Review request: exports runtime support + jdk modules converted to use exports

[Mandy Chung]

  On 6/9/11 11:32 AM, Mandy Chung wrote:
>  On 6/9/11 5:48 AM, Alan Bateman wrote:
>> I've been looking at the webrev and was wondering about this. I 
>> grabbed the patch file from the webrev and did some tests and it 
>> looks like the stored configuration for simple tests jumps very 
>> significantly, like from about 6.5MB to 90MB. The reason is that java 
>> -m spends several seconds loading it. Are you seeing this too? 
>
> I can reproduce this.  My test cases require jdk.base and thus I 
> didn't see this.  The current default is "requires jdk" if no jdk 
> module is specified in the module-info that causes all jdk modules 
> (contexts and their local/remote maps) be included in the 
> configuration. I am looking into an optimization to this.
>
An update on the analysis:

I instrumented the simple library. This single context's name itself
takes up 80% of the config file size (~75M).

+jdk.boot+sun.charsets+sun.compat+sun.corba+sun.desktop+sun.ext+sun.instrument+sun.jaas+sun.jaxp+sun.jdbc+sun.jndi+sun.jsse+sun.jta+sun.kerberos+sun.localedata+sun.logging+sun.management+sun.resources+sun.rmi+sun.security.acl+sun.sunec

count  per-string bytes total bytes
327099     235          76868265

Each context contains a map from a remote class name to a context's name.
When the map's key is changed from package name to a class name, the
number of context's name is thus significantly increased.  A simple
fix would be using an integer as the context ID and storing the name
only once.

Top 15 strings with the highest total of bytes in the config file:
count   bytes    total  contexts name
327099    235 76868265   41     +jdk.boot+sun.charsets+sun.compat+sun.corba+sun.desktop+sun.ext+sun.instrument+sun.jaas+sun.jaxp+sun.jdbc+sun.jndi+sun.jsse+sun.jta+sun.kerberos+sun.localedata+sun.logging+sun.management+sun.resources+sun.rmi+sun.security.acl+sun.sunec
   5550     16    88800    1     sun.desktop at 7-ea
   4121     10    41210   11     +jdk.javac
   3722     10    37220    6     +sun.jaxws
   3467     13    45071    1     jdk.boot at 7-ea
   3325     14    46550    1     jdk.tools at 7-ea
   2502     13    32526    1     sun.jaxp at 7-ea
   2405     14    33670    1     sun.jaxws at 7-ea
   1677     14    23478    1     sun.corba at 7-ea
   1441     20    28820    1     jdk.tools.jaxws at 7-ea
    801     13    10413    9     +jdk.compiler
    768     14    10752    1     jdk.javac at 7-ea
    558     19    10602    1     sun.management at 7-ea

Total number of strings in the config file is 729694 but 26185
unique strings. Total bytes occupied by these strings is 91839030.

The strings created in the configuration includes
    context's name
    module's name at version
    module library path
    class name

There is other opportunity for optimization.  For example, for each class
from jdk.boot, there are 40 copies in the config as one in each remote map
of each context and there are 40 contexts requiring it.

Mandy