September 2021 - core-libs-dev

RFR: 8269373: some tests in jdk/tools/launcher/ fails on localized Windows platform
by Masanori Yano 08 Sep '21

08 Sep '21

Hi all, Could you please review the 8269373 bug fixes? These tests call java.lang.ProcessBuilder in direct, so not used jtreg command option. To run non-localized tests, -Duser.language=en and -Duser.country=US options should be added in ProcessBuilder. ------------- Commit messages: - 8269373: some tests in jdk/tools/launcher/ fails on localized Windows platform Changes: https://git.openjdk.java.net/jdk/pull/4594/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4594&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8269373 Stats: 14 lines in 6 files changed: 5 ins; 0 del; 9 mod Patch: https://git.openjdk.java.net/jdk/pull/4594.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/4594/head:pull/4594 PR: https://git.openjdk.java.net/jdk/pull/4594

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RFR: 8273000: Remove WeakReference-based class initialisation barrier implementation
by Vladimir Ivanov 08 Sep '21

08 Sep '21

Get rid of WeakReference-based logic in DirectMethodHandle::checkInitialized() and reimplement it with `Unsafe::ensureClassInitialized()`/`shouldBeInitialized()`. The key observation is that `Unsafe::ensureClassInitialized()` does not block the initializing thread. Also, removed `Unsafe::shouldBeInitialized()` in `DMH::shouldBeInitialized(MemberName)` to save on calling into the VM. `Unsafe::ensureClassInitialized()` already has a fast-path check which checks whether the class is fully initialized or not. Testing: tier1 - tier6 ------------- Commit messages: - Remove WeakReference-based logic Changes: https://git.openjdk.java.net/jdk/pull/5258/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5258&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8273000 Stats: 35 lines in 1 file changed: 0 ins; 32 del; 3 mod Patch: https://git.openjdk.java.net/jdk/pull/5258.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/5258/head:pull/5258 PR: https://git.openjdk.java.net/jdk/pull/5258

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RFR: JDK-8273246 Amend the test java/nio/channels/DatagramChannel/ManySourcesAndTargets.java to execute in othervm mode
by Mark Sheppard 07 Sep '21

07 Sep '21

A number of nio DatagramChannel tests are intermittently failing on macosx-aarch64. In some instances this is a receive call blocking indefinitely waiting on data which has already been sent, and should be available immediately to the receive method call. Other test failure scenarios are problems during the test compilation phase with a SocketException being thrown and the message: "test result: Error. Agent communication error: java.net.SocketException: No buffer space available; check console log for any additional details" The ManySourcesAndTargets and other tests execute in agentvm mode. This results in certain test diagnostic Output being lost during the test failure handling capture process. To mitigate this lost diagnostics, the ManySourcesAndTargets test has been amended to execute in othervm mode. Additionally, to assist in the buffer allocation issue, the netstat command executed by the test failure_handler has an extra argument added to obtain additional details on mbuf usage. The failure handler will now execute with netstat -mm ------------- Commit messages: - JDK-8273246 Amend the test java/nio/channels/DatagramChannel/ManySourcesAndTargets.java to execute in othervm mode Changes: https://git.openjdk.java.net/jdk/pull/5366/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5366&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8273246 Stats: 3 lines in 2 files changed: 0 ins; 0 del; 3 mod Patch: https://git.openjdk.java.net/jdk/pull/5366.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/5366/head:pull/5366 PR: https://git.openjdk.java.net/jdk/pull/5366

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Suspicious duplicate condition in java.util.regex.Grapheme#isExcludedSpacingMark
by Andrey Turbanov 07 Sep '21

07 Sep '21

Hello. I found suspicious condition in the method java.util.regex.Grapheme#isExcludedSpacingMark It's detected by IntelliJ IDEA inspection 'Condition is covered by further condition' https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java… ``` private static boolean isExcludedSpacingMark(int cp) { return cp == 0x102B || cp == 0x102C || cp == 0x1038 || cp >= 0x1062 && cp <= 0x1064 || cp >= 0x1062 && cp <= 0x106D || // <== here is the warning cp == 0x1083 || cp >= 0x1087 && cp <= 0x108C || cp == 0x108F || cp >= 0x109A && cp <= 0x109C || cp == 0x1A61 || cp == 0x1A63 || cp == 0x1A64 || cp == 0xAA7B || cp == 0xAA7D; } ``` There are 2 sub-conditions in this complex condition: cp >= 0x1062 && cp <= 0x1064 || cp >= 0x1062 && cp <= 0x106D || The second condition is _wider_ than the first one. I believe it's a bug. The second condition (according to https://www.compart.com/en/unicode/category/Mc) should look like this: cp >= 0x1067 && cp <= 0x106D || 0x1065, 0x1066 are not from the Spacing_Mark category. Andrey Turbanov

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Re: RFR: JDK-8272192 Shortcut String equality checks by checking equality of the value array [v2]
by David Holmes 06 Sep '21

06 Sep '21

On Mon, 6 Sep 2021 06:41:38 GMT, q2q-2q2 <github.com+44376158+q2q-2q2(a)openjdk.org> wrote: >> src/java.base/share/classes/java/lang/String.java line 1964: >> >>> 1962: public boolean equalsIgnoreCase(String anotherString) { >>> 1963: if (anotherString != null) { >>> 1964: return false; >> >> This one is definitely wrong. > > Thank you So that begs the question as to what testing you did for this change? ------------- PR: https://git.openjdk.java.net/jdk/pull/5370

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Possible ClassCastException in java.util.regex.Pattern.BmpCharPredicate#union(java.util.regex.Pattern.CharPredicate...)
by Andrey Turbanov 04 Sep '21

04 Sep '21

Hello. I found suspicious code in the method "java.util.regex.Pattern.BmpCharPredicate#union(java.util.regex.Pattern.CharPredicate...)" https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java… static CharPredicate union(CharPredicate... predicates) { CharPredicate cp = ch -> { for (CharPredicate p : predicates) { if (!p.is(ch)) return false; } return true; }; for (CharPredicate p : predicates) { if (! (p instanceof BmpCharPredicate)) return cp; } return (BmpCharPredicate)cp; } Variable `cp` has type CharPredicate initially. And then it's casted to BmpCharPredicate. This cast always fails with ClassCastException when reached. Can reproduced in small sample class: public static void main(String[] args) { CharPredicate result = BmpCharPredicate.union(); System.out.println(result); } interface CharPredicate { boolean is(int ch); } interface BmpCharPredicate extends CharPredicate { static CharPredicate union(CharPredicate... predicates) { CharPredicate cp = ch -> true; for (CharPredicate p : predicates) { if (! (p instanceof BmpCharPredicate)) return cp; } return (BmpCharPredicate)cp; } } Exception in thread "main" java.lang.ClassCastException: class org.RegexpBug$BmpCharPredicate$$Lambda$14/0x0000000800c028f0 cannot be cast to class org.RegexpBug$BmpCharPredicate (org.RegexpBug$BmpCharPredicate$$Lambda$14/0x0000000800c028f0 and org.RegexpBug$BmpCharPredicate are in unnamed module of loader 'app') at org.RegexpBug$BmpCharPredicate.union(RegexpBug.java:20) at org.RegexpBug.main(RegexpBug.java:5) As I can see this method is never used. Perhaps it should be removed? Andrey Turbanov

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RFR: 8214761: Bug in parallel Kahan summation implementation
by Ian Graves 03 Sep '21

03 Sep '21

8214761: Bug in parallel Kahan summation implementation ------------- Commit messages: - 8214761: Bug in parallel Kahan summation implementation Changes: https://git.openjdk.java.net/jdk/pull/4674/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4674&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8214761 Stats: 18 lines in 3 files changed: 11 ins; 0 del; 7 mod Patch: https://git.openjdk.java.net/jdk/pull/4674.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/4674/head:pull/4674 PR: https://git.openjdk.java.net/jdk/pull/4674

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RFR: 8273250: Address javadoc issues in Deflater::setDictionationary
by Lance Andersen 02 Sep '21

02 Sep '21

Hi, Please review this trivial fix to the javadoc which addresses an issue shown via Intellij where the error: "Symbol 'getAdler' is inaccessible from here" is generated for the "@See Inflater#getAlder" references. Best Lance ------------- Commit messages: - Address JDK-8273250 Changes: https://git.openjdk.java.net/jdk/pull/5340/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5340&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8273250 Stats: 4 lines in 1 file changed: 0 ins; 0 del; 4 mod Patch: https://git.openjdk.java.net/jdk/pull/5340.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/5340/head:pull/5340 PR: https://git.openjdk.java.net/jdk/pull/5340

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RFR: JDK-8273229: Update OS detection code to recognize Windows Server 2022
by Matthias Baesken 02 Sep '21

02 Sep '21

Hello, please review this small change. The OS detection code of the JDK/JVM should recognize the new Windows server 2022 : https://docs.microsoft.com/en-us/lifecycle/products/windows-server-2022 https://docs.microsoft.com/en-us/windows-server/get-started/windows-server-… The build number of Windows server 2022 according to the documentation in the second link is 20348 . Thanks, Matthias ------------- Commit messages: - JDK-8273229 Changes: https://git.openjdk.java.net/jdk/pull/5347/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5347&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8273229 Stats: 11 lines in 2 files changed: 8 ins; 0 del; 3 mod Patch: https://git.openjdk.java.net/jdk/pull/5347.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/5347/head:pull/5347 PR: https://git.openjdk.java.net/jdk/pull/5347

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RFR: 8273140: Replace usages of Enum.class.getEnumConstants() with Enum.values() where possible
by Сергей Цыпанов 02 Sep '21

02 Sep '21

Just a very tiny clean-up. There are some places in JDK code base where we call `Enum.class.getEnumConstants()` to get all the values of the referenced `enum`. This is excessive, less-readable and slower than just calling `Enum.values()` as in `getEnumConstants()` we have volatile access: public T[] getEnumConstants() { T[] values = getEnumConstantsShared(); return (values != null) ? values.clone() : null; } private transient volatile T[] enumConstants; T[] getEnumConstantsShared() { T[] constants = enumConstants; if (constants == null) { /* ... */ } return constants; } Calling values() method is slightly faster: @BenchmarkMode(Mode.AverageTime) @OutputTimeUnit(TimeUnit.NANOSECONDS) @Fork(jvmArgsAppend = {"-Xms2g", "-Xmx2g"}) public class EnumBenchmark { @Benchmark public Enum[] values() { return Enum.values(); } @Benchmark public Enum[] getEnumConstants() { return Enum.class.getEnumConstants(); } private enum Enum { A, B } } Benchmark Mode Cnt Score Error Units EnumBenchmark.getEnumConstants avgt 15 6,265 ± 0,051 ns/op EnumBenchmark.getEnumConstants:·gc.alloc.rate avgt 15 2434,075 ± 19,568 MB/sec EnumBenchmark.getEnumConstants:·gc.alloc.rate.norm avgt 15 24,002 ± 0,001 B/op EnumBenchmark.getEnumConstants:·gc.churn.G1_Eden_Space avgt 15 2433,709 ± 70,216 MB/sec EnumBenchmark.getEnumConstants:·gc.churn.G1_Eden_Space.norm avgt 15 23,998 ± 0,659 B/op EnumBenchmark.getEnumConstants:·gc.churn.G1_Survivor_Space avgt 15 0,009 ± 0,003 MB/sec EnumBenchmark.getEnumConstants:·gc.churn.G1_Survivor_Space.norm avgt 15 ≈ 10⁻⁴ B/op EnumBenchmark.getEnumConstants:·gc.count avgt 15 210,000 counts EnumBenchmark.getEnumConstants:·gc.time avgt 15 119,000 ms EnumBenchmark.values avgt 15 4,164 ± 0,134 ns/op EnumBenchmark.values:·gc.alloc.rate avgt 15 3665,341 ± 120,721 MB/sec EnumBenchmark.values:·gc.alloc.rate.norm avgt 15 24,002 ± 0,001 B/op EnumBenchmark.values:·gc.churn.G1_Eden_Space avgt 15 3660,512 ± 137,250 MB/sec EnumBenchmark.values:·gc.churn.G1_Eden_Space.norm avgt 15 23,972 ± 0,529 B/op EnumBenchmark.values:·gc.churn.G1_Survivor_Space avgt 15 0,017 ± 0,003 MB/sec EnumBenchmark.values:·gc.churn.G1_Survivor_Space.norm avgt 15 ≈ 10⁻⁴ B/op EnumBenchmark.values:·gc.count avgt 15 262,000 counts EnumBenchmark.values:·gc.time avgt 15 155,000 ms ------------- Commit messages: - 8273140: Replace usages of Enum.class.getEnumConstants() with Enum.values() where possible Changes: https://git.openjdk.java.net/jdk/pull/5303/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5303&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8273140 Stats: 13 lines in 4 files changed: 0 ins; 2 del; 11 mod Patch: https://git.openjdk.java.net/jdk/pull/5303.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/5303/head:pull/5303 PR: https://git.openjdk.java.net/jdk/pull/5303

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