RFR: 8177136: Caller sensitive methods Logger.getLogger, Logger.getAnonymousLogger, and System.getLogger should throw IllegalCallerException if there is no caller on the stack.

[David Holmes]

On 20/03/2017 10:56 PM, Daniel Fuchs wrote:
> On 20/03/2017 12:37, David Holmes wrote:
>> What about those API's says there has to be a Java frame higher up. Why
>> can't an attached thread request a reference to the logger?
>
> Hi David,
>
> Did you look at the webrev?
>
> 1582      * @throws IllegalCallerException if there is no caller frame,
> i.e.
> 1583      *         when this {@code getLogger} method is called from JNI
> 1584      *         and there is no Java frame on the stack.
>
> This says there must be a frame higher up.

Yes but that is what you are adding. Given the basic method spec:

"Returns an instance of {@link Logger Logger} for the caller's use."

There is nothing about that which suggests any reason why the caller 
must have a Java frame on their stack to make the call!

> In the case of System.getLogger then the reason is that this
> method eventually calls  LoggerFinder.getLogger(name, module),
> which requires a non null module.

That is an implementation detail.

> I don't see any reason why we should accept null or why we should
> substitute 'null' with a (randomly picked?) module, especially
> since this looks like a pretty unusual corner case which can be
> easily worked around (in this case) when the behavior of the method
> in the presence of a null caller is known.

I see this as a basic hole in the whole notion of "current module". 
Surely if there is no module available then we should be in the 
unnamed-module?

Cheers,
David

> best regards,
>
> -- daniel
>