February 2009 - core-libs-dev

Re: Strange speed dependency
by Martin Buchholz 03 Feb '09

03 Feb '09

Ulf, the new UTF_8 decoder in very recent jdks is much faster, and the primary trick that was used to achieve that was reducing the size of the bytecode in the hot methods and moving cold code to separate methods. Martin On Mon, Feb 2, 2009 at 14:35, Ulf Zibis <Ulf.Zibis(a)gmx.de> wrote: > Hi all, > > I have experienced a strange speed dependency of HotSpot compiled code after > little change in code, which is not part of the "hot" loop. > Is there any explanation for this behavior? > > Code before little change: > > class UTF_8_new extends Unicode { > > // .... > > private static CoderResult malformed(ByteBuffer src, int sp, > CharBuffer dst, int dp, int nb) { > src.position(sp -= nb - src.arrayOffset()); > CoderResult cr = malformedN(src, nb); > updatePositions(src, sp, dst, dp); > return cr; > } > > // .... > > while (sp < sl) { > // .... > int b2 = sa[sp++]; > int b3 = sa[sp++]; > int b4 = sa[sp++]; > if (isMalformed4(b1, b2)) > return malformed(src, sp-2, dst, dp, 2); > if (isNotContinuation(b3)) > return malformed(src, sp-1, dst, dp, 3); > if (isNotContinuation(b4)) > return malformed(src, sp, dst, dp, 4); > if (dp >= dl - 1) > return overflow(src, sp-4, dst, dp); > int uc = (b1 << 18) ^ (b2 << 12) ^ (b3 << 06) ^ b4 ^ > 0x00381f80; > // .... > } > > The above code has following output (note gain against UTF_8_70$Decoder): > time for sun.nio.cs.UTF_8_60$Decoder: 2701 ms > time for sun.nio.cs.UTF_8_70$Decoder: 1984 ms > time for sun.nio.cs.UTF_8_new$Decoder: 1720 ms // gain: 264 ms > time for sun.nio.cs.UTF_8_last$Decoder: 2110 ms > > > Following small code change made the "hot" part of the loop much slower: > > class UTF_8_new extends Unicode { > > // .... > > private static CoderResult malformed(ByteBuffer src, int sp, > CharBuffer dst, int dp, int nb) { > src.position(sp - src.arrayOffset()); // removed subtraction of > nb > CoderResult cr = malformedN(src, nb); > updatePositions(src, sp, dst, dp); > return cr; > } > > // .... > > while (sp < sl) { > // .... > int b2 = sa[sp++]; > int b3 = sa[sp++]; > int b4 = sa[sp++]; > if (isMalformed4(b1, b2)) > return malformed(src, sp-4, dst, dp, 2); > if (isNotContinuation(b3)) > return malformed(src, sp-4, dst, dp, 3); > if (isNotContinuation(b4)) > return malformed(src, sp-4, dst, dp, 4); > if (dp >= dl - 1) > return overflow(src, sp-4, dst, dp); > int uc = (b1 << 18) ^ (b2 << 12) ^ (b3 << 06) ^ b4 ^ > 0x00381f80; > // .... > } > > time for sun.nio.cs.UTF_8_60$Decoder: 2731 ms > time for sun.nio.cs.UTF_8_70$Decoder: 1981 ms > time for sun.nio.cs.UTF_8_new$Decoder: 1872 ms // gain: 109 ms > time for sun.nio.cs.UTF_8_last$Decoder: 2094 ms > > For complete sources compare following revisions (... and run > UTF_8Benchmark.java ): > https://java-nio-charset-enhanced.dev.java.net/source/browse/java-nio-chars… > https://java-nio-charset-enhanced.dev.java.net/source/browse/java-nio-chars… > > > -Ulf > > > >

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hg: jdk7/tl/jdk: 2 new changesets
by weijun.wang＠sun.com 03 Feb '09

03 Feb '09

Changeset: dbb82636df41 Author: weijun Date: 2009-02-03 09:38 +0800 URL: http://hg.openjdk.java.net/jdk7/tl/jdk/rev/dbb82636df41 6552334: Enable DNS in Kerberos by default Reviewed-by: valeriep ! src/share/classes/sun/security/krb5/Config.java ! src/share/classes/sun/security/krb5/KrbServiceLocator.java ! test/sun/security/krb5/DnsFallback.java Changeset: ca32af4c0ea5 Author: weijun Date: 2009-02-03 09:38 +0800 URL: http://hg.openjdk.java.net/jdk7/tl/jdk/rev/ca32af4c0ea5 6785456: Read Kerberos setting from Windows environment variables Reviewed-by: valeriep ! src/share/classes/sun/security/krb5/Config.java

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hg: jdk7/tl/jdk: 6791927: Wrong Locale in HttpCookie::expiryDate2DeltaSeconds
by jean-christophe.collet＠sun.com 02 Feb '09

02 Feb '09

Changeset: 6c5d04d1eff4 Author: jccollet Date: 2009-02-02 16:50 +0100 URL: http://hg.openjdk.java.net/jdk7/tl/jdk/rev/6c5d04d1eff4 6791927: Wrong Locale in HttpCookie::expiryDate2DeltaSeconds Summary: Force Locale.US when parsing the cookie expiration date. Reviewed-by: chegar ! src/share/classes/java/net/HttpCookie.java + test/java/net/CookieHandler/B6791927.java

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hg: jdk7/tl/langtools: 3 new changesets
by tim.bell＠sun.com 02 Feb '09

02 Feb '09

Changeset: d957ceba29f9 Author: xdono Date: 2009-01-29 13:21 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/langtools/rev/d957ceba29f9 Added tag jdk7-b45 for changeset 30db5e0aaf83 ! .hgtags Changeset: be546a6c08e3 Author: tbell Date: 2009-01-29 21:48 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/langtools/rev/be546a6c08e3 Merge Changeset: 49281ea88125 Author: tbell Date: 2009-01-30 23:28 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/langtools/rev/49281ea88125 Merge

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hg: jdk7/tl/jdk: 3 new changesets
by tim.bell＠sun.com 02 Feb '09

02 Feb '09

Changeset: 997c6403bf2e Author: xdono Date: 2009-01-29 13:21 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/jdk/rev/997c6403bf2e Added tag jdk7-b45 for changeset 527b426497a2 ! .hgtags Changeset: 2113813eda62 Author: tbell Date: 2009-01-29 21:46 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/jdk/rev/2113813eda62 Merge Changeset: f9cf49b7b248 Author: tbell Date: 2009-01-30 23:27 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/jdk/rev/f9cf49b7b248 Merge

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hg: jdk7/tl/jaxws: Added tag jdk7-b45 for changeset dea7753d7139
by tim.bell＠sun.com 02 Feb '09

02 Feb '09

Changeset: af4a3eeb7812 Author: xdono Date: 2009-01-29 13:21 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/jaxws/rev/af4a3eeb7812 Added tag jdk7-b45 for changeset dea7753d7139 ! .hgtags

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hg: jdk7/tl/jaxp: Added tag jdk7-b45 for changeset 0f113667880d
by tim.bell＠sun.com 02 Feb '09

02 Feb '09

Changeset: b2271877894a Author: xdono Date: 2009-01-29 13:21 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/jaxp/rev/b2271877894a Added tag jdk7-b45 for changeset 0f113667880d ! .hgtags

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hg: jdk7/tl/hotspot: Added tag jdk7-b45 for changeset 945bf7540697
by tim.bell＠sun.com 02 Feb '09

02 Feb '09

Changeset: 16bb38eeda35 Author: xdono Date: 2009-01-29 13:20 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/hotspot/rev/16bb38eeda35 Added tag jdk7-b45 for changeset 945bf7540697 ! .hgtags

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hg: jdk7/tl/corba: Added tag jdk7-b45 for changeset 68814aa5b44b
by tim.bell＠sun.com 02 Feb '09

02 Feb '09

Changeset: 1691dbfc08f8 Author: xdono Date: 2009-01-29 13:20 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/corba/rev/1691dbfc08f8 Added tag jdk7-b45 for changeset 68814aa5b44b ! .hgtags

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hg: jdk7/tl: Added tag jdk7-b45 for changeset 99846f001ca2
by tim.bell＠sun.com 02 Feb '09

02 Feb '09

Changeset: e8a2a4d18777 Author: xdono Date: 2009-01-29 13:20 -0800 URL: http://hg.openjdk.java.net/jdk7/tl/rev/e8a2a4d18777 Added tag jdk7-b45 for changeset 99846f001ca2 ! .hgtags

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