A summary about JDK9 Features. (31/Jul/2015) This slide is used for Java Japan User Group LT with beer.

1. JDK9
KUBOTA Yuji (@sugarlife)
Java Japan User Group LT with b33r
10/Aug/2015

2. Attention
•Depends on OpenJDK project.
•This slide provides only the
summary for LT. Something
may have been changed until
General Availability is released.
•Drunken Speaker, Drunken LT.
Please, don’t be serious :p
http://openjdk.java.net/projects/jdk9/ (31/Jul/2015)

3. Who am I
•KUBOTA Yuji (@sugarlife)
•icedtea committer
(HeapStats)
•OpenJDK Contributor
•JavaOne Speaker
•Hard-hearing person

4. JDK9 Schedule
•2015/12/10: Feature Complete
• : Many tests
•2016/07/21: Final Release
Candidate
•2016/09/22: General Availability
http://openjdk.java.net/projects/jdk9/

5. What features will come?
102: Process API Updates
110: HTTP 2 Client
143: Improve Contended Locking
158: Unified JVM Logging
165: Compiler Control
193: Variable Handles
197: Segmented Code Cache
199: Smart Java Compilation, Phase Two
201: Modular Source Code
211: Elide Deprecation Warnings on Import Statements
212: Resolve Lint and Doclint Warnings
213: Milling Project Coin
214: Remove GC Combinations Deprecated in JDK 8
215: Tiered Attribution for javac
216: Process Import Statements Correctly
217: Annotations Pipeline 2.0
219: Datagram Transport Layer Security (DTLS)
220: Modular Run-Time Images
221: Simplified Doclet API
222: jshell: The Java Shell (Read-Eval-Print Loop)
223: New Version-String Scheme
224: HTML5 Javadoc
226: UTF-8 Property Files
227: Unicode 7.0
228: Add More Diagnostic Commands
229: Create PKCS12 Keystores by Default
230: Microbenchmark Suite
231: Remove Launch-Time JRE Version Selection
232: Improve Secure Application Performance
233: Generate Run-Time Compiler Tests Automatically
235: Test Class-File Attributes Generated by javac
236: Parser API for Nashorn
237: Linux/AArch64 Port
240: Remove the JVM TI hprof Agent
241: Remove the jhat Tool
243: Java-Level JVM Compiler Interface
244: TLS Application-Layer Protocol Negotiation Extension
245: Validate JVM Command-Line Flag Arguments
246: Leverage CPU Instructions for GHASH and RSA
247: Compile for Older Platform Versions
248: Make G1 the Default Garbage Collector
249: OCSP Stapling for TLS
250: Store Interned Strings in CDS Archives
251: Multi-Resolution Images
252: Use CLDR Locale Data by Default
253: Prepare JavaFX UI Controls & CSS APIs for Modularization
254: Compact Strings
255: Merge Selected Xerces 2.11.0 Updates into JAXP
256: BeanInfo Annotations
257: Update JavaFX/Media to Newer Version of GStreamer
258: HarfBuzz Font-Layout Engine

6. What features will come?
102: Process API Updates
110: HTTP 2 Client
143: Improve Contended Locking
158: Unified JVM Logging
165: Compiler Control
193: Variable Handles
197: Segmented Code Cache
199: Smart Java Compilation, Phase Two
201: Modular Source Code
211: Elide Deprecation Warnings on Import Statements
212: Resolve Lint and Doclint Warnings
213: Milling Project Coin
214: Remove GC Combinations Deprecated in JDK 8
215: Tiered Attribution for javac
216: Process Import Statements Correctly
217: Annotations Pipeline 2.0
219: Datagram Transport Layer Security (DTLS)
220: Modular Run-Time Images
221: Simplified Doclet API
222: jshell: The Java Shell (Read-Eval-Print Loop)
223: New Version-String Scheme
224: HTML5 Javadoc
226: UTF-8 Property Files
227: Unicode 7.0
228: Add More Diagnostic Commands
229: Create PKCS12 Keystores by Default
230: Microbenchmark Suite
231: Remove Launch-Time JRE Version Selection
232: Improve Secure Application Performance
233: Generate Run-Time Compiler Tests Automatically
235: Test Class-File Attributes Generated by javac
236: Parser API for Nashorn
237: Linux/AArch64 Port
240: Remove the JVM TI hprof Agent
241: Remove the jhat Tool
243: Java-Level JVM Compiler Interface
244: TLS Application-Layer Protocol Negotiation Extension
245: Validate JVM Command-Line Flag Arguments
246: Leverage CPU Instructions for GHASH and RSA
247: Compile for Older Platform Versions
248: Make G1 the Default Garbage Collector
249: OCSP Stapling for TLS
250: Store Interned Strings in CDS Archives
251: Multi-Resolution Images
252: Use CLDR Locale Data by Default
253: Prepare JavaFX UI Controls & CSS APIs for Modularization
254: Compact Strings
255: Merge Selected Xerces 2.11.0 Updates into JAXP
256: BeanInfo Annotations
257: Update JavaFX/Media to Newer Version of GStreamer
258: HarfBuzz Font-Layout Engine
( ﾟдﾟ )

7. Give it a once-over!
•This color’s feature is important
for ME who develop the product
depends on JVM.
•This color’s feature is
interesting for someone who
develop java applications.
•Good feature. But not affects on
me.

8. 102: Process API Updates
•Do you want information
about process? ok, here is.

9. 110: HTTP 2 Client
•Do you want API for
HTTP/2 ? ok, here is.

10. 143: Improve Contended Locking
•Good speed for contended
java object monitors.
•JVM will get a better
performance without change
of your codes.
•But, HeapStats (includes
thread monitor) developers
may be required hard work.

11. 158: Unified JVM Logging
•Shall we unify the log format of
JVM: e.g. compiler, gc,
classload, metaspace, etc...
•If you develop log parser, watch it.
•Xlog[:[<what>][:[<output>][:[<decorat
ors>][:<output-options>]]]]
•Xlog:gc=debug:file=gc.log:uptimemi
llis,pids:filecount=5,filesize=1024

12. 165: Compiler Control
•I WANNA CONTROL COMPILER
MORE DETAIL!
•You (probably JVM tester) can
•add some order when specified
method is being compiled (for c1
and c2).
• print assembly, set breakpoint,
enable compile or not, and more.
•change the option sets while run

13. 193: Variable Handles
•sun.misc.Unsafe may be removed.
•So we prepare the alternatives.
This JEP is the first step for it.

14. (おまけ) sun.misc.Unsafe 動向
• 6/15-16 に行われた JCP Executive Committee Meeting で隠蔽・削除
に向けた影響や代替方法などの話し合いが行われた
• 元々 sun.* 等は Jigsaw(module化) 関係で処遇を決める必要があった
• JCP Meeting の議題はここ、Unsafeに関する議事録はここ。
• この代替方法の最初のステップとして先の VarHandles が提案され、つ
い最近(7月)に JDK9 に盛り込まれることが決まった
• VarHandles Project 詳細 (JVM Language Summit 2014)
http://www.oracle.com/technetwork/java/jvmls2014sandoz-2265216.pdf
• 今のところは
• sun.misc.Unsafe などが deprecated / removed される時期は未明
• sun.misc.Unsafe を含む重要な内部 API はJDK9 では隠蔽のみ、JDK10 で
は削除したいという方向に議論が進んでいる (ソース：ML, JEP260)
• 代替方法も提案されているが実際に実装が揃うのはこれから
• という状況なので、JDK9 で使う方法を含めた具体的な実装はまだこれ
からですが、準備は意識した方が良いです。Feature Complete で確認
しましょう :) なお、黒魔術なので仕組みを理解してから使いましょう

15. 197: Segmented Code Cache
•Code cache diet.
•JVM will get a better
performance without change
of your codes.

16. 199: Smart Java Compilation, Phase
Two
•sjavac.

17. 201: Modular Source Code
•JDK source code into
modules.
•A part of Project Jigsaw.
•If you read OpenJDK source
code, you need to remake
your nautical table :p

18. 211: Elide Deprecation Warnings
on Import Statements
•Lint warnings is cry-wolf?
•javac always show warning
when you import statement
which include a deprecated
method or member.
•So resolve it.

19. 212: Resolve Lint and Doclint
Warnings
•To clean lint and doclint
errors of some JDK
components.

20. 213: Milling Project Coin
•Add language changes.
•@SafeVargs on private methods
• non-overridable executable.
•improve try-with-resource
• allow effectively final variables to
be used as resources.
•Allow diamond with anonymous
classes if the argument type of
the inferred type is denotable.
•and more two coins.

21. 214: Remove GC Combinations
Deprecated in JDK 8
•Good bye following GC Combi.
•DefNew + CMS
•ParNew + SerialOld
•DefNew + iCMS
•ParNew + iCMS
•CMS foreground(s)
• UseCMSCompactAtFullCollection
• CMSFullGCsBeforeCompaction
• UseCMSCollectionPassing

22. 215: Tiered Attribution for javac
•New type checking in javac.
•If you have interest in “type” in
compiler, you should read this
implementation.

23. 216: Process Import Statements
Correctly
•Fix javac.

24. 217: Annotations Pipeline 2.0
•javac again.

25. 219: Datagram Transport Layer
Security (DTLS)
•API for DTLS 1.0 (RFC 4347)
and DTLS 1.2 (RFC 6347)

26. 220: Modular Run-Time Images
•Restructure the JDK and JRE
to accommodate modules.
•A main part of Project Jigsaw
•Many risks and impacts
•no longer contain the files
• lib/rt.jar, lib/tools.jar, lib/dt.jar,..
•Class loader of some existing
packages will change, and more.
•But very useful for many Dev.

27. 221: Simplified Doclet API
•Replace Docklet API
(com.sun.javadoc) .

28. 222: jshell: The Java Shell (Read-
Eval-Print Loop)
•No need more Test.java!
•An interactive tool for Java
programming language.
•You can use it already at below.
•https://jdk9.java.net/download/
•@bitter_fox joined this project.
•(Japanese committer)

29. 223: New Version-String Scheme
•Change version-string format.
•Security update 2 times +
Minor update 1 times
•Current
• long: 1.8.0_20-b62
• short:8u20
•Proposed
• long: 9.1.2+62
• short:9.1.2
• $MAJOR.$MINOR.$SECURITY

30. 224: HTML5 Javadoc
http://www.w3.org/html/logo/

31. 226: UTF-8 Property Files
•You will be enable to use
UTF-8 property files.

32. 227: Unicode 7.0
•You will..( see title.

33. 228: Add More Diagnostic
Commands
•Add below commands
•print_class_summary (loaded classes)
•print_codegenlist (method queued)
•print_vm_state
•print_uft8pool
•datadump_request (heapdump?)
•dump_codelist (n-methods)
•print_codeblocks (code cache)
•set_vmflag

34. 229: Create PKCS12 Keystores
by Default
•Improve security.

35. 230: Microbenchmark Suite
•JMH++
•Add a basic suite of
microbenchmark to JDK codes.

36. 231: Remove Launch-Time JRE
Version Selection
•Remove forgotten options.
•“-version:” option
•Not “-version” option
•“JRE-Version” manifest entry
at jar file.

37. 232: Improve Secure Application
Performance
•Good speed with a security
manager installed.

38. 233: Generate Run-Time
Compiler Tests Automatically
•Generate jtreg-compatible
automatically for openjdk
developers.
•If you want to evaluate JVM
with new CPU instructions,
optimizations, and other
enhancements, generated
tests should be useful.

39. 235: Test Class-File Attributes
Generated by javac
•yes, javac.

40. 236: Parser API for Nashorn
•To get IDE support for
Nashorn.

41. 237: Linux/AArch64 Port
•ARM®

42. 240: Remove the JVM TI hprof
Agent
•Good bye hprof
•See also (alternatives)
•OProfile
•perf
•YourKit
•SystemTap (for debug)

43. 241: Remove the jhat Tool
•Good bye jhat
•See also (alternatives)
•Eclipse MAT

44. 243: Java-Level JVM Compiler
Interface
•You can trace JVM JIT
activity via this interface.

45. 244: TLS Application-Layer
Protocol Negotiation Extension
•javax.net.ssl package
supports the TLS ALPN.
•This feature relates to
HTTP/2 support (JEP110).

46. 245: Validate JVM Command-
Line Flag Arguments
•For example, some JVM flag
takes an out-of-range value,
and crashes without an
informative error message.
•So fix it.

47. 246: Leverage CPU Instructions
for GHASH and RSA
•Good security with a low
overhead.

48. 246: Leverage CPU Instructions
for GHASH and RSA
•Good security with a low
overhead.
• for SPARC and Intel x64 CPU.

49. 247: Compile for Older Platform
Versions
•javac for older.

50. 248: Make G1 the Default
Garbage Collector
•Oracle says “G1 is good”.
•Huge impact to a operation
by default JVM options.
•But I think that all listeners
set a configuration to use
specified GC. So this change
does not impact you.
•Really?

51. 249: OCSP Stapling for TLS
•TLS. Support RFC 6961.

52. 250: Store Interned Strings in
CDS Archives
•Interned String will be stored
in Class-Data Sharing when
G1GC used.
•A history of a housing
•Permanent Gen (JDK6)
•Java Heap (JDK7-8)
•Class-Data Sharing (JDK9+G1)

53. 251: Multi-Resolution Images
•A new java.awt.image API for
multi-resolution image.
y
y/2
x/2
x

54. 252: Use CLDR Locale Data by
Default
•Use locale data from the
Unicode Common Locale
Data Repository.

55. 253: Prepare JavaFX UI Controls
& CSS APIs for Modularization
•To clean around JavaFX to
prepare for Project Jigsaw.

56. 254: Compact Strings
•String class diet.

57. 255: Merge Selected Xerces
2.11.0 Updates into JAXP
•To update JAXP from Xerces
2.7.1 to 2.11.0.

58. 256: BeanInfo Annotations
•Replace @beaninfo .
•@interface JavaBean {…}
•@interface BeanProperty {…}
•@interface SwingContainer{…}

59. 257: Update JavaFX/Media to
Newer Version of GStreamer
•Update GStreamer.
•GStreamer: multimedia
framework.

60. 258: HarfBuzz Font-Layout Engine
•Replace OpenType font-
layout engine from ICU to
HarfBuzz.

61. Important features for me.
•sun.misc.Unsafe alternatives.
•G1GC by default.
•Project Jigsaw.
•JIT compiler is more friendly.
•jshell