Michał Warecki

OpenJDK HackathonBuilding and extending OpenJDK

Outline

● Introduction to OpenJDK● Building OpenJDK● Extending OpenJDK● Introduction to Jtreg

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OpenJDK

● Reference implementation of JLS and JVM● Open source● Tools (JVisualVM, JMH, jHAT etc.)● Extensions (e. g. Nashorn)

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OpenJDK

[michal@michal openjdk8]$ tree -L 1 -d

├── build

├── common

├── corba

├── hotspot

├── jaxp

├── jaxws

├── jdk

├── langtools

├── make

├── nashorn

└── test

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Download the code!

$ hg clone http://hg.openjdk.java.net/jdk8/jdk8 openjdk8

$ cd openjdk8

$ chmod a+x get_source.sh

$ ./get_source.sh

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Alternatives (try it!)

● Brand new Shenandoah GC:

$ hg clone http://icedtea.classpath.org/hg/shenandoah/openjdk8 shenandoah

● Java 9:

$ hg clone http://hg.openjdk.java.net/jdk9/dev 9dev

Look at the code!

10 minutes

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Build the code!

$ chmod a+x configure

$ bash configure

$ make clean images

(yes, that's it, simple)

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Extend OpenJDK

Follow the leading

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Run the test!

https://github.com/michalwarecki/OpenJDKHackaton.git

$ ./run_test.sh $DIR_OR_TEST_TO_RUN

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Look at the test code!

Follow the leading

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Make your own extension!

20 minutes

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Thanks!