RFR JDK-8066709 Make some JDK system properties read only

[Alan Bateman]

On 04/06/2018 14:32, Roger Riggs wrote:
> Please review a change to make the values of java.home, user.home, 
> user.dir, and user.name
> effectively read-only for internal use.  The values are cached during 
> initialization and the
> cached values are used.
>
> Webrev:
> http://cr.openjdk.java.net/~rriggs/webrev-static-property-8066709/
>
> Issue:
>   https://bugs.openjdk.java.net/browse/JDK-8066709
>
> CSR:
>   https://bugs.openjdk.java.net/browse/JDK-8204235
Can the @apiNote be split up so that the list of 4 properties moves to 
an @implNote? Also "changing any standard property" may need 
clarification as it can mean both changing a system property in a 
running VM and also changing it by starting the VM with a value for one 
of these properties.

I think I agree with Max on finding another name for the internal class 
as it is a class to get the original value of a few critical properties. 
Also I think we need to look at other ways to do the initialization, 
maybe in conjunction with VM.saveAndRemoveProperties so that we are 
saving the initial values of properties in one place.

Are the changes to SocksSocketImpl correct? I may have missed something 
but the original called System.getProperty("user.dir") in a privileged 
block so I'm wondering if getUserNameChecked is needed.

The static USER_DIR can be dropped from WindowsFileSystemProvider as 
there is only one instance of the provider.

The other usages look okay to me.

-Alan