8274276: Cache normalizedBase URL in URLClassPath.FileLoader

[stsypanov]

Currently on each invocation of URLClassPath.FileLoader.getResource() normalizedBase URL is recalculated using same final baseURL from parent class. This can be avoided giving significant improvement in memory consumption. Consider the benchmark:

@State(Scope.Benchmark)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Fork(jvmArgsAppend = {"-Xms2g", "-Xmx2g"})
public class URLClassPathBenchmark {
    private final ClassLoader classLoader = getClass().getClassLoader();

    @Benchmark
    public URL getResource() {
        return classLoader.getResource("file:./config/application.properties");
    }
}

it demonstrates improvement brought in by this patch:

before
Benchmark                                                           Mode  Cnt     Score     Error   Units
URLClassPathBenchmark.getResource                                   avgt   50  2840,746 ±  22,206   ns/op
URLClassPathBenchmark.getResource:·gc.alloc.rate                    avgt   50   645,313 ±   8,072  MB/sec
URLClassPathBenchmark.getResource:·gc.alloc.rate.norm               avgt   50  2403,258 ±  17,639    B/op
URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space           avgt   50   656,624 ± 116,090  MB/sec
URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space.norm      avgt   50  2450,175 ± 440,011    B/op
URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space       avgt   50     0,123 ±   0,149  MB/sec
URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space.norm  avgt   50     0,459 ±   0,556    B/op
URLClassPathBenchmark.getResource:·gc.count                         avgt   50    67,000            counts
URLClassPathBenchmark.getResource:·gc.time                          avgt   50   117,000                ms

after
Benchmark                                                           Mode  Cnt     Score    Error   Units
URLClassPathBenchmark.getResource                                   avgt  100  2596,719 ±  9,786   ns/op
URLClassPathBenchmark.getResource:·gc.alloc.rate                    avgt  100   448,780 ±  1,684  MB/sec
URLClassPathBenchmark.getResource:·gc.alloc.rate.norm               avgt  100  1528,040 ±  0,005    B/op
URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space           avgt  100   479,905 ± 23,369  MB/sec
URLClassPathBenchmark.getResource:·gc.churn.G1_Eden_Space.norm      avgt  100  1634,314 ± 79,821    B/op
URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space       avgt  100     0,101 ±  0,097  MB/sec
URLClassPathBenchmark.getResource:·gc.churn.G1_Survivor_Space.norm  avgt  100     0,345 ±  0,329    B/op
URLClassPathBenchmark.getResource:·gc.count                         avgt  100    98,000           counts
URLClassPathBenchmark.getResource:·gc.time                          avgt  100   218,000               ms

---

Progress

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Issue

• JDK-8274276: Cache normalizedBase URL in URLClassPath.FileLoader

Reviewers

• Daniel Fuchs (@dfuch - Reviewer)

Reviewing

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[bridgekeeper]

👋 Welcome back stsypanov! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

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[mlbridge]

Webrevs

• 01: Full - Incremental (937e6aee)
• 00: Full (dffc3301)

[dfuch]

This is calling an overidable method within a constructor, which might have unforeseen side effects. Can you make Loader::getBaseURL final? That would remove the concern.

[stsypanov]

@dfuch Sure, done!

[dfuch]

OK - LGTM. I have run tier1 and tier2 on your changes in our CI and nothing unexpected came up.

[openjdk]

⚠️ @stsypanov the full name on your profile does not match the author name in this pull requests' HEAD commit. If this pull request gets integrated then the author name from this pull requests' HEAD commit will be used for the resulting commit. If you wish to push a new commit with a different author name, then please run the following commands in a local repository of your personal fork:

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[openjdk]

@stsypanov 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:

8274276: Cache normalizedBase URL in URLClassPath.FileLoader

Reviewed-by: dfuchs

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 32 new commits pushed to the master branch:

• 0865120: 8274345: make build-test-lib is broken
• 75404ea: 8267636: Bump minimum boot jdk to JDK 17
• 14100d5: 8274170: Add hooks for custom makefiles to augment jtreg test execution
• daaa47e: 8274311: Make build.tools.jigsaw.GenGraphs more configurable
• 2cffe4c: 8274326: [macos] Ensure initialisation of sun/lwawt/macosx/CAccessibility in JavaComponentAccessibility.m
• 172900d: 8274255: Update javac messages to use "enum class" rather than "enum type"
• b0983df: 8274074: SIGFPE with C2 compiled code with -XX:+StressGCM
• 7436a77: 8274317: Unnecessary reentrant synchronized block in java.awt.Cursor
• 7426fd4: 8274325: C4819 warning at vm_version_x86.cpp on Windows after JDK-8234160
• e3aff8f: 8274289: jdk/jfr/api/consumer/TestRecordedFrameType.java failed with "RuntimeException: assertNotEquals: expected Interpreted to not equal Interpreted"
• ... and 22 more: https://git.openjdk.java.net/jdk/compare/971aa353aae51222ca33ebfdd61b91672a6c871a...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.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change. Possible candidates are the reviewers of this PR (@dfuch) but any other Committer may sponsor as well.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[stsypanov]

/integrate

[openjdk]

@stsypanov
Your change (at version 937e6ae) is now ready to be sponsored by a Committer.

[dfuch]

/sponsor

[openjdk]

Going to push as commit 94f5e80.
Since your change was applied there have been 45 commits pushed to the master branch:

• b36881f: 8274383: JNI call of getAccessibleSelection on a wrong thread
• be40373: 8274381: missing CAccessibility definitions in JNI code
• 79865cd: 8274259: G1: assert(check_alignment(result)) failed: address not aligned: 0x00000008baadbabe after JDK-8270009
• 961dcff: 8273581: Change the mechanism by which JDK loads the platform-specific FontManager class
• 6a573b8: 8273508: Support archived heap objects in SerialGC
• 3eca9c3: 8264707: HotSpot Style Guide should permit use of lambda
• af50772: 8231640: (prop) Canonical property storage
• ddc2627: 8273790: Potential cyclic dependencies between Gregorian and CalendarSystem
• 633eab2: 8174819: java/nio/file/WatchService/LotsOfEvents.java fails intermittently
• 8876eae: 8269685: Optimize HeapHprofBinWriter implementation
• ... and 35 more: https://git.openjdk.java.net/jdk/compare/971aa353aae51222ca33ebfdd61b91672a6c871a...master

Your commit was automatically rebased without conflicts.

[openjdk]

@dfuch @stsypanov Pushed as commit 94f5e80.

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