How is Java / JVM built ? Adopt OpenJDK is your answer !

Java

●●●●●

●●●●●

●●●●●●

2006 2007 2010 Beyond

Sun launches OpenJDK(javac, Hotspot)

Rest of OpenJDK

is released Oracle adopts OpenJDK(Sun is acquired)

Lambdas, Nashorn & Adopt OpenJDK

OpenJDK:Reference implementation of Java 7 SE

Java 10

Java 9

2011 2012 2014

Java 8

World-wide Community involvement

… JDK6 ⇒ OpenJDK7 → JDK7 JDK7 ⇒ OpenJDK8 → JDK8 JDK8 ⇒ OpenJDK9 → JDK9 …

⇒ applied to→ produces

JDK7 ⇒ OpenJDK8 → JDK8* (1) JDK8* ⇒ OpenJDK8 → JDK8 (2)

⇒ applied to→ produces

make $ make [clean] images$ make bootcycle-images$ make [component-name]$ make [module-name]$ make JOBS=<n> # Run <n> parallel make jobs

GenCollectorPolicy* gc_policy;

if (UseSerialGC) { gc_policy = new MarkSweepPolicy(); } else if (UseConcMarkSweepGC) { #ifndef SERIALGC if (UseAdaptiveSizePolicy) { gc_policy = new ASConcurrentMarkSweepPolicy(); } else { gc_policy = new ConcurrentMarkSweepPolicy(); } #else // SERIALGC fatal("UseConcMarkSweepGC not supported in this VM."); #endif // SERIALGC } else { // default old generation gc_policy = new MarkSweepPolicy(); }

Universe::_collectedHeap = new GenCollectedHeap(gc_policy);

$ git clone <repo-name>

$ git pull origin master

$ mvn clean install

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

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

$ ./get_source.sh

$ bash configure --with-boot-jdk=<path to jdk8 image>

$ make clean images

$ make install

●●●●●

●●●●●●●●

See Resources section at the bottom of the page

Java

… JDK6 ⇒ OpenJDK7 → JDK7 JDK7 ⇒ OpenJDK8 → JDK8 JDK8 ⇒ OpenJDK9 → JDK9 …

⇒ applied to→ produces

make $ make [clean] images$ make bootcycle-images$ make [component-name]$ make [module-name]$ make JOBS=<n> # Run <n> parallel make jobs

$ git clone <repo-name>

$ git pull origin master

$ mvn clean install

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

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

$ ./get_source.sh

$ bash configure --with-boot-jdk=<path to jdk8 image>

$ make clean images

See Resources section at the bottom of the page