RFR JDK-8066709 Make some JDK system properties read only

[David Holmes]

Hi Roger,

On 5/06/2018 5:55 AM, Roger Riggs wrote:
> Hi Lance,
> 
> On 6/4/2018 12:09 PM, Lance Andersen wrote:
>> Hi Roger,
>>
>> Overall, it looks very good.
>>
>> A couple of quick thoughts, nothing that needs any action unless you 
>> feel the desire :-)
>>
>> Line 671 in System.java, it mentions ‘standard’ system properties. 
>>  (as does the existing Implementation note) but it does not really 
>> specify what a standard system property is (though it can be assumed) 
>> in getProperties overview.  Not a big deal, just thought I would point 
>> it out in case you had a alternative thought.
> Yes, it is a bit vague and the documentation of properties is spread 
> over many packages and classes.
> 'Standard' generally refers to any property defined in the scope of Java 
> SE or the documented JDK properties.
> (For example, those subject to the CSR process).

The "standard properties" are those documented in the table in 
System.getProperties() following

"This set of system properties always includes values for the following 
keys:"

and which is followed shortly after by:

"In addition to the standard system properties, the system properties 
may include the following keys:"

These are the properties that must be provided by all implementations of 
the Java platform.

David
-----

>>
>> Do you think we should had a mention in getProperty() about this 
>> cached properties (or do we think the reference to getProperties() is 
>> enough)
> Hard to say,  there will be a release note, but the properties methods 
> are well known and it is
> likely no one reads the javadoc anymore.  getProperty delegates to 
> getProperties for most of its behavior.
> 
> Adding a repeat of the API note to System.setProperties and 
> System.setProperty might be more to the point,
> warning against setting standard system properties via the API.
> I added the apinote to each of the 6 methods for setting, clearing, or 
> getting properties. If that seems excessive,
> I'm open to removing it from those that provide the least value.
> 
> Thanks, Roger
> 
>>
>> Best
>> Lance
>>> On Jun 4, 2018, at 9:32 AM, Roger Riggs <Roger.Riggs at oracle.com 
>>> <mailto:Roger.Riggs at oracle.com>> 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/ 
>>> <http://cr.openjdk.java.net/%7Erriggs/webrev-static-property-8066709/>
>>>
>>> Issue:
>>> https://bugs.openjdk.java.net/browse/JDK-8066709
>>>
>>> CSR:
>>> https://bugs.openjdk.java.net/browse/JDK-8204235
>>>
>>> Thanks, Roger
>>>
>>>
>>
>> <http://oracle.com/us/design/oracle-email-sig-198324.gif>
>> <http://oracle.com/us/design/oracle-email-sig-198324.gif><http://oracle.com/us/design/oracle-email-sig-198324.gif> 
>>
>> <http://oracle.com/us/design/oracle-email-sig-198324.gif>Lance 
>> Andersen| Principal Member of Technical Staff | +1.781.442.2037
>> Oracle Java Engineering
>> 1 Network Drive
>> Burlington, MA 01803
>> Lance.Andersen at oracle.com <mailto:Lance.Andersen at oracle.com>
>>
>>
>>
>