The class-file API, beforehand previewed in JDK 22 and JDK 23, can be finalized in JDK 24, with minor adjustments. This API supplies a typical API for parsing, producing, and reworking Java class information. It goals to offer an API for processing class information that tracks the category file format outlined by the Java Digital Machine specification. A second objective is to allow JDK elements emigrate to the usual API, and finally take away the JDK’s inner copy of the third-party ASM library. Adjustments because the second preview embody a renaming of enum values, removing of some fields, the addition of strategies and methodology overloads, strategies renamed, and removing of interfaces and strategies deemed pointless.
Late barrier growth for the G1 rubbish collector is meant to simplify the implementation of G1’s limitations. The G1 rubbish collector’s limitations document details about utility reminiscence accesses, by shifting their growth from early within the C2 compilation pipeline to later. Objectives embody lowering the execution time of C2 compilation when utilizing the G1 collector, making G1 limitations understandable to HotSpot builders who lack a deep understanding of C2, and guaranteeing that C2 preserves invariants concerning the relative ordering of reminiscence accesses, safepoints, and limitations. A fourth characteristic is preserving the standard of C2-generated JIT (just-in-time)-compiled code, when it comes to pace and dimension.
The primary JDK 24-targeted characteristic, formally referred to as “Put together to Prohibit the Use of JNI,” requires issuing warnings about makes use of of JNI and adjusting the overseas perform and reminiscence (FFM) API, featured in JDK 22, to subject warnings in a constant method. These warnings are meant to arrange for a future launch that ensures integrity by default by uniformly limiting JNI and the FFM API. Objectives of the plan embody preserving JNI as a typical strategy to interoperate with native code, making ready the Java ecosystem for future releases that disallow interoperation with native code by default, and aligning the usage of JNI and the FFM API so library maintainers can migrate from one to the opposite with out requiring builders to alter command-line choices.
