Jigsaw classpath mode support

[Alan Bateman]

On 15/08/2012 23:04, Mandy Chung wrote:
> :
>
>> One thing that I can't tell from the changes is the value of the 
>> sun.boot.module.classpath property. That might be clear once Karen 
>> publishes the hotspot changes. I ask because I can't tell if 
>> Package.SystemPackage.isPackageFromModule is right, meaning whether 
>> JVM_GetSystemPackage returns the value of sun.boot.module.classpath 
>> for packages in the system modules.
>>
> Yes, JVM_GetSystemPackage will return the value of 
> sun.boot.module.classpath for packages in the system modules.  It's a 
> simple way to tag a package in the system module.
Okay, that's what I thought (it caught my eye because I thought that 
JVM_GetSystemPackage was expected to return a specific path or filename 
rather than a classpath).


>
>> In Launcher. ExtClassLoader there is code to split the extension 
>> directory into the paths that come before and after the default 
>> location. I think I need help in understand why someof this is needed 
>> because if someone sets java.ext.dirs then it should be a complete 
>> override?
>>
>
> It's for searching native libraries from the module image or 
> user-specified ext dir.  The ExtClassLoader overrides the findLibrary 
> method.   The java.ext.dirs can be overridden in the command line; if 
> not set, the VM will set its value to the default ext dirs.  In 
> addition, someone can set java.ext.dirs to include JAVA_HOME/lib/ext 
> plus other additional directory.   If the default ext dir is inclued 
> in the java.ext.dirs, ExtClassLoader needs to locate the native 
> library from the module image and loads a native library from each 
> directory specified in the property value before and after the default.
Thanks, the bit I was missing here was the possibility that someone 
might run with java.ext.dirs set to include the legacy ext directory.

In that case, shouldn't the check on L220 be <= index so that the 
extensions directory ends up in prepaths rather than postpaths. That way 
it will search the legacy location before looking in the module directory.

-Alan.