JDK-8311285: report some fontconfig related environment variables in hs_err file

[MBaesken]

There are a number of important environment variables influencing how fontconfig works.
See for example
https://man.archlinux.org/man/fonts-conf.5
Some of them should be added to the list of reported environment variables in hs_err file because e.g. a bad setting for some of them can even lead sometimes to crashes.

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Issue

• JDK-8311285: report some fontconfig related environment variables in hs_err file (Bug - P4)

Reviewers

• Christoph Langer (@RealCLanger - Reviewer) ⚠️ Review applies to 76583497
• Thomas Stuefe (@tstuefe - Reviewer) ⚠️ Review applies to 76583497

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[mlbridge]

Webrevs

• 01: Full - Incremental (4d19b2d7)
• 00: Full (76583497)

[dholmes-ora]

The XDG values are not specifically fontconfig related.

[dholmes-ora]

This seems a very limited selection - why only these three? (And I find it hard to imagine how these particular ones might lead to crashes - FONTCONFIG_USE_MMAP seems much more interesting in that regard).

[MBaesken]

Hi David , FONTCONFIG_USE_MMAP sounds interesting, I saw this too in the list of environment variables. Should I add this one?

And I find it hard to imagine how these particular ones might lead to crashes

Shared cache home directory (in a shared HOME shared between different hosts) was causing a lot of trouble and leading to crashes rather often in our AIX tests. So this one is interesting for sure.

[dholmes-ora]

Hi David , FONTCONFIG_USE_MMAP sounds interesting, I saw this too in the list of environment variables. Should I add this one?

It seems more useful, at first glance, than the others :)

I find it hard to know where to draw the line here. Over time you could end up eventually adding everything. Would it be better to dump the entire environment to a file along-side the hs_err file?

[MBaesken]

Hi David,

Would it be better to dump the entire environment to a file along-side the hs_err file?

I am fine with this idea.
However I am not sure if this is the policy of the OpenJDK. If you print everything, maybe some application dependent variables show up as well that have nothing to do with the JVM at all. For example in my environment on my Windows laptop, there would be environment variables about OneDrive and about Perforce SCM, not sure if we want to print those.

[dholmes-ora]

Yes I guess dumping the whole environment is a bit too extreme. As it is we have to be cautious about what external information we capture in the hs_err log.

[RealCLanger]

This looks like useful additions, I'd also vote for adding FONTCONFIG_USE_MMAP.

[openjdk]

@MBaesken This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8311285: report some fontconfig related environment variables in hs_err file

Reviewed-by: clanger, stuefe

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 27 new commits pushed to the master branch:

• 92ca670: 8310170: Use sp's argument to improve performance of outputStream::indent and remove SP_USE_TABS
• 25cbe85: 8310550: Adjust references to rt.jar
• 848abd2: 8311511: Improve description of NativeLibrary JFR event
• 6485b7d: 6875229: Wrong placement of icons in JTabbedPane in Nimbus
• 27de536: 8311581: Remove obsolete code and comments in TestLVT.java
• e848d94: 8310923: Refactor Currency tests to use JUnit
• 0c86c31: 8302351: "assert(!JavaThread::current()->is_interp_only_mode() || !nm->method()->is_continuation_enter_intrinsic() || ContinuationEntry::is_interpreted_call(return_pc)) failed: interp_only_mode but not in enterSpecial interpreted entry" in fixup_callers_callsite
• ec7da91: 8240567: MethodTooLargeException thrown while creating a jlink image
• 97e99f0: 8311087: PhiNode::wait_for_region_igvn should break early
• 7173c30: 8307766: Linux: Provide the option to override the timer slack
• ... and 17 more: https://git.openjdk.org/jdk/compare/711cddd899048236bbc3c0aa7e4ac0fc8aebe4d2...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[tstuefe]

LGTM, modulo David's advice (remove the comment, add FONTCONFIG_USE_MMAP).

Cheers, Thomas

[MBaesken]

Hi Thomas and Christoph, thanks for the reviews !
I removed the comment, added FONTCONFIG_USE_MMAP.

/integrate

[openjdk]

Going to push as commit 0ef03f1.
Since your change was applied there have been 27 commits pushed to the master branch:

• 92ca670: 8310170: Use sp's argument to improve performance of outputStream::indent and remove SP_USE_TABS
• 25cbe85: 8310550: Adjust references to rt.jar
• 848abd2: 8311511: Improve description of NativeLibrary JFR event
• 6485b7d: 6875229: Wrong placement of icons in JTabbedPane in Nimbus
• 27de536: 8311581: Remove obsolete code and comments in TestLVT.java
• e848d94: 8310923: Refactor Currency tests to use JUnit
• 0c86c31: 8302351: "assert(!JavaThread::current()->is_interp_only_mode() || !nm->method()->is_continuation_enter_intrinsic() || ContinuationEntry::is_interpreted_call(return_pc)) failed: interp_only_mode but not in enterSpecial interpreted entry" in fixup_callers_callsite
• ec7da91: 8240567: MethodTooLargeException thrown while creating a jlink image
• 97e99f0: 8311087: PhiNode::wait_for_region_igvn should break early
• 7173c30: 8307766: Linux: Provide the option to override the timer slack
• ... and 17 more: https://git.openjdk.org/jdk/compare/711cddd899048236bbc3c0aa7e4ac0fc8aebe4d2...master

Your commit was automatically rebased without conflicts.

[openjdk]

@MBaesken Pushed as commit 0ef03f1.

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