8333462: Performance regression of new DecimalFormat() when compare to jdk11

[lingjun-cg]

Run the below benchmark test ,it show the average time of new DecimalFormat() increase 18% when compare to jdk 11.

the result with jdk 11:

Benchmark                          Mode  Cnt    Score   Error  Units
JmhDecimalFormat.testNewOnly       avgt   50  248.300 ? 5.158  ns/op

the result with current jdk:

Benchmark                          Mode  Cnt    Score   Error  Units
JmhDecimalFormat.testNewOnly       avgt   50  303.381 ? 5.252  ns/op

@BenchmarkMode(Mode.AverageTime)
@Warmup(iterations = 5, time = 500, timeUnit = TimeUnit.MILLISECONDS)
@Measurement(iterations = 10, time = 500, timeUnit = TimeUnit.MILLISECONDS)
@State(Scope.Thread)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
public class JmhDecimalFormat {

    @Setup(Level.Trial)
    public void setup() {
    }

    @Benchmark
    public void testNewOnly() throws InterruptedException {
        new DecimalFormat("#0.00000");
    }
}

Compare the flame graph it shows the java.text.DecimalFormatSymbols#findNonFormatChar takes a significant time.
After replacing the lambda implementation with a simple loop , it shows nearly the same performance as jdk 11.

Benchmark                          Mode  Cnt    Score   Error  Units
JmhDecimalFormat.testNewOnly       avgt   50  209.874 ? 9.951  ns/op

flame-graph-jdk11-jdk21.zip

---

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Issue

• JDK-8333462: Performance regression of new DecimalFormat() when compare to jdk11 (Bug - P4)

Reviewers

• Chen Liang (@liach - Author) ⚠️ Review applies to a230ce00
• Naoto Sato (@naotoj - Reviewer) ⚠️ Review applies to a230ce00
• Justin Lu (@justin-curtis-lu - Committer) ⚠️ Review applies to a230ce00

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[openjdk]

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

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8333462: Performance regression of new DecimalFormat() when compare to jdk11

Reviewed-by: liach, naoto, jlu

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At the time when this comment was updated there had been 20 new commits pushed to the master branch:

• 67b9a08: 8333586: Improve syntax of @see tags in javax.lang.model
• 244f6ac: 8307824: Clean up Finalizable.java and finalize terminology in vmTestbase/nsk/share
• a706e35: 8332039: Cannot invoke "com.sun.source.util.DocTreePath.getTreePath()" because "path" is null
• 612b689: 8043226: Better diagnostics for non-applicable type annotations
• dce9703: 8333226: Regressions 2-3% in Compress ZGC after 8331253
• b101dcb: 8333312: Incorrect since tags on new ClassReader and ConstantPool methods
• e0bab78: 8326951: since-checker - missing @ since tags
• 31f7039: 8316131: runtime/cds/appcds/TestParallelGCWithCDS.java fails with JNI error
• 4a1cdd5: 8333486: Parallel: Remove unused methods in psParallelCompact
• 664c993: 8331731: ubsan: relocInfo.cpp:155:30: runtime error: applying non-zero offset to null pointer
• ... and 10 more: https://git.openjdk.org/jdk/compare/d230b30353f59135287436b09949b80e9fd73a93...master

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[mlbridge]

Webrevs

• 01: Full - Incremental (d5b9ccfb)
• 00: Full (a230ce00)

[naotoj]

LGTM

[justin-curtis-lu]

LGTM. Also needs copyright year update

[bchristi-git]

Would it be better if the benchmark returned the created DecimalFormat ?
Just thinking about dead code elimination:
https://github.com/openjdk/jmh/blob/master/jmh-samples/src/main/java/org/openjdk/jmh/samples/JMHSample_08_DeadCode.java

[lingjun-cg]

/integrate

[openjdk]

@lingjun-cg
Your change (at version d5b9ccf) is now ready to be sponsored by a Committer.

[D-D-H]

/sponsor

[openjdk]

Going to push as commit d826127.
Since your change was applied there have been 20 commits pushed to the master branch:

• 67b9a08: 8333586: Improve syntax of @see tags in javax.lang.model
• 244f6ac: 8307824: Clean up Finalizable.java and finalize terminology in vmTestbase/nsk/share
• a706e35: 8332039: Cannot invoke "com.sun.source.util.DocTreePath.getTreePath()" because "path" is null
• 612b689: 8043226: Better diagnostics for non-applicable type annotations
• dce9703: 8333226: Regressions 2-3% in Compress ZGC after 8331253
• b101dcb: 8333312: Incorrect since tags on new ClassReader and ConstantPool methods
• e0bab78: 8326951: since-checker - missing @ since tags
• 31f7039: 8316131: runtime/cds/appcds/TestParallelGCWithCDS.java fails with JNI error
• 4a1cdd5: 8333486: Parallel: Remove unused methods in psParallelCompact
• 664c993: 8331731: ubsan: relocInfo.cpp:155:30: runtime error: applying non-zero offset to null pointer
• ... and 10 more: https://git.openjdk.org/jdk/compare/d230b30353f59135287436b09949b80e9fd73a93...master

Your commit was automatically rebased without conflicts.

[openjdk]

@D-D-H @lingjun-cg Pushed as commit d826127.

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