On Tue, 14 Nov 2023 14:06:29 GMT, Alan Bateman <al...@openjdk.org> wrote:
>> Classes in the `java.lang.ref` package would benefit from an update to bring >> the spec in line with how the VM already behaves. The changes would focus on >> _happens-before_ edges at some key points during reference processing. >> >> A couple key things we want to be able to say are: >> - `Reference.reachabilityFence(x)` _happens-before_ reference processing >> occurs for 'x'. >> - `Cleaner.register()` _happens-before_ the Cleaner thread runs the >> registered cleaning action. >> >> This will bring Cleaner in line (or close) with the memory visibility >> guarantees made for finalizers in [JLS >> 17.4.5](https://docs.oracle.com/javase/specs/jls/se18/html/jls-17.html#jls-17.4.5): >> _"There is a happens-before edge from the end of a constructor of an object >> to the start of a finalizer (ยง12.6) for that object."_ > > src/java.base/share/classes/java/lang/ref/Reference.java line 393: > >> 391: * Clears this reference object. Invoking this method does not >> enqueue this >> 392: * object, and the garbage collector will no longer enqueue this >> object once >> 393: * the referent reaches the designated reachability level. > > I'm wondering if "designated reachability level" is the right words to use > here. The Notification section in the package description speaks of when the > reachability of the referent has changed to the value corresponding to the > type of the reference and I wonder if it might be better to use wording > consistent with that. Minimally it could link to the package description > where the notion of reachability level is introduced. Perhaps it's sufficient to say simply that, _"the garbage collector will no longer enqueue this object."_ ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/16644#discussion_r1394969775
