RFR: 8215159: Improve initial setup of system Properties

[Claes Redestad]

On 2018-12-11 18:41, Mandy Chung wrote:
> 
> 
> On 12/10/18 1:17 PM, Claes Redestad wrote:
>> Hi,
>>
>> by inverting the order in which the internal property maps are created,
>> we avoid some classloading and get a slightly more efficient code
>> execution profile in System.initPhase1.
>>
>> Webrev: http://cr.openjdk.java.net/~redestad/8215159/jdk.00/
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8215159
>>
> 
> This change looks okay to me.

Thanks!

> 
> ModuleBootstrap also removes some `jdk.module.*` private system 
> properties during
> module system initialization but they are only set if module-related 
> command-line
> options are set.   These properties are not present in the common 
> cases.   These
> private system properties are the interface between VM and libraries.   
> There is
> other mechanism that we can look into to replace using system properties 
> in the
> future.

Right, as we've discussed a bit off-list there are further improvements
that could be made.  For one we'd probably be better off without the
internal VM.savedProps map altogether, but usage has snuck into some
weird places.  Something for another day. :-)

/Claes

> 
> Mandy