These are the slides of the Tools in Action I gave at Devoxx Belgium 2019. The JDK is an open source project that you can download and build yourself! All the new things under work are available on Mercurial branches, that you can get and compile to test them before they are released. It allows you to play with them, see how they work, see what do the new syntaxes look like. In short: you can play now with a JDK from the future, that may never exist! We will show how all this work, from the installation of a Ubuntu virtual machine to the execution of a home made JDK that will never be released.

1. #DevoxxFR
Building Your Own
JDK In 10 Steps
José Paumard
@JosePaumard

2. #Devoxx @JosePaumard
Why building your own JDK?
For the fun of it!
You can build JDKs that do not exist yet!
And that will never exist!!
Are they really JDKs though? Hmmm… (TCK?)

3. #Devoxx @JosePaumard
Why building your own JDK?
And in fact you do not have to do it yourself!

4. #Devoxx @JosePaumard
Why building your own JDK?
And you can even get…

5. #Devoxx @JosePaumard
Why building your own JDK?
https://hg.openjdk.java.net/
Top level repository of the Open JDK
65 projets available:
- amber, valhalla, loom, panama
- graal
- duke

6. #Devoxx @JosePaumard
Are you really building a JDK?
In fact no…
There is this TCK = Test Compatibility Kit
You need a licence to run it
LondonJug (LJC): Adopt OpenJDK
https://adoptopenjdk.net/
12 plateforms, 6 versions, 2 JVM

7. #Devoxx @JosePaumard
Let us start!
It needs some intallations
- Starting with Ubuntu Desktop 18.04
- Mercurial is not in the default installation
$ sudo apt-get install mercurial

8. #Devoxx @JosePaumard
Structure of the repository
http://hg.openjdk.java.net/valhalla/

9. #Devoxx @JosePaumard
Structure of the repository
http://hg.openjdk.java.net/amber/

10. #Devoxx @JosePaumard
Structure of the repository
http://hg.openjdk.java.net/loom/

11. #Devoxx @JosePaumard
Structure of the repository
http://hg.openjdk.java.net/loom/loom/

12. #Devoxx @JosePaumard
This is loom we want!
$ hg clone http://hg.openjdk.java.net/loom/loom/
ubuntu@ubuntu:~/jdk-builds/loom$ ls -l
total 60
-rw-r--r-- 1 ubuntu ubuntu 2114 Apr 10 11:51 ADDITIONAL_LICENSE_INFO
-rw-r--r-- 1 ubuntu ubuntu 1522 Apr 10 11:51 ASSEMBLY_EXCEPTION
drwxr-xr-x 3 ubuntu ubuntu 4096 Apr 10 11:51 bin
-rw-r--r-- 1 ubuntu ubuntu 1649 Apr 10 11:51 configure
drwxr-xr-x 3 ubuntu ubuntu 4096 Apr 10 11:51 doc
-rw-r--r-- 1 ubuntu ubuntu 19274 Apr 10 11:51 LICENSE
drwxr-xr-x 23 ubuntu ubuntu 4096 Apr 10 11:51 make
-rw-r--r-- 1 ubuntu ubuntu 2785 Apr 10 11:51 Makefile
-rw-r--r-- 1 ubuntu ubuntu 341 Apr 10 11:51 README
drwxr-xr-x 78 ubuntu ubuntu 4096 Apr 10 11:51 src
drwxr-xr-x 14 ubuntu ubuntu 4096 Apr 10 11:51 test

13. #Devoxx @JosePaumard
This is loom we want!
$ hg clone http://hg.openjdk.java.net/loom/loom/
$ du -s *
2542764 loom
2555176 valhalla

14. #Devoxx @JosePaumard
Here the repo is not up to date
Updating a local repo
$ hg branches
fibers 54840:2c84b04740e1
processorid 54156:df063b0c6b16
cont 54839:8d1717a86bcc (inactive)
default 54838:9d0ae9508d53 (inactive)

15. #Devoxx @JosePaumard
Updating a local repo
$ hg pull
pulling from http://hg.openjdk.java.net/loom/loom/
searching for changes
adding changesets
adding manifests
adding file changes
added 1692 changesets with 11645 changes to 7333 files
new changesets 283cecb991fa:27a4185098e8
(run 'hg update' to get a working copy)
$ hg branches
fibers 56532:27a4185098e8
processorid 55689:7e07b78cbf78
cont 56531:9ae91a14c0f7 (inactive)
default 56521:ececb6dae777 (inactive)

16. #Devoxx @JosePaumard
Branches
For Amber
$ hg branches
records 58586:367756dce66a
local-methods 58581:ef0e9ad164da
lambda-leftovers 58561:a9d1988be315
stats-before-this-super 58560:8c5aafc6c2c1
pattern-runtime 58559:83136411a3a0
records-and-sealed 58352:e62676fdb665
patterns-stage-1 58335:449afd3008d5
amber-demo-II 57904:c3e3f3b41490
patterns-deconstruction 57856:aa7b2dbc1a2a
concise-method-declarations 56872:e16b2019df86
enhanced-enums 56869:d521c8687ea8
default 58558:1bd307ea5497 (inactive)
patterns 57025:a898dc684456 (inactive)

17. #Devoxx @JosePaumard
Choosing a branch
For Amber
$ hg amber-demo-II
records 58586:367756dce66a
local-methods 58581:ef0e9ad164da
lambda-leftovers 58561:a9d1988be315
stats-before-this-super 58560:8c5aafc6c2c1
pattern-runtime 58559:83136411a3a0
records-and-sealed 58352:e62676fdb665
patterns-stage-1 58335:449afd3008d5
amber-demo-II 57904:c3e3f3b41490
patterns-deconstruction 57856:aa7b2dbc1a2a
concise-method-declarations 56872:e16b2019df86
enhanced-enums 56869:d521c8687ea8
default 58558:1bd307ea5497 (inactive)
patterns 57025:a898dc684456 (inactive)

18. #Devoxx @JosePaumard
Configuring the compilation
Autoconf FTW!
$ ./configure
Runnable configure script is not present
Generating runnable configure script at /home/ubuntu/jdk-builds/loom/build/.configure-
support/generated-configure.sh
Autoconf is not found on the PATH, and AUTOCONF is not set.
You need autoconf to be able to generate a runnable configure script.
You might be able to fix this by running 'sudo apt-get install autoconf’.
$ sudo apt-get install autoconf

19. #Devoxx @JosePaumard
Configuring the compilation
Autoconf FTW!
$ ./configure
configure: error: Cannot find GNU make 3.81 or newer! Please put it in the path, or add
e.g. MAKE=/opt/gmake3.81/make as argument to configure.
$ sudo apt-get install make

20. #Devoxx @JosePaumard
Configuring the compilation
Autoconf FTW!
$ ./configure
configure: error: Could not find a C compiler. You might be able to fix this by running
'sudo apt-get install build-essential'.
configure exiting with result code 1
$ sudo apt-get install build-essential (117Mo)

21. #Devoxx @JosePaumard
Configuring the compilation
Autoconf FTW…
$ ./configure
configure: error: Could not find X11 libraries. You might be able to fix this by running
'sudo apt-get install libx11-dev libxext-dev libxrender-dev libxrandr-dev libxtst-dev
libxt-dev'.
configure exiting with result code 1
$ sudo apt-get install libx11-dev libxext-dev libxrender-dev libxrandr-dev libxtst-dev
libxt-dev (20Mo)

22. #Devoxx @JosePaumard
Configuring the compilation
Autoconf FTW??
$ ./configure
configure: error: Could not find cups! You might be able to fix this by running 'sudo
apt-get install libcups2-dev'.
configure exiting with result code 1
$ sudo apt-get install libcups2-dev

23. #Devoxx @JosePaumard
Configuring the compilation
Autoconf FTW 
$ ./configure
configure: error: Could not find alsa! You might be able to fix this by running 'sudo
apt-get install libasound2-dev'.
configure exiting with result code 1
$ sudo apt-get install libasound2-dev

24. #Devoxx @JosePaumard
Configuring the compilation
Autoconf FTW ☺
A new configuration has been successfully created in
/home/ubuntu/jdk-builds/loom/build/linux-x86_64-server-release
using default settings.
Configuration summary:
* Debug level: release
* HS debug level: product
* JVM variants: server
* JVM features: server: 'aot cds cmsgc compiler1 compiler2 epsilongc g1gc graal jfr jni-check jvmci jvmti management
nmt parallelgc serialgc services shenandoahgc vm-structs zgc'
* OpenJDK target: OS: linux, CPU architecture: x86, address length: 64
* Version string: 13-internal+0-adhoc.ubuntu.amber (13-internal)
Tools summary:
* Boot JDK: openjdk version "12" 2019-03-19 OpenJDK Runtime Environment (build 12+33) OpenJDK 64-Bit Server VM
(build 12+33, mixed mode, sharing) (at /home/ubuntu/jdk/jdk-12)
* Toolchain: gcc (GNU Compiler Collection)
* C Compiler: Version 7.3.0 (at /usr/bin/gcc)
* C++ Compiler: Version 7.3.0 (at /usr/bin/g++)
Build performance summary:
* Cores to use: 4
* Memory limit: 7953 MB

25. #Devoxx @JosePaumard
Launching the compilation
Make FTW! (make clean first…)
$ make images
Building target 'images' in configuration 'linux-x86_64-server-release'
Compiling 8 files for BUILD_TOOLS_LANGTOOLS
Compiling 1 files for BUILD_JFR_TOOLS
Creating hotspot/variant-server/tools/adlc/adlc from 13 file(s)
Compiling 2 files for BUILD_JVMTI_TOOLS
...

26. #Devoxx @JosePaumard
Launching the compilation
Make FTW!
$ make images
...
Creating support/demos/image/jfc/SampleTree/SampleTree.jar
Creating support/demos/image/jfc/TableExample/TableExample.jar
Creating support/demos/image/jfc/TransparentRuler/TransparentRuler.jar
Creating jdk image
Creating CDS archive for jdk image
Stopping sjavac server
Finished building target 'images' in configuration 'linux-x86_64-server-release'
$ du -s *
6287440 loom
6358412 amber

27. #Devoxx @JosePaumard
Result?
The result is in server-release/images/jdk/
$ ls -l build/linux-x86_64-server-release
total 120
-rw-r--r-- 1 ubuntu ubuntu 2663 Apr 15 02:21 bootcycle-spec.gmk
-rw-r--r-- 1 ubuntu ubuntu 7869 Apr 15 02:21 buildjdk-spec.gmk
-rw-r--r-- 1 ubuntu ubuntu 17895 Apr 15 02:31 build.log
drwxr-xr-x 19 ubuntu ubuntu 4096 Apr 15 02:31 buildtools
-rwxr-xr-x 1 ubuntu ubuntu 3908 Apr 15 02:21 compare.sh
-rw-r--r-- 1 ubuntu ubuntu 14971 Apr 15 02:21 configure.log
drwxr-xr-x 2 ubuntu ubuntu 4096 Apr 15 02:21 configure-support
drwxr-xr-x 3 ubuntu ubuntu 4096 Apr 15 02:22 hotspot
drwxr-xr-x 5 ubuntu ubuntu 4096 Apr 15 02:31 images
drwxr-xr-x 8 ubuntu ubuntu 4096 Apr 15 02:31 jdk
-rw-r--r-- 1 ubuntu ubuntu 1261 Apr 15 02:21 Makefile
drwxr-xr-x 6 ubuntu ubuntu 4096 Apr 15 02:22 make-support
-rw-r--r-- 1 ubuntu ubuntu 33489 Apr 15 02:21 spec.gmk
drwxr-xr-x 22 ubuntu ubuntu 4096 Apr 15 02:31 support

28. #Devoxx @JosePaumard
Result?
Result!
$ export JAVA_HOME= .../amber/build/linux-x86_64-server-release/images/jdk
$ export PATH=$JAVA_HOME/bin:$PATH
$ java –version
openjdk version "13-internal" 2019-09-17
OpenJDK Runtime Environment (build 13-internal+0-adhoc.ubuntu.amber)
OpenJDK 64-Bit Server VM (build 13-internal+0-adhoc.ubuntu.amber, mixed mode, sharing)

29. #Devoxx @JosePaumard
Wrapping up
A little tricky…
A little long!
Needs to make your hand dirty to test new functionalities
You will be fighting against your IDE, and you will loose!
But you can follow what is going on in real-time ☺

30. #DevoxxFR
It’s your turn!
José Paumard
@JosePaumard