> On Oct 20, 2015, at 11:28 AM, Roger Riggs <[email protected]> wrote:
>
> Updated Javadoc:
> http://cr.openjdk.java.net/~rriggs/cleaner-doc/
I’m happy with this API to provide an easy way to migrate away from finalizers.
Some thoughts:
1. For an existing finalizer (say cleanup function), it will be replaced with
Cleaner.create().phantomCleanable(this, this::cleanup);
It may be useful to provide a sharable Cleaner instance that doesn’t go away.
The primary use for this Cleaner API is to replace finalizers. I wonder it
worths having a convenient method easier to relate to finalizer (say
Cleaner.finalizable?)
2. Do you know any existing use of soft / weak references in the JDK can
benefit from this automatic cleanup mechanism? The typical cache implementation
using soft/weak references is to purge the entries when the cache is accessed
and manages the reference queue without a background thread.
I’m in two minds that it sounds sensible for this Cleaner API to extend for
soft/weak references whereas I am not certain of the use cases. Anyone can
share the known use cases that would be helpful.
>
> Updated Webrev:
> http://cr.openjdk.java.net/~rriggs/webrev-cleaner-8138696/
57 final PhantomCleanable<?> phantomCleanableList;
59 final WeakCleanable<?> weakCleanableList;
61 final SoftCleanable<?> softCleanableList;
- is there any benefit of keeping separate list for each reference type? Each
cleaner has one single ReferenceRueue and it seems that keeping one single
Cleanable list could achieve similar performance in most cases while the
implementation might be simplified.
111 thread.setPriority(Thread.MAX_PRIORITY);
VM threads are near max priority. The reference handler thread is MAX_PRORITY
whereas the finalizer thread is MAX_PRIORITY-2. I think the cleaner thread
should not be of MAX_PRIORITY and also perhaps the caller may need a way to get
the thread associated with a Cleaner so that users can set the priority if
needed?
Mandy
