Java’s Project Leyden arrives in early-access build

The OpenJDK’s Project Leyden, an effort to improve the startup time, time to peak performance, and footprint of Java programs, has published its first early-access build.

Accessible from java.jdk.net, the initial Project Leyden release focuses on improving application startup time, according to a June 24 bulletin on the Oracle Java team’s Inside Java website. Other Leyden optimizations will be explored in future releases. The easiest way to start with Leyden features is by using the java program in the Leyden Early Access Release with the -XX:CacheDataStore flag. Project Leyden is sponsored by Java’s HotSpot and Core Libraries groups.

Other highlights of the build include ahead-of-time (AOT) compilation of Java methods to natively execute them as soon as the application starts up in the production run, and ahead-of-time resolution of constant pool entries, allowing the AOT compiler to produce better code and speed application starts.

The Project Leyden early-access build also includes:

• Archived method profiles for reaching Java application performance quicker.
• A unified Cache Data Store archive that simplifies creation of the CDS archive, while supporting multiple types of optimization artifacts.
• Ahead-of-time generation of dynamic proxies and reflection data. Frameworks use dynamic proxies extensively during startup time.
• Loaded classes in the CDS archive when the application starts up.
• A class loader lookup cache that helps application frameworks perform repeated lookups without repeatedly scanning the classpath.

Developers can provide feedback to the Project Leyden mailing list. A subscription is required.

Paul Krill is an editor at large at InfoWorld, whose coverage focuses on application development.