Java final field semantics

Contrary to popular belief, a final field in Java is not the same thing as a final variable that may only be assigned to once. The Java memory model (JMM) not only has a separate section explaining the semantics but also introduces two partial orders—dereference chain (dereferences) and memory chain (mc) just for the sake of specifying final fields.

This presentation touches almost all aspects of the JMM and has many examples of programs which behavior a reader may find unexpected. I presented it to my colleagues at NetCracker Technology and at ZeptoLab. Vladimir Sitnikov, who is a co-author of the presentation, made a public talk in Russian.

Links to useful resources about the JMM

• Теоретический минимум для понимания Java Memory Model by Roman Elizarov (in Russian)
• Close Encounters of The Java Memory Model Kind by Aleksey Shipilëv
• Using JDK 9 Memory Order Modes by Doug Lea
• A Formalization of Java's Concurrent Access Modes by John Bender, Jens Palsberg