Webtagr - Technology News Summarizer

JDK 25: String Performance Boost via Hash Code Constant Folding

2025-05-02

JDK 25 significantly improves the performance of the String class by enabling constant folding of the String::hashCode function. This leads to substantial speedups, especially when using Strings as keys in static, immutable Maps, such as in a scenario where MethodHandles for native calls are accessed via String keys. Benchmarks show over an 8x improvement. This optimization is achieved by marking the internal String.hash field with the @Stable annotation. This allows the JVM to cache and reuse the hash code, avoiding recomputation for non-zero hash codes. While a zero hash code can hinder this optimization, a future fix is anticipated.

Deep Dive into JVM Startup

2025-01-09

Billy Korando from Oracle's Java team published an in-depth article on January 9, 2025, exploring the intricacies of JVM startup. The article provides a detailed look into the internal mechanisms of JVM initialization, offering valuable insights for Java developers. Readers are encouraged to check the video description for further information.

Valhalla: Java's Epic Refactor Nears Completion

2024-12-17

After a decade-long journey, Project Valhalla, Java's ambitious refactor, is nearing completion. Aiming to bridge the gap between classes and primitives, Valhalla introduces value classes that offer the coding convenience of classes with the performance of primitives, resulting in a flat and compact memory layout. At Devoxx 2024, Java Language Architect Brian Goetz provided a comprehensive update, highlighting key features such as value classes, null-restricted types, enhanced definite assignment analysis, and strict initialization.