Integrated: 8052260: Reference.isEnqueued() spec does not match the long-standing behavior returning true iff it's in the ref queue

[Mandy Chung]

On Tue, 8 Dec 2020 02:36:01 GMT, Mandy Chung <mchung at openjdk.org> wrote:

> `Reference::isEnqueued` method was never implemented as it was initially specified since 1.2. The specification says that it tests if this reference object has been enqueued, but the long-standing behavior is to test if this reference object is in its associated queue, only reflecting the state at the time when this method is executed. The implementation doesn't do what the specification promised, which might cause serious bugs if unnoticed. For example, an application that relies on this method to release critical resources could cause serious performance issues, in particular when this method is misused on Reference objects without an associated queue.  `Reference::refersTo(null)` is the better recommended way to test if a Reference object has been cleared.
> 
> This proposes to deprecate `Reference::isEnqueued`.  Also the spec is updated to match the long-standing behavior.
> 
> CSR: https://bugs.openjdk.java.net/browse/JDK-8189386

This pull request has now been integrated.

Changeset: 5f033412
Author:    Mandy Chung <mchung at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/5f033412
Stats:     28 lines in 2 files changed: 22 ins; 0 del; 6 mod

8052260: Reference.isEnqueued() spec does not match the long-standing behavior returning true iff it's in the ref queue

Reviewed-by: kbarrett, alanb

-------------

PR: https://git.openjdk.java.net/jdk/pull/1684