Summary

In JDK 8, the jdk.net package was marked as @Exported(true), and was part of the rt.jar, and hence qualified to be included in the data used for --release 8, but it was not included. This change proposes to include the historical data for the jdk.net package, and also adds several updates to the JDK 8 data.

Problem

In JDK 8, the jdk.net package was marked as @Exported(true), and was part of the rt.jar, and hence qualified to be included in the data used for --release 8, but it was not included.

Solution

The jdk.net package will be enabled for the --release 8 data, and the historical data will be regenerated. The tool will be run on JDK 8u462, and a handful of APIs that have been added since last update of the historical data (which was related to JDK 8 MR3) will also be included.

The addition of the jdk.net package data ought to be overall safe.

The addition of the additional API updates is potentially more problematic, as compilation with --release 8 may succeed, but running on JDK 8 prior to JDK 8u462 may fail. This has already happened in the past on at least two occasions:

• the original --release 8 data actually contained Nashorn API introduced in JDK 8u40, not the JDK 8 GA version
• the historical data have been updated to cover JDK 8 MR 3 under https://bugs.openjdk.org/browse/JDK-8244763

Specification

The following is proposed:

• the historical data for original jdk.net package will be added
• java.lang.Character.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_E introduced by MR 5 will be added. This may have an impact on compilation, and code using this method compiled with --release 8 may not run on previous versions of JDK 8.
• java.lang.ref.Reference.clone() overload is added, introduced by MR 4 (although this shall not have a direct effect on compilations, as it is an overload of a method from a supertype)
• javax.swing.JSpinner.NumberEditor.setComponentOrientation overload is added, this shall not have a direct effect on compilations
• com.sun.management.ThreadMXBean is augmented with a handful of methods: getThreadInfo, dumpAllThreads and getCurrentThreadAllocatedBytes introduced in u282 and getTotalThreadAllocatedBytes introduced in u412. Those may have an impact on compilation, and code using this method compiled with --release 8 may not run on previous versions of JDK 8.
• jdk.net.ExtendedSocketOptions is augments with a handful of fields: TCP_KEEPIDLE, TCP_KEEPINTERVAL, TCP_KEEPCOUNT, introduced in u272. Those may have an impact on compilation, and code using this method compiled with --release 8 may not run on previous versions of JDK 8.