January 2021 - core-libs-dev

RFR: 8259816: Typo in java.util.stream package description
by Stuart Marks 27 Jan '21

27 Jan '21

Fix a typo, and change an example to use Stream.toList(). ------------- Commit messages: - 8259816: Typo in java.util.stream package description Changes: https://git.openjdk.java.net/jdk/pull/2249/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2249&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8259816 Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod Patch: https://git.openjdk.java.net/jdk/pull/2249.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/2249/head:pull/2249 PR: https://git.openjdk.java.net/jdk/pull/2249

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RFR: 8257074 Update the ByteBuffers micro benchmark
by Chris Hegarty 27 Jan '21

27 Jan '21

The ByteBuffers micro benchmark seems to be a little dated. It should be a useful resource to leverage when analysing the performance impact of any potential implementation changes in the byte buffer classes. More specifically, the impact of such changes on the performance of sharp memory access operations. This issue proposes to update the benchmark in the following ways to meet the aforementioned use-case: 1. Remove allocation from the individual benchmarks - it just creates noise. 2. Consolidate per-thread shared heap and direct buffers. 3. All scenarios now use absolute memory access operations - so no state of the shared buffers is considered. 4. Provide more reasonable default fork, warmup, etc, out-of-the-box. 5. There seems to have been an existing bug in the test where the size parameter was not always considered - this is now fixed. ------------- Commit messages: - Initial changes Changes: https://git.openjdk.java.net/jdk/pull/1430/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1430&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8257074 Stats: 69 lines in 1 file changed: 22 ins; 14 del; 33 mod Patch: https://git.openjdk.java.net/jdk/pull/1430.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/1430/head:pull/1430 PR: https://git.openjdk.java.net/jdk/pull/1430

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RFR: 8252842: Extend jmap to support parallel heap dump
by Lin Zang 27 Jan '21

27 Jan '21

8252842: Extend jmap to support parallel heap dump ------------- Commit messages: - fix white space trailing issue - 8252842: Extend jmap to support parallel heap dump Changes: https://git.openjdk.java.net/jdk/pull/2261/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2261&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8252842 Stats: 777 lines in 6 files changed: 590 ins; 57 del; 130 mod Patch: https://git.openjdk.java.net/jdk/pull/2261.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/2261/head:pull/2261 PR: https://git.openjdk.java.net/jdk/pull/2261

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RFR: 8260391: Remove StringCoding::err
by Claes Redestad 26 Jan '21

26 Jan '21

This patch removes the unused StringCoding::err method, and the associated native code. ------------- Commit messages: - Remove StringCoding::err Changes: https://git.openjdk.java.net/jdk/pull/2236/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2236&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8260391 Stats: 82 lines in 2 files changed: 0 ins; 82 del; 0 mod Patch: https://git.openjdk.java.net/jdk/pull/2236.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/2236/head:pull/2236 PR: https://git.openjdk.java.net/jdk/pull/2236

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RFR: 8260406: Do not copy pure java source code to gensrc
by Magnus Ihse Bursie 26 Jan '21

26 Jan '21

For java.base gensrc we do the following: # Copy two Java files that need no preprocessing. $(SUPPORT_OUTPUTDIR)/gensrc/java.base/java/lang/%.java: $(CHARACTERDATA_TEMPLATES)/%.java.template $(call LogInfo, Generating $(@F)) $(call install-file) GENSRC_CHARACTERDATA += $(SUPPORT_OUTPUTDIR)/gensrc/java.base/java/lang/CharacterDataUndefined.java \ $(SUPPORT_OUTPUTDIR)/gensrc/java.base/java/lang/CharacterDataPrivateUse.java What this means is that we have two "template" files that are just compiled as java files, but only after being copied to gensrc. :-) We should just rename these files to java and move them to the normal source directory. ------------- Commit messages: - 8260406: Do not copy pure java source code to gensrc Changes: https://git.openjdk.java.net/jdk/pull/2233/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2233&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8260406 Stats: 9 lines in 3 files changed: 0 ins; 8 del; 1 mod Patch: https://git.openjdk.java.net/jdk/pull/2233.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/2233/head:pull/2233 PR: https://git.openjdk.java.net/jdk/pull/2233

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RFR: 8242456: PreviewFeature.Feature enum removal of TEXT_BLOCKS
by Jan Lahoda 26 Jan '21

26 Jan '21

The enum constant is unused, and can be removed. The class is not an API. ------------- Commit messages: - 8242456: PreviewFeature.Feature enum removal of TEXT_BLOCKS Changes: https://git.openjdk.java.net/jdk/pull/2218/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2218&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8242456 Stats: 7 lines in 1 file changed: 0 ins; 7 del; 0 mod Patch: https://git.openjdk.java.net/jdk/pull/2218.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/2218/head:pull/2218 PR: https://git.openjdk.java.net/jdk/pull/2218

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Does "strictfp" affect called/intrinsified Math functions?
by Andrew Leonard 25 Jan '21

25 Jan '21

Hi, Can I just check my understanding is correct, in that the following example will not actually return a "strictfp" value, because the Math.exp() is not strictfp and by default is a non-strictfp Intrinsic inline implementation? Thanks Andrew private strictfp double strictfpMathExp(double input) { return Math.exp(input); }

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RFR: 8260329: Update references to TAOCP to latest edition
by Joe Darcy 25 Jan '21

25 Jan '21

Updating and regularizing several references to Knuth's The Art of Computer Programming. ------------- Commit messages: - 8260329 Changes: https://git.openjdk.java.net/jdk/pull/2215/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2215&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8260329 Stats: 11 lines in 2 files changed: 1 ins; 0 del; 10 mod Patch: https://git.openjdk.java.net/jdk/pull/2215.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/2215/head:pull/2215 PR: https://git.openjdk.java.net/jdk/pull/2215

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[11u] RFR: 7146776: deadlock between URLStreamHandler.getHostAddress and file.Handler.openconnection
by Doerr, Martin 25 Jan '21

25 Jan '21

Hi, JDK-7146776 is backported to 11.0.11-oracle. I'd like to backport it for parity. Change doesn't apply cleanly because of Copyright year changes and a minor difference in a hunk which gets removed by this change: 11u Code contains host.equals(""), patch wants to remove host.isEmpty() from URLStreamHandler.java. Bug: https://bugs.openjdk.java.net/browse/JDK-7146776 Original change: https://git.openjdk.java.net/jdk/commit/db9c114d 11u backport: http://cr.openjdk.java.net/~mdoerr/7146776_windows_deadlock_11u/webrev.00/ Please review. Best regards, Martin

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RFR: JDK-8260273: DataOutputStream writeChars optimization
by Hamlin Li 25 Jan '21

25 Jan '21

this is minor optimization following JDK-8254078. based on my tests with jmh, it has better performance when apply following patch: diff --git a/src/java.base/share/classes/java/io/DataOutputStream.java b/src/java.base/share/classes/java/io/DataOutputStream.java index 9a9a687403c..4ea497fc7c0 100644 --- a/src/java.base/share/classes/java/io/DataOutputStream.java +++ b/src/java.base/share/classes/java/io/DataOutputStream.java @@ -300,8 +300,9 @@ public class DataOutputStream extends FilterOutputStream implements DataOutput { int len = s.length(); for (int i = 0 ; i < len ; i++) { int v = s.charAt(i); - out.write((v >>> 8) & 0xFF); - out.write((v >>> 0) & 0xFF); + writeBuffer[0] = (byte)(v >>> 8); + writeBuffer[1] = (byte)(v >>> 0); + out.write(writeBuffer, 0, 2); } incCount(len * 2); } Basically, it has better performance when apply above patch: // without writeChars optimization patch, (-XX:-UseBiasedLocking) Benchmark (basicType) (size) Mode Cnt Score Error Units DataOutputStreamTest.dataOutputStreamOverBufferedFileStream STRING 4096 avgt 6 115.208 ± 0.327 us/op DataOutputStreamTest.dataOutputStreamOverByteArray STRING 4096 avgt 6 276.795 ± 0.449 us/op DataOutputStreamTest.dataOutputStreamOverRawFileStream STRING 4096 avgt 6 12356.969 ± 22.427 us/op // with writeChars optimization patch, (-XX:-UseBiasedLocking) Benchmark (basicType) (size) Mode Cnt Score Error Units DataOutputStreamTest.dataOutputStreamOverBufferedFileStream STRING 4096 avgt 6 133.706 ± 0.274 us/op DataOutputStreamTest.dataOutputStreamOverByteArray STRING 4096 avgt 6 130.979 ± 0.155 us/op DataOutputStreamTest.dataOutputStreamOverRawFileStream STRING 4096 avgt 6 6814.272 ± 52.770 us/op // without writeChars optimization patch, (-XX:+UseBiasedLocking) Benchmark (basicType) (size) Mode Cnt Score Error Units DataOutputStreamTest.dataOutputStreamOverBufferedFileStream STRING 4096 avgt 6 130.367 ± 8.759 us/op DataOutputStreamTest.dataOutputStreamOverByteArray STRING 4096 avgt 6 37.559 ± 0.059 us/op DataOutputStreamTest.dataOutputStreamOverRawFileStream STRING 4096 avgt 6 12385.030 ± 376.560 us/op // with writeChars optimization patch, (-XX:+UseBiasedLocking) Benchmark (basicType) (size) Mode Cnt Score Error Units DataOutputStreamTest.dataOutputStreamOverBufferedFileStream STRING 4096 avgt 6 45.494 ± 7.018 us/op DataOutputStreamTest.dataOutputStreamOverByteArray STRING 4096 avgt 6 33.015 ± 0.349 us/op DataOutputStreamTest.dataOutputStreamOverRawFileStream STRING 4096 avgt 6 6845.549 ± 38.712 us/op ------------- Commit messages: - JDK-8260273: DataOutputStream writeChars optimization Changes: https://git.openjdk.java.net/jdk/pull/2190/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2190&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8260273 Stats: 4 lines in 2 files changed: 1 ins; 0 del; 3 mod Patch: https://git.openjdk.java.net/jdk/pull/2190.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/2190/head:pull/2190 PR: https://git.openjdk.java.net/jdk/pull/2190

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