JDK 9, 10, 11 and Beyond: Delivering New Features in the JDK

Transcription

1 JDK 9, 10, 11 and Beyond: Delivering New Features in the JDK Copyright Azul Systems 2015 Simon Ritter Deputy CTO, Azul Systems 1

2 JDK 9: Big And Small Changes 2

3 Java Platform Module System (JPMS) The core Java libraries are now a set of modules (JEP 220) 75 OpenJDK modules: 27 Java SE, 48 JDK Oracle JDK: 14 additional JDK, 8 JavaFX, 2 Oracle specific Most internal APIs now encapsulated (JEP 260) sun.misc.unsafe Some can be used with command line options 3

4 jlink: The Java Linker (JEP 282) jlink Modular run-time image bin conf lib $ jlink --modulepath $JDKMODS \ --addmods java.base output myimage $ myimage/bin/java -list-modules java.base@9 4

5 jlink: The Java Linker (JEP 282) $ jlink --module-path $JDKMODS:$MYMODS \ --addmods com.azul.zapp -output myimage $ myimage/bin/java -list-modules java.base@9 java.logging@9 java.sql@9 java.xml@9 com.azul.zapp@1.0 com.azul.zoop@1.0 com.azul.zeta@1.0

6 Moving Java Forward Faster

7 Java Platform Development Development of releases takes time JDK 6: 2 years and 2 months after JDK 5 JDK 7: 4 years and 8 months after JDK 6 JDK 8: 2 years and 8 months after JDK 7 JDK 9: 3 years and 6 months after JDK 8 7

8 Migrating To A New Version Plenty of time to continue with previous release JDK 6: 2 years and 11 months of public JDK 5 updates JDK 7: 1 year and 9 months of public JDK 6 updates JDK 8: 1 year and 1 month of public JDK 7 updates Also allows for stabilisation of new platform before migrating applications in production 8

9 The Java Platform Today Stable Secure Free 9

10 OpenJDK: New Release Model A new version of the JDK will be released every six months March and September Started this year with JDK 10 and JDK 11 OpenJDK development will be more agile Previous target was a release every two years Features will be included only when ready Targeted for a release when feature complete 10

11 Long Term Support Releases Long term support for all releases is not practical One Long Term Support (LTS) release every three years JDK 8 has been classified as an LTS release JDK 8 public updates stop in January 2019 for commercial users Non-commercial users get updates until December 2020 Next LTS release is JDK 11 JDK 9 and JDK 10 are feature releases Updates for only six months 11

12 Which JDK Binary Traditional Oracle branded binary (java.oracle.com) Oracle Binary Code License (FoU restrictions) New OpenJDK binary (jdk.java.net) GPLv2 with CPE license (no restrictions) Security and bug fix updates only for six months Only until next JDK release Two scheduled updates No overlap of updates for previous version 12

13 Converged Binaries Oracle JDK OpenJDK Java SE OpenJDK & Oracle JDK Java SE JDK 11 and later JDK 10 and earlier

14 Converged Binaries (JDK 11) Some closed-source parts of the JDK will be open-sourced Flight recorder Mission control Others Other closed-source parts will be removed Browser Plugin Java Web Start JavaFX 14

15 JDK 9 Onwards And Compatibility "Clean applications that just depend on java.se should just work" - Oracle 15

16 JDK 9: The Clean Up Starts JDK 9 was a significant change for Java Deprecated APIs were removed for the first time Six methods and one class JDK 10 removed 1 package, 6 classes, 9 methods and 1 field Redundant features eliminated jhat tool, JVM TI hprof agent Numerous deprecated GC options removed Significant command line changes JDK 9 removed 187 -XX flags JDK 10 removed 36 -XX flags 16

17 Housekeeping Will Continue More significant removals in JDK 11 Applets, Browser Plugin, Web Start, JavaFX java.se.ee meta-module java.corba java.transaction java.activation java.xml.bind java.xml.ws java.xml.ws.annotation More in the future Nashorn deprecated, CMS garbage collector? 17

18 Compatibility Not Guaranteed New versions of Java may include breaking changes Anything for removal will be deprecated first Minimum of one release warning Could be only six months 18

19 Eliminating Confusion There will be an LTS release every three years This does NOT mean 3 years of free updates Oracle JDK (from JDK 11) can ONLY be used in production with a commercial support contract The only free JDK 11 and later will be OpenJDK binaries To continue to receive free updates to the JDK you MUST update your JDK EVERY SIX MONTHS JDK 8 can be used indefinitely for free But without any further security patches and bug fixes 19

20 New JDK Update Schedule

21 The Java Platform Soon Stable Secure Choose two out of three Free 21

22 JDK 10

23 Local Variable Type Inference JEP 286 Simple use cases var list = new ArrayList<String>(); // infers ArrayList<String> var stream = list.stream(); // infers Stream<String> Style guidelines available Good (appropriate use of variable name) var stringlist = List.of("a", "b", "c"); Poor var itemqueue = new PriorityQueue<>(); Infered type is PriorityQueue<Object> 23

24 JDK 10: JEPs JEP 307: Parallel Full GC for G1 Still a full GC with potentially big pauses JEP 310: Application Class-Data Sharing Previous commercial Oracle feature JEP 317: Experimental Java-based JIT compiler (Graal) JEP 319: Root Certificates default set of root CA certificates JEP 296: Consolidate JDK forests into single repo Eight repos becomes one 24

25 JDK 10: JEPs JEP 316: Heap allocation on alternative devices (Intel) NV-RAM with same semantics as DRAM JEP 313: Remove javah tool Same functionality through javac JEP 304: Garbage Collector Interface (Red Hat) Easier to add new algorithms (JVM internal) JEP 312: Thread-Local Handshakes Execute callbacks on threads without performing a global VM safepoint 25

26 JDK 10: APIs 73 New APIs List, Set, Map.copyOf(Collection) Collectors tounmodifiablelist tounmodifiablemap tounmodifiableset Optional.orElseThrow() 26

27 JDK 10: Miscellaneous XMLInputFactory.newFactory() de-deprecated (precated?) com.sun.security.auth package Six deprecated classes removed java.lang.securitymanager One deprecated field and seven methods removed JVM now more Docker container aware Uses container CPU count and memory size Namespace issues resolved (pids) 27

28 JDK 11

29 JDK JEPs 3 from outside Oracle JEP 318: Epsilon garbage collector (Red Hat) JEP 315: Improve Aarch64 intrinsics (Red Hat) JEP 331: Low overhead heap profiling (Google) 29

30 JDK 11: JEPs JEP 309: Dynamic Class-file constants Like invokedynamic but for class-file constants Bootstrap method used at runtime, not compile time Useful for compiler and language developers JEP 328: Flight Recorder Final piece of aligning OpenJDK and Oracle JDK 30

31 JDK 11: JEPs JEP 320: Remove CORBA and Java EE modules The power of a module system JEP 321: HTTP client HTTP/2 support Incubating module from JDK 9 standardised JEP 323: Local variable syntax for Lambda parameters Extending JEP 286 in JDK 10 (var x, var y) -> x.process(y) 31

32 JDK 11: JEPs JEP 324: Key Agreement with Curve25519 and Curve448 More efficient and secure than existing ECDH JEP 327: Unicode 10 8,518 new characters (seriously) Bitcoin symbol, Nishu, Soyombo, Zanabazar Square Long awaited (?) Colbert emoji 32

33 JDK 11: New APIs New methods but no new classes InputStream nullinputstream() Writer nullwriter() Path of(string, String...) 33

34 Longer Term JDK Futures

35 OpenJDK Projects Amber Simplifying syntax Valhalla Value types and specialised generics Loom Continuations and fibres Metropolis The JVM re-written in Java Panama FFI replacement for JNI 35

36 Project Amber JEP 286: Local variable type inference Delivered in JDK 10 JEP 323: Local variable syntax for Lambdas Will be delivered in JDK 11 36

37 Project Amber JEP 302: Lambda leftovers Single underscore for unused parameters JEP 326: Raw string literals (JDK 12) Use single backquote `c:\users\simon` ```A string with a `` in it``` 37

38 JEP 305: Pattern Matching Type test and switch statement support to start String formatted; switch (obj) { case Integer i: formatted = String.format("int %d", i); break; case Byte b: formatted = String.format("byte %d", b); break; case Long l: formatted = String.format("long %d", l); break; case Double d: formatted = String.format("double %f", d); break; case String s: formatted = String.format("String %s", s); break default: formatted = obj.tostring(); } 38

39 JEP 325: Switch Expressions (JDK 12) int numletters; switch (day) { case MONDAY: case FRIDAY: case SUNDAY: numletters = 6; break; case TUESDAY: numletters = 7; break; case THURSDAY: case SATURDAY: numletters = 8; break; case WEDNESDAY: numletters = 9; break; default: throw new IllegalStateException("Huh?: " + day); }; 39

40 JEP 325: Switch Expressions int numletters = switch (day) { case MONDAY, FRIDAY, SUNDAY -> 6; case TUESDAY -> 7; case THURSDAY, SATURDAY -> 8; case WEDNESDAY -> 9; default -> throw new IllegalStateException("Huh?: " + day); };

41 Project Valhalla Java has: Primitives: for performance Objects: for encapsulation, polymorphism, inheritance, OO Problem is where we want to use primitives but can't ArrayList<int> won't work ArrayList<Integer> requires boxing and unboxing, object creation, heap overhead, indirection reference 41

42 Project Valhalla Value types "Codes like a class, works like a primitive" Can have methods and fields Can implement interfaces Can use encapsulation Can be generic Can't be mutated Can't be sub-classed 42

43 Project Loom Further work on making concurrent programming simpler Threads are too heavyweight Loom will introduce fibres JVM level threads (remember green threads?) Add continuations to the JVM Use the ForkJoinPool scheduler Much lighter weight than threads Less memory Close to zero overhead for task switching 43

44 Project Metropolis Run Java on Java Rewrite most of the JVM in Java Use the Graal compiler project as significant input Easier ports to new platforms Less native code to modify and compile Faster new features on front-end Easier to write Java than C++ Performance is an issue to be explored and resolved AOT compiler in JDK 9 is the start of this 44

45 Azul's Zulu Java

46 Zulu Java Azul s free binary distribution of OpenJDK Passes all TCK tests JDK 6, 7, 8, 9,10 and 11 (EA) available Wider platform support: Intel 64-bit Windows, Mac, Linux Intel 32-bit Windows and Linux ARM 32 and 64-bit PowerPC 46

47 Summary

48 Java Continues To Evolve Faster Java releases Feature release every 6 months Access to free updates is a consideration Lots of ideas to improve Java Value types, fibres, syntax improvements Zulu Java has wide platform and JDK version support Very reasonable cost for commercial support 48

49 Thank You! Copyright Azul Systems 2015 Simon Ritter Deputy CTO, Azul Systems 49