RFR 8185496: Improve performance of system properties initialization in initPhase1 (original) (raw)

Mandy Chung mandy.chung at oracle.com
Fri Nov 9 17:15:55 UTC 2018

On 11/9/18 7:25 AM, Roger Riggs wrote:

Hi Mandy

On 11/08/2018 04:55 PM, Mandy Chung wrote: On 11/8/18 7:41 AM, Roger Riggs wrote:

Webrev updated in place:  (Only System.java is modified) http://cr.openjdk.java.net/%7Erriggs/webrev-props-cleanup-8185496/index.html Just notice this... I wonder if System.setProperties(null) should call VM.saveAndRemoveProperties(props) to be consistent.  It's an existing issue.  You may consider refactoring and adding initSystemProperties method that will be called from initPhase1 and setProperties. The purpose of VM.savedProperties is to ensure that the initial properties are not mutable. The AndRemove is an adhoc way to hide some properties that don't need to be seen by applications. Allowing the former set to be changed by setProperties() would break that intention. I'm not aware of any problems with the current implementation of (setProperties) and so would leave it alone at least for now. Further, System.setProperties() should be deprecated (probably for removal) since it gives the impression of being able to reset all the properties. But many property values are only used for initialization and are read or cached on first use and not read again because changing them has no effect or can cause unexpected behaviors.

I agree we should not do more on System.setProperties.   Your patch is good to go.

I also support to deprecate System::setProperties while we should collect some data and understand how it is used in existing libraries.

Mandy

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