GeeCON 2023: Jarosław Pałka - Bare metallic Java

Java, in fact JVM, has a well-deserved fame as a hardware-unfriendly platform, and so nobody (except Apache Kafka, Elastic, Cassandra and Neo4j) will build databases, queues and another solutions where 'mechanical sympathy' is crucial , in Java. Garbage collector, speculating JIT, deficiency of control over 'object layout', terrible support (mostly due to deficiency of abstraction) for modern processors and operating systems. And there is besides JNI (who was there, I know what I'm talking about). (I do not mention the implementation of IO) The intent of this presentation is to disenchant these myths and to show how much effort has late been going into making JVM more hardware friendly. It will be about APIs which are inactive in the incubation phase. You may never see these APIs in your life, but they will be a foundation of databases, queue brokers and game engines (I am not joking) in the future. I will focus on a abroad functions & memory JEP. We will learn how to work with native memory (with seatbelts fastened), downcall and upcall C functions from Java (with ease). Everything will be dipped in a sauce of broken examples and distorted micro benchmarks and OpenJDK compiled 5 minutes before the presentation.