`Reference::refersTo` behaves the same for soft, weak, and phantom references whereas `PhantomReference::get` always returns `null` which is different than soft and weak references.
This patch clarifies the specification of `PhantomReference` to make it clear that `refersTo` can be used for phantom references. With `refersTo`, phantom references if not registered in a reference queue are not completely useless. Update the javadoc of the constructor to reflect that. I created a CSR to document this spec clarification: https://bugs.openjdk.java.net/browse/JDK-8269688 ------------- Commit messages: - JDK-8262841: Behavior of PhantomReference.refersTo is not well documented Changes: https://git.openjdk.java.net/jdk17/pull/181/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk17&pr=181&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8262841 Stats: 5 lines in 1 file changed: 2 ins; 2 del; 1 mod Patch: https://git.openjdk.java.net/jdk17/pull/181.diff Fetch: git fetch https://git.openjdk.java.net/jdk17 pull/181/head:pull/181 PR: https://git.openjdk.java.net/jdk17/pull/181
