JDK-8134691 : CommandLineFlagConstraint::AtParse is not useful and not what we need
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: runtime
  • Affected Version: 9
  • Priority: P2
  • Status: Resolved
  • Resolution: Withdrawn
  • Submitted: 2015-08-28
  • Updated: 2016-03-17
  • Resolved: 2016-03-17
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.

To download the current JDK release, click here.
JDK 10
10Resolved
Related Reports
Relates :  
JDK-8136421 - Integration
Relates :  
JDK-8130459 - Add additional validation after heap creation
Relates :  
JDK-8078556 - Runtime: implement ranges (optionally constraints) for those flags that have them missing
Description
JDK-8130459 added CommandLineFlagConstraint::AtParse, but it's not quite what we need.

AtParse denotes that a flag be checked for range/constraint ONLY at parse time, ie. only when the user sets the flag explicitly on command line. It was added to port over the existing runtime flag, but they need to be defined as AfterErgo type, so they get checked during the VM init process.

Therefore we can safely get rid of AtParse and with some small tweaks get the correct behavior.
Comments
Now that JEP-243 (JDK-8136421) makes the use of AtParse to ensure that EnableJVMCI is ON if any of the JMCI flags is being attempted to used (clever usage), the cat is out of the bag, and I'm not sure it's worthwhile fixing this and finding another clean mechanism for achieving this behavior. Therefore I am withdrawing this enhancement.
17-03-2016