To the Moon and Beyond With Java 17 APIs!

Since moving to a 6 monthly release cadence, the Java platform is evolving more dynamically than ever before. It can be quite a challenge to stay on top of all the changes and new features.

In this talk we're going to explore the most important developments in the Java API: which classes have been added, what has been removed? Join Duke, the Java mascot for a trip to space and learn which exciting new APIs provided by the Java platform can help him with his journey:

- The Java Vector API for utilizing the SIMD capabilities of modern CPU architectures
- The Foreign Linker API for integrating with native code
- The JFR Event Streaming API for publishing JDK Flight Recorder Events

We'll also take a look at some useful changes to the Java runtime, such as CDS archives for a faster spaceship..., uhm, application launch.

Transcript

1. To the Moon and Beyond With Java 17 APIs! Gunnar Morling Software Engineer, Red Hat @gunnarmorling
4. #Java17APIs @gunnarmorling “Commit [ourselves] to achieving the goal, before this decade talk is out, of landing a man Duke on the Moon and returning him safely to the Earth” Today’s Mission John F. Kennedy
5. The Vector API 1 JFR Event Streaming 2 3 The Foreign Linker API
6. #Java17APIs @gunnarmorling • Projects ◦ Debezium ◦ Quarkus ◦ Hibernate • MapStruct, JfrUnit, kcctl • Java Champion • @gunnarmorling Gunnar Morling Open Source Software Engineer at Red Hat
7. The Vector API 1
8. #Java17APIs @gunnarmorling The Vector API JEPs 338 / 414 / 417 java.util.Vector?!
9. #Java17APIs @gunnarmorling “Introduce an API to express vector computations that reliably compile at runtime to optimal vector instructions on supported CPU architectures, thus achieving performance superior to equivalent scalar computations.” The Vector API JEPs 338 / 414 / 417 JEP 417
10. #Java17APIs @gunnarmorling The Vector API Goals Clear and concise API 1 Reliable runtime compilation and performance on x64 (SSE, AVX) and AArch64 (NEON, SVE) 2 3 4 Platform agnostic Graceful degradation
11. #Java17APIs @gunnarmorling The Vector API Use Cases • Image, text, signal processing • Encryption • Machine Learning • etc.
12. #Java17APIs @gunnarmorling The Vector API Terminology
13. #Java17APIs @gunnarmorling The Vector API Example – Scalar c = -(a2 + b2)
14. #Java17APIs @gunnarmorling The Vector API Example – Vector
15. #Java17APIs @gunnarmorling The Vector API Example – Vector
16. #Java17APIs @gunnarmorling The Vector API Example – Vector
17. #Java17APIs @gunnarmorling The Vector API Example – Vector
18. #Java17APIs @gunnarmorling The Vector API Example – Vector
19. #Java17APIs @gunnarmorling The Vector API A Very Rich API
20. #Java17APIs @gunnarmorling The Vector API Example – FizzBuzz
21. #Java17APIs @gunnarmorling The Vector API FizzBuzz – Performance Benchmark Mode Cnt Score Error Units scalarFizzBuzz thrpt 5 2204774,792 ± 76581,374 ops/s simdFizzBuzz thrpt 5 8830433,250 ± 69955,161 ops/s MacBook Pro 2019 (2,6 GHz 6-Core Intel Core i7, 32GB RAM)
22. #Java17APIs @gunnarmorling The Vector API Examining Assembly Code with Hsdis
23. #Java17APIs @gunnarmorling The Vector API Examining Native Assembly "conditionally copies byte elements from the source operand to the destination operand depending on mask bits defined in the implicit third register argument" felixcloutier.com
24. Detour Identifying JDK API Changes by Yourself
25. #Java17APIs @gunnarmorling Detour: Identifying API Changes javaalmanac.io
26. #Java17APIs @gunnarmorling Detour: Identifying API Changes github.com/AdoptOpenJDK/jdk-api-diff
27. #Java17APIs @gunnarmorling Detour: Identifying API Changes chriswhocodes.com/jepsearch.html
28. #Java17APIs @gunnarmorling Detour: Identifying API Changes JavaDoc ab Version 17
29. 1 JFR Event Streaming 3 2 The Vector API The Foreign Linker API
30. #Java17APIs @gunnarmorling • Accessing native Memory (JEP 383) • Accessing native APIs (JEP 389) ◦ Moving specific parts to native code ◦ Using existing native libraries • Vector API Projekt Panama Integration of JVM and Native Code
31. #Java17APIs @gunnarmorling Foreign Linker API Using Method Handle
32. #Java17APIs @gunnarmorling Foreign Linker API Using Method Handle
33. #Java17APIs @gunnarmorling Foreign Linker API Using Method Handle
34. #Java17APIs @gunnarmorling • Provide or create header file • Generate binding (Panama EA build required) Foreign Linker API jextract
35. #Java17APIs @gunnarmorling Foreign Linker API jextract
36. #Java17APIs @gunnarmorling Foreign Linker API github.com/sundararajana/panama-jextract-samples
37. Detour Removed APIs
38. #Java17APIs @gunnarmorling • RMI Activation • Pack 200 • Nashorn JavaScript-Engine • Deprecated for Removal in Java 17 ◦ Applet API ◦ Security Manager Detour: Removed APIs Tackling the Maintenance Burden → 🤷 → 🤷 → Standalone Nashorn (ab Java 15), GraalJS
39. 1 JFR Event Streaming 2 3 The Vector API The Foreign Linker API
40. #Java17APIs @gunnarmorling OpenJDK Flight Recorder • “JVM framework for troubleshooting, monitoring and profiling” • 150+ built-in event types • Support for custom events • Open source since Java 11 • Meant for “Always on” usage in production
41. #Java17APIs @gunnarmorling JFR Event Types https://bestsolution-at.github.io/jfr-doc/
42. #Java17APIs @gunnarmorling JFR Event Streaming JEP 349 • Processing JFR events in “real-time” • Use Cases ◦ Export to monitoring services ◦ Performance tests (JfrUnit) ◦ Predictive analytics
43. #Java17APIs @gunnarmorling JFR Event Streaming API
44. #Java17APIs @gunnarmorling JFR Event Streaming Out-of-process: github.com/flight-recorder/health-report
45. #Java17APIs @gunnarmorling • Performance tests based on metrics like latency/throughput often unstable • JfrUnit ◦ Assertions based on proxy metrics ◦ Plain JUnit-Tests ◦ Analysis via JDK Mission Control JFR Event Streaming Use Case: Performance Regression Tests with JfrUnit “Unit testing, for performance”
46. #Java17APIs @gunnarmorling JFR Event Streaming Asserting Socket IO with JfrUnit
47. #Java17APIs @gunnarmorling JFR Event Streaming Asserting Socket IO with JfrUnit
48. #Java17APIs @gunnarmorling JFR Event Streaming Asserting Socket IO with JfrUnit
49. #Java17APIs @gunnarmorling JFR Event Streaming Asserting Socket IO with JfrUnit
50. #Java17APIs @gunnarmorling JFR Event Streaming Asserting Socket IO with JfrUnit
51. #Java17APIs @gunnarmorling JFR Event Streaming Asserting Socket IO with JfrUnit
52. Detour AppCDS
53. #Java17APIs @gunnarmorling • Class Data Sharing: Memory mapped class metadata • Default CDS archive for JDK classes since Java 12 (JEP 341) • AppCDS: CDS archive for your own classes Detour: Faster Start-up with AppCDS No Need to Go Native?
54. #Java17APIs @gunnarmorling Detour: AppCDS Quarkus App – Time to First Response Hetzner Cloud CX4 (4 vCPUs, 16GB RAM)
55. #Java17APIs @gunnarmorling Detour: AppCDS Start-up Time of Apache Kafka
57. #Java17APIs @gunnarmorling Java 17 – An Update Well Worth It! Many Improvements Across the Board... Language API Runtime
58. #Java17APIs @gunnarmorling • Shenandoah GC • JFR support for native GraalVM binaries • AArch64/Linux port • Project Lilliput Red Hat & OpenJDK Multiple Contributions
59. #Java17APIs @gunnarmorling • JEP Search https://chriswhocodes.com/jepsearch.html • Blog (Vector API, JFR Event Streaming, AppCDS, etc.) https://www.morling.dev/ • JfrUnit https://github.com/moditect/jfrunit Resources
60. #Java17APIs @gunnarmorling Q&A gunnar@hibernate.org @gunnarmorling 📧 Contact