[GR-62002] [Native Image] `System.getProperties` evaluates all Lazy expensive values

[radcortez]

Describe the Issue

In Quarkus, to populate certain pieces of the configuration, we need to look up the available names in multiple sources (System, ENV, etc.).

The only way to retrieve the list of names coming from System properties is by calling System.getProperties(), and then either iterate the keys or call .propertyNames, stringPropertyNames.

Unfortunately, this means that we always have to pay the price of the expensive computation of the lazy values implemented in the substitution here: https://github.com/oracle/graal/blob/master/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/SystemPropertiesSupport.java#L209-L212

We do measure a 5-6 ms startup time in our environments, which we would like to avoid since we don't need the values at all, and just the available names set by System properties. We did workaround the issue by adding a substitution in the entire Properties returned by System, but this is far from ideal: quarkusio/quarkus#45997

I'm happy to work and submit a PR with an agreement on what the solution could be.

Using the latest version of GraalVM can resolve many issues.

• I tried with the latest version of GraalVM.

GraalVM Version

java 21.0.5 2024-10-15 LTS
Java(TM) SE Runtime Environment Oracle GraalVM 21.0.5+9.1 (build 21.0.5+9-LTS-jvmci-23.1-b48)
Java HotSpot(TM) 64-Bit Server VM Oracle GraalVM 21.0.5+9.1 (build 21.0.5+9-LTS-jvmci-23.1-b48, mixed mode, sharing)

Operating System and Version

Darwin Kernel Version 23.6.0: Mon Jul 29 21:13:00 PDT 2024; root:xnu-10063.141.2~1/RELEASE_X86_64 x86_64

Troubleshooting Confirmation

• I tried the suggestions in the troubleshooting guide.

Run Command

NA

Expected Behavior

Have a way to call System.getProperties and the list of names without incurring the penalty cost of evaluating the lazy values.

Actual Behavior

NA

Steps to Reproduce

NA

Additional Context

No response

Run-Time Log Output and Error Messages

No response

[selhagani]

Hi radcortez,
Thank you for reaching out to us about this!
Could you please try using the latest available GraalVM version to test this issue? You can find it here: https://github.com/graalvm/graalvm-ce-builds/releases/
Please do let us know if you are still facing this issue even after updating.

[radcortez]

Yes, it also happens in the latest version. If you notice, the main code is initializing all the System properties:

https://github.com/oracle/graal/blob/master/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/SystemPropertiesSupport.java#L209-L212

This method is used as a Substitution for System.getProperties:
https://github.com/oracle/graal/blob/master/substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jdk/JavaLangSubstitutions.java#L386-L389

[selhagani]

We will take a closer look into this and I'll make sure to keep you updated. Thank you.

[radcortez]

Thanks!

[christianhaeubl]

@radcortez : is the difference still measurable now that #10613 was merged?

[radcortez]

I'll try, but I believe so by looking into the code:

Getting the Properties still forces initialization:
https://github.com/oracle/graal/pull/10613/files#diff-80640936382dc53cb941f0a1a422242a09d01fbd7cfa0ac55ea988ceca1b40e8R208-R211

And the substitution:
https://github.com/oracle/graal/pull/10613/files#diff-422e3fa386126a69506423650c878a251e18cc6e6cfdb39d87923a88a97628a3R389

[christianhaeubl]

Thanks!

Yes, getting the Properties still forces the initialization. However, for correctness reasons, we had to convert a few of the lazy initializations to eager initializations. So, it is possible that there is no longer a measurable difference.