On Mon, 27 Nov 2023 22:52:10 GMT, Hans Boehm <d...@openjdk.org> wrote:
>> Brent Christian has updated the pull request incrementally with one >> additional commit since the last revision: >> >> Updates to clear() and enqueue() > > src/java.base/share/classes/java/lang/ref/package-info.java line 109: > >> 107: * >> 108: * <li>The clearing of a reference by the garbage collector >> <i>happens-before</i> >> 109: * the garbage collector enqueues the reference.</li> > > Is it worth specifying this middle step? Is there a way to tell that > something has been enqueued without removing the reference or calling the > deprecated (and very dubious) isEnqueued method? Could we just remove this > paragraph, and instead start the next one with "The clearing of a reference > by the garbage collector ..." Here, we are building a chain of _happens-befores_ that reaches from RF to dequeue (and on, to the running of the cleaning action, in the case of Cleaner). A ref can also be cleared by a call to clear(), but that has no memory consistency effects. So I think it's worth clarifying here that ref-clearing only forms a "link" in the _happens-before_ chain **_when performed by the GC_**. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/16644#discussion_r1472189769
