RFR 8217660: Refactor module related locked_create_entry_or_null() functions

[Lois Foltan]

On 1/23/2019 4:28 PM, Harold Seigel wrote:
>  * Adds a PackageEntryTable::locked_create_entry() function for callers
>    who know the package entry cannot already exist.
>  * Replaces ModuleEntryTable::locked_create_entry_or_null() with
>    locked_create_entry().
>  * Adds a call to lookup_only(module_symbol) to check if a moduleEntry
>    exists, instead of depending on locked_create_entry_or_null()
>    returning null.
>
> Open Webrev: 
> http://cr.openjdk.java.net/~hseigel/bug_8217660/webrev/index.html

Hi Harold,

I think this looks good.  A couple of minor comments:

- can you add a comment before the definition of 
ModuleEntryTable::locked_create_entry() that indicates that it is the 
caller's responsibility to check if the module has already been defined 
prior to calling locked_create_entry().
- the only situation I see this as an issue is in create_javabase() but 
that method should only be called once during bootstrapping. There are 
no checks in ModuleEntry::set_javabase_ModuleEntry that ensures 
ModuleEntry::_javabase_module == NULL before setting.

I don't need to see another webrev.
Thanks,
Lois