Efforts to enhance Java program startup times and efficiency are set to include enhancing assistance for archived Java heap items in CDS (class data sharing).
The strategy, revealed by Ioi Lam of Oracle in an OpenJDK neighborhood RFC last month, lines up with Task Leyden, an effort to improve startup times for Java applications along with times to peak efficiency and program footprints. Lam noted that Job Leyden is most likely to make comprehensive usage of archived Java heap objects.Goals of the CDS
enhancement strategy include consistent support of CDS for all collectors and minimizing the code needed for each collector to support CDS. CDS itself is intended to lower application start-up times, in specific for smaller sized applications. CDS is supported only with the Java HotSpot client VM and only with the serial garbage collector.The CDS enhancement plan requires: Eliminating the G1 garbage man dependency for writing the archive load
- ; a working prototype already has actually been established. Consolidating the archive heap into an adjoining block. The intent is to make it simple to mmap(memory map)the archive stack into different collectors. Removal of G1 archive region types likewise is prepared as part of this step. Application of mmap of the archive region for other collectors. The execution is anticipated to be fairly simple.
- Since Java Advancement Kit (JDK)20, which is due as a production release in March, implementers of the plan should deal with restrictions including CDS archive discarding just being supported by the G1 collector, G1 having a special allowance routine for area in the load, and mmap supported only in G1.Providing the inspiration for the CDS proposal was a Java development plan to have consistent APIs for using archived regions. That proposition was launched this past November.
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