Proposed enhancement to Layer API

David M. Lloyd david.lloyd at
Wed Jan 4 14:33:57 UTC 2017

On 01/04/2017 08:26 AM, Alan Bateman wrote:
> On 04/01/2017 14:21, David M. Lloyd wrote:
>> We need the ability to add content to a module after it is defined to
>> support our existing deployment architecture.  Is there a material
>> problem with having this feature, other than transgressing your sense
>> of "should"?
> Can you expand a bit on this? If you are generating modules at run-time,
> maybe generating module-info.class files or via the Builder API, then I
> would expect that you at least know what packages are in the module and
> which packages are exported unconditionally. It sounds a bit strange to
> create a module without knowing anything about its contents (assuming
> that is what this is about).

In some cases we have the full contents, but in other cases we allow 
dynamic deployment contents to be updated or added at run time (mostly 
for development purposes but it can be practical and useful to add 
contents at run time as well in certain cases).  Because of the way that 
our linkage algorithm is designed, our current Jigsaw integration 
prototype just adds all contents after the fact (mainly because of the 
dependency chain involved in building our modules, in which the contents 
simply aren't available at the time we establish the class loader and 

It is theoretically possible to rewrite our linkage algorithm to use the 
first known set of packages as the static package set for a module, but 
we'd still need the ability to add contents anyway, or else drop the 
feature entirely, which would be unfortunate.


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