matthias]

Hi Sergey,   I  think it is (at least)  a good practice  to NULL -  check  the result  of  env->GetLongArrayElements .
Probably it should be done  right after  the

     jlong *lFormats = env->GetLongArrayElements(formats, &isCopy),

call.
See  jdk/src/java.base/unix/native/libjava/ProcessHandleImpl_unix.c   for examples of usages   of the function (with NULL checks) .

Or see the documentation at   https://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/functions.html
Where we find :


Get<PrimitiveType>ArrayElements Routines
   ....
PARAMETERS:
 
env: the JNI interface pointer.
array: a Java string object. 
isCopy: a pointer to a boolean.
 

RETURNS:
 
Returns a pointer to the array elements, ****or NULL if the operation fails.****


So returning NULL might  happen .

Best regards, Matthias



> -----Original Message-----
> From: Sergey Bylokhov <Sergey.Bylokhov at oracle.com>
> Sent: Donnerstag, 29. November 2018 00:22
> To: Baesken, Matthias <matthias.baesken at sap.com>; awt-
> dev at openjdk.java.net
> Subject: Re: <AWT Dev> RFR: [XS] 8214380: AwtDragSource function
> LoadCache misses a ReleaseLongArrayElements in special case
> 
> Hi, Matthias.
> 
> Do we need the null check in the fix, if "yes" then probably
> the same check should be added before this line as well?
>    465     env->ReleaseLongArrayElements(formats, saveFormats, 0);
> 
> On 28/11/2018 00:33, Baesken, Matthias wrote:
> > Hello, please review  this small fix.
> >
> > It adds a missing ReleaseLongArrayElements  to
> >
> > void AwtDragSource::LoadCache(jlongArray formats)
> >
> > in an early special   "pseudo return"  (leave function via throw)  case.
> >
> > Webrev/bug :
> >
> > http://cr.openjdk.java.net/~mbaesken/webrevs/8214380.0/
> >
> > https://bugs.openjdk.java.net/browse/JDK-8214380
> >
> > Thanks, Matthias
> >
> 
> 
> --
> Best regards, Sergey.