Review Request JDK-8136930 Examine implications for custom launchers, equivalent of java -X options in particular

David Holmes david.holmes at oracle.com
Thu Jun 9 06:44:34 UTC 2016


Hi Mandy,

On 9/06/2016 10:45 AM, Mandy Chung wrote:
> Adding jigsaw-dev where the code review is posted.  See [1] for Coleen’s review comment.
>
>> On Jun 8, 2016, at 4:53 PM, David Holmes <david.holmes at oracle.com> wrote:
>>
>> On 9/06/2016 8:37 AM, Coleen Phillimore wrote:
>>>
>>>
>>> I have to ask why Hotspot convention was violated with this new option
>>> syntax?  These options don't start with -X and the values aren't
>>> specified as : separators like the rest? Like
>>> -Xshare:{dump,auto,on,off}, etc.  Why are these different?
>> Good question. Presumably these are not non-standard arguments, but common arguments that must always be supported, hence not -X. But this somewhat muddies the waters as the VM itself has, to my recollection, never had standard arguments: VM arguments are -XX arguments, other arguments were launcher arguments. So yes this seems to be introducing a new kind of VM argument.
>>
>
> -agentlib, -agentpath, -javaagent, -verbose:{gc,class,jni} are neither -X nor -XX options.

Mea culpa - yes we already have these kind of options. Thanks.

>> This also begs the questions as to where you get help for these options once moved into the JVM? Will the launcher be updated to pretend they are launcher arguments and document them?
>
> Good question on the documentation.  java -help continues to print these module options as -verbose:gc option is shown and I don’t see any issue for java help message and its documentation to list VM options.

Ok.

> I think they should be listed in the HotSpot VM options documentation:
>   http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html

Note that documentation currently states:

"Standard options recognized by the Java HotSpot VM are described on the 
Java Application Launcher reference pages for Windows and Solaris & 
Linux. This document deals exclusively with non-standard options 
recognized by the Java HotSpot VM."

but I tend to agree that it should also list all options that are not 
launcher options. There should also be a cross-reference from the JNI 
invocation API documentation to whereever these options are documented.

Thanks,
David
-----

> Mandy
> [1] http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2016-June/019882.html
>


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