March 2020 - core-libs-dev

RFR: 8239365: ProcessBuilder/Basic.java test modifications for AIX execution
by Adam Farley8 22 Apr '20

22 Apr '20

Hi All, Reviews and sponsor requested for a small test change. Short version: When an AIX machine has the file set "bos.msg.en_US.rte", the error messages are not in a form that the test expects, causing failure. The simplest option appears to be adding the second potential form of the message into the regex (see webrev). http://cr.openjdk.java.net/~afarley/8239365.1/webrev/ Bug: https://bugs.openjdk.java.net/browse/JDK-8239365 Best Regards Adam Farley IBM Runtimes Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU

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Review Request: 8238358: Implementation of JEP 371: Hidden Classes
by Mandy Chung 18 Apr '20

18 Apr '20

Please review the implementation of JEP 371: Hidden Classes. The main changes are in core-libs and hotspot runtime area. Small changes are made in javac, VM compiler (intrinsification of Class::isHiddenClass), JFR, JDI, and jcmd. CSR [1]has been reviewed and is in the finalized state (see specdiff and javadoc below for reference). Webrev: http://cr.openjdk.java.net/~mchung/valhalla/webrevs/hidden-classes/webrev.03 Hidden class is created via `Lookup::defineHiddenClass`. From JVM's point of view, a hidden class is a normal class except the following: - A hidden class has no initiating class loader and is not registered in any dictionary. - A hidden class has a name containing an illegal character `Class::getName` returns `p.Foo/0x1234` whereas `GetClassSignature` returns "Lp/Foo.0x1234;". - A hidden class is not modifiable, i.e. cannot be redefined or retransformed. JVM TI IsModifableClass returns false on a hidden. - Final fields in a hidden class is "final". The value of final fields cannot be overriden via reflection. setAccessible(true) can still be called on reflected objects representing final fields in a hidden class and its access check will be suppressed but only have read-access (i.e. can do Field::getXXX but not setXXX). Brief summary of this patch: 1. A new Lookup::defineHiddenClass method is the API to create a hidden class. 2. A new Lookup.ClassOption enum class defines NESTMATE and STRONG option that can be specified when creating a hidden class. 3. A new Class::isHiddenClass method tests if a class is a hidden class. 4. Field::setXXX method will throw IAE on a final field of a hidden class regardless of the value of the accessible flag. 5. JVM_LookupDefineClass is the new JVM entry point for Lookup::defineClass and defineHiddenClass to create a class from the given bytes. 6. ClassLoaderData implementation is not changed. There is one primary CLD that holds the classes strongly referenced by its defining loader. There can be zero or more additional CLDs - one per weak class. 7. Nest host determination is updated per revised JVMS 5.4.4. Access control check no longer throws LinkageError but instead it will throw IAE with a clear message if a class fails to resolve/validate the nest host declared in NestHost/NestMembers attribute. 8. JFR, jcmd, JDI are updated to support hidden classes. 9. update javac LambdaToMethod as lambda proxy starts using nestmates and generate a bridge method to desuger a method reference to a protected method in its supertype in a different package This patch also updates StringConcatFactory, LambdaMetaFactory, and LambdaForms to use hidden classes. The webrev includes changes in nashorn to hidden class and I will update the webrev if JEP 372 removes it any time soon. We uncovered a bug in Lookup::defineClass spec throws LinkageError and intends to have the newly created class linked. However, the implementation in 14 does not link the class. A separate CSR [2] proposes to update the implementation to match the spec. This patch fixes the implementation. The spec update on JVM TI, JDI and Instrumentation will be done as a separate RFE [3]. This patch includes new tests for JVM TI and java.instrument that validates how the existing APIs work for hidden classes. javadoc/specdiff http://cr.openjdk.java.net/~mchung/valhalla/webrevs/hidden-classes/api/ http://cr.openjdk.java.net/~mchung/valhalla/webrevs/hidden-classes/specdiff/ JVMS 5.4.4 change: http://cr.openjdk.java.net/~mchung/valhalla/webrevs/hidden-classes/Draft-JV… CSR: https://bugs.openjdk.java.net/browse/JDK-8238359 Thanks Mandy [1] https://bugs.openjdk.java.net/browse/JDK-8238359 [2] https://bugs.openjdk.java.net/browse/JDK-8240338 [3] https://bugs.openjdk.java.net/browse/JDK-8230502

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RFR: 8241055: Regex Grapheme Matcher Performance Depends too much on Total Input Sequence Size
by Philipp Kunz 16 Apr '20

16 Apr '20

Hi, Any opinions on the attached patch or someone tempted to sponsor it? Regards, Philipp

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Re: jpackage and macOS Catalina notarization
by James Elliott 16 Apr '20

16 Apr '20

[Whoops, it seems that this list strips out image attachments, so my first attempt to send this message was pretty useless. Trying again, after uploading the screenshot to my web server so I can link to it instead.] Ok, thanks for clarifying that, I will drop my expectations for Catalina happiness for the moment, and perhaps can help make things work better when I have some time. Is there a pointer at how one gets vetted for submitting pull requests? Or I could just look at the source and post ideas here if that is better. For now, here is what a jpackage-created disk image looks like when I open it in Catalina: https://deepsymmetry.org/images/jpackage_dmg_screenshot.png The command that generates this is: https://github.com/Deep-Symmetry/beat-link-trigger/blob/master/.github/scri… <https://github.com/Deep-Symmetry/beat-link-trigger/blob/master/.github/scri…> There are no errors reported during the build Cheers, -James > Date: Wed, 15 Jan 2020 14:54:55 +0100 > From: Michael Paus <mp(a)jugs.org <mailto:mp@jugs.org>> > To: core-libs-dev(a)openjdk.java.net <mailto:core-libs-dev@openjdk.java.net> > Subject: Re: jpackage and macOS Catalina notarization > Message-ID: <84d90e7b-fbc8-4be5-09a2-56457edf4e23(a)jugs.org <mailto:84d90e7b-fbc8-4be5-09a2-56457edf4e23@jugs.org>> > Content-Type: text/plain; charset=utf-8; format=flowed > >> I also notice that the background image and Applications folder alias that are supposed to be in the disk image don?t seem to work in Catalina, so I may give up on having jpackage create my disk images as well, and do that using native tools, until that can be fixed. (I realize it is in early access still, and hope these issues are being worked on.) > > What exactly is wrong with the background image? Were there any build > errors reported during packaging? > > The creation of the disk image is done via some script and you can tell > jpackage via the > option --temp <some empty dir> to dump that into a temporary folder. You > can modify it > and place it into another folder which you tell jpackage via > --resource-dir <some dir with the modified script> > Maybe you can fix your issue that way or at least you can find out what > the problem is. > > I am still on the previous version of macOS until all these Catalina > issues are sorted out. > Java/JavaFX on Catalina is a mess right now.

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RFR: JDK-8237490: [macos] Add support notarizing jpackage app-image and dmg
by Andy Herrick 07 Apr '20

07 Apr '20

Please review the fix to issue [1] at [2]. This change enables notarization on Mac for dmg images and app-image zip files. /Andy [1]: https://bugs.openjdk.java.net/browse/JDK-8237490 [2]: http://cr.openjdk.java.net/~herrick/8237490

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[PATCH] Trivial improvement for j.l.Character.toString()
by Сергей Цыпанов 06 Apr '20

06 Apr '20

Hello, I think we can reduce allocation rate for j.l.Character.toString() by calling String.valueOf(char) instead of String.valueOf(char[]). Current implementation creates char[] with one char which is later decoded into byte[]. Instead String.valueOf(char) decodes char directly consuming less memory. I've used benchmark [1] and on my machine got those results (JDK 14): Benchmark Mode Score Error Units CharacterToStringBenchmark.toString_utf8 avgt 14.723 ± 1.354 ns/op CharacterToStringBenchmark.valueOf_utf8 avgt 7.678 ± 0.601 ns/op CharacterToStringBenchmark.toString_latin avgt 10.992 ± 1.371 ns/op CharacterToStringBenchmark.valueOf_latin avgt 7.844 ± 1.044 ns/op CharacterToStringBenchmark.toString_utf8:·gc.alloc.rate.norm avgt 96.003 ± 0.001 B/op CharacterToStringBenchmark.valueOf_utf8:·gc.alloc.rate.norm avgt 48.002 ± 0.001 B/op CharacterToStringBenchmark.toString_latin:·gc.alloc.rate.norm avgt 72.003 ± 0.001 B/op CharacterToStringBenchmark.valueOf_latin:·gc.alloc.rate.norm avgt 48.002 ± 0.001 B/op Patch is below. With best regards, Sergey Tsypanov [1] https://github.com/stsypanov/strings/blob/master/src/jmh/java/tsypanov/stri… diff --git a/src/java.base/share/classes/java/lang/Character.java b/src/java.base/share/classes/java/lang/Character.java --- a/src/java.base/share/classes/java/lang/Character.java +++ b/src/java.base/share/classes/java/lang/Character.java @@ -3285,7 +3285,7 @@ "SYMBOLS AND PICTOGRAPHS EXTENDED-A", "SYMBOLSANDPICTOGRAPHSEXTENDED-A"); - private static final int blockStarts[] = { + private static final int[] blockStarts = { 0x0000, // 0000..007F; Basic Latin 0x0080, // 0080..00FF; Latin-1 Supplement 0x0100, // 0100..017F; Latin Extended-A @@ -8068,7 +8068,7 @@ UNKNOWN, // E01F0..10FFFF }; - private static HashMap<String, Character.UnicodeScript> aliases; + private static final HashMap<String, Character.UnicodeScript> aliases; static { aliases = new HashMap<>((int)(153 / 0.75f + 1.0f)); aliases.put("ADLM", ADLAM); @@ -8421,8 +8421,7 @@ * @return a string representation of this object. */ public String toString() { - char buf[] = {value}; - return String.valueOf(buf); + return toString(value); } /**

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RFR 8015413 Reformat line in Class.privateGetPublicFields() to be more debugger-friendly
by Vipin Mv1 01 Apr '20

01 Apr '20

Hi All, Please find the below changes for the issue https://bugs.openjdk.java.net/browse/JDK-8015413 diff -r 53568400fec3 src/java.base/share/classes/java/lang/Class.java --- a/src/java.base/share/classes/java/lang/Class.java Thu Mar 26 15:26:51 2020 +0000 +++ b/src/java.base/share/classes/java/lang/Class.java Mon Mar 30 17:31:04 2020 +0530 @@ -3163,7 +3163,8 @@ ReflectionData<T> rd = reflectionData(); if (rd != null) { res = rd.publicFields; - if (res != null) return res; + if (res != null) + return res; } // Use a linked hash set to ensure order is preserved and Thanks & Regards Vipin MV

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RFR (S): 8241947: Minor comment fixes for system property handling
by Langer, Christoph 01 Apr '20

01 Apr '20

Hi, please review a small fix that updates two comments. The first one, in make/autoconf/spec.gmk.in, is probably quite old. It talks about handling of a property "vm.vendor" in VersionProps.java.template. However, there is no property "vm.vendor", it must rather be "java.vendor". I stumbled over that when looking at the change of JDK-4947890 (Minimize JNI upcalls in system-properties initialization). The second one is the code comment attached to "private static Properties props;" in java.lang.System. After JDK-8197927 (Allow the system property `java.vendor.version` to be undefined), "java.vendor.version" can be undefined, so this should be reflected in the comment. I also took the liberty to remove an unneeded import statement. Bug: https://bugs.openjdk.java.net/browse/JDK-8241947 Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8241947.0/ Thanks Christoph

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Re: RFR: 8238665: Add JFR event for direct memory statistics
by Denghui Dong 01 Apr '20

01 Apr '20

Hi Erik, Updated. Webrev: http://cr.openjdk.java.net/~ddong/8238665/webrev.01/ Thanks Denghui Dong ------------------------------------------------------------------ From:Erik Gahlin <erik.gahlin(a)oracle.com> Send Time:2020年3月5日(星期四) 06:33 To:董登辉(卓昂) <denghui.ddh(a)alibaba-inc.com> Cc:hotspot-jfr-dev <hotspot-jfr-dev(a)openjdk.java.net> Subject:Re: RFR: 8238665: Add JFR event for direct memory statistics Hi Denghui, Looking through you patch again. Could you add copyright headers, and change “5000 ms” to “5 s” in the .jfc files. When you reply with the updated patch, could you please include core-libs-dev(a)openjdk.java.net in the reply since you are modifying exports in java.base. Thanks Erik On 4 Mar 2020, at 20:35, Erik Gahlin <erik.gahlin(a)oracle.com> wrote: Hi Denghui, I have tested your fix and it seems to work. TestDefaultConfiguration takes into account the event is periodic, so it doesn't complain as I expected. Looks good. I can sponsor this. Thanks Erik On 3 Mar 2020, at 07:14, Denghui Dong <denghui.ddh(a)alibaba-inc.com> wrote: Hi Erik, I agree with you that the default interval should be changed to 5s, the webrev (http://cr.openjdk.java.net/~ddong/8238665/webrev.01/) has been updated. No need to modify TestDefaultConfigurations.java, it is passed. Testing (Linux release/slow debug build): jdk/jfr, all passed except TestNativeLibrariesEvent and TestNetworkUtilizationEvent(unstable). And these two test failures were not caused by this patch. And there were some test errors in slow debug build, I have checked the error test list and confirm they are also error in slow debug build without this patch, such as TestRecordedFrame. There are two new files in this patch, should I add copyright header to them? Thanks Denghui Dong ------------------------------------------------------------------ From:Erik Gahlin <erik.gahlin(a)oracle.com> Send Time:2020年3月3日(星期二) 04:08 To:董登辉(卓昂) <denghui.ddh(a)alibaba-inc.com> Cc:hotspot-jfr-dev <hotspot-jfr-dev(a)openjdk.java.net> Subject:Re: RFR: 8238665: Add JFR event for direct memory statistics Hi Denghui, Thanks for the explanation. I think the default interval could be increased to once every 5 seconds. Have you run the all the tests in test/jdk/jdk/jfr? I would expect TestDefaultConfigurations to have failed unless modified. Thanks Erik On 2020-02-26 14:40, 董登辉(卓昂) wrote: PING: Could you review it? Bug: https://bugs.openjdk.java.net/browse/JDK-8238665 Webrev: http://cr.openjdk.java.net/~ddong/8238665/webrev.01/ ------------------------------------------------------------------ From:董登辉(卓昂) <denghui.ddh(a)alibaba-inc.com> Send Time:2020年2月11日(星期二) 16:13 To:Erik Gahlin <erik.gahlin(a)oracle.com> Cc:hotspot-jfr-dev <hotspot-jfr-dev(a)openjdk.java.net> Subject:Re: RFR: 8238665: Add JFR event for direct memory statistics Hi Erik, Thanks for the review. See answers embedded. New webrev: http://cr.openjdk.java.net/~ddong/8238665/webrev.01/ On Feb 11, 2020, at 1:52 AM, Erik Gahlin <erik.gahlin(a)oracle.com> wrote: Hi Denghiu, Can you explain when this event can be useful, i.e. when troubleshooting x etc.? This makes it easier to determine if the event should be on by default, if it is worth the increased startup cost that the instrumentation creates and what a reasonable period for the event should be. Many Java middleware(e.g. Netty) and applications use direct memory for achieving higher performance, if java process use too much direct memory, some exceptions will occur, such as oom-killer. Hence, it’s necessary to monitor it, and we use JMX to monitor it in our production environment currently. src/jdk.jfr/share/classes/jdk/jfr/events/DirectMemoryStatisticsEvent.java: @Label("TotalCapacity") -> @Label("Total Capacity") @Label("MemoryUsed") -> @Label("Memory Used”) Updated What is meant by 'limit'? Could we have a better field name and/or description that explains what this fields contains, because it is not obvious from that name. Fields that contains bytes, should have the DataAmount; annotation. What is the value if -XX:MaxDirectMemorySize has not been set? limit -> maxCapacity if -XX:MaxDirectMemorySize has not been set, the value of Runtime.getRuntime().maxMemory() will be used. Can you make the event class final. Updated @StackTrace(false) should not be needed. Removed test/jdk/jdk/jfr/event/runtime/TestDirectMemoryStatisticsEvent.java: Use try-with-resources on the Recording object. Updated Thanks Denghui Dong Thanks Erik On 2020-02-07 06:24, Denghui Dong wrote: Hi, Could I have a review of a change that adds JFR event for direct memory statistics Bug: https://bugs.openjdk.java.net/browse/JDK-8238665 Webrev: http://cr.openjdk.java.net/~ddong/8238665/webrev.00/ Test: test/jdk/jdk/jfr/event/runtime/TestDirectMemoryStatisticsEvent.java Thanks Denghui Dong

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JDK 15 RF(pre)R of JDK-8241374: add Math.absExact
by Joe Darcy 01 Apr '20

01 Apr '20

Hello, Please review the initial proposed wording of the spec for JDK-8241374: add Math.absExact The eventual wording needs to be replicated four times (Math.absExact(int), Math.absExact(long), StrictMath.absExact(int), StrictMath.absExact(long)) so I want to get the wording agreed to before presenting it in quadruplicate. The other "exact" methods mention overflow so I wanted the spec to absExact to include both "exact" and "overflow" in its description. Tests will follow in subsequent review iterations. Thanks, -Joe diff -r c5d90e8d4a46 src/java.base/share/classes/java/lang/Math.java --- a/src/java.base/share/classes/java/lang/Math.java Sat Mar 28 11:00:09 2020 -0400 +++ b/src/java.base/share/classes/java/lang/Math.java Sat Mar 28 10:17:39 2020 -0700 @@ -1369,6 +1369,32 @@ } /** + * Returns the mathematical absolute value of an {@code int} value + * if it is exactly representable as an {@code int}, throwing + * {@code ArithmeticException} if the result overflows the + * positive {@code int} range. + * + * <p>Since the range of two's complement integers is asymmetric + * with one additional negative value, the mathematical absolute + * value of {@link Integer#MIN_VALUE} overflows the positive + * {@code int} range and an exception is thrown for that argument. + * + * @param a the argument whose absolute value is to be determined + * @return the absolute value of the argument absent overflow + * @throws ArithmeticException if the argument is {@link Integer#MIN_VALUE} + * @see Math#abs(int) + * @since 15 + */ + public static int absExact(int a) { + if (a == Integer.MIN_VALUE) + throw new ArithmeticException("Cannot represent " + + "absolute value of " + + "Integer.MIN_VALUE"); + else + return abs(a); + } + + /** * Returns the absolute value of a {@code long} value. * If the argument is not negative, the argument is returned. * If the argument is negative, the negation of the argument is returned.

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