This post is my live blog from KCDC. For more, see the 2021 KCDC live blog TOC

Speaker: Carl Dea (Azul)

Twitter: @carldea

————————-

Foojay.io has more

JEP 412 – Foreign Access API

• https://openjdk.java.net/jeps/412 – ties together other JEPs
• incubator module. Third incubabor
• in making for at teast 6 years

Problems with old way

• Communicating with required wrapper code and distributing a .ddl
• Have to do a lo of work yourself to interfaces with C

URLs

• jdk.java.net/panama
• https://github.com/openjdk/panama-foreign
• panama-dev@openjdk.java.net
• https://foojay.io/today/project-panama-for-newbies-part-1/
• https://foojay.io/today/project-panama-for-newbies-part-2/
• https://foojay.io/today/project-panama-for-newbies-part-3/
• https://github.com/carldea/panama4newbies

Using

• java -version. Make sure says 17-panama. (Not part of main JDK)
• jextract -h to get help
• jextract will generate Java code for you by looking at C header file
• Most important options
  • -I (capital Eye) – include file path
  • -d – destination for generate files
  • -l (lowercase ell) – specify a library
  • -t – target package
• Must add incubator module and enable native access flag to run
• Can call C methods from Java by importing them
• Java wil hande the memory allocation/cleanup based on scope

Include

• Copies file and puts in this file.
• Not like import where it a reference

My take

This is a topic I knew nothing about. (Or forgot what I had known.) It was really cool to see!