Class GoRefQueue

bind/java/Seq.java:252–280

	// GoRefQueue is a queue of GoRefs that are no longer live. An internal thread
	// processes the queue and decrement the reference count on the Go side.
	static class GoRefQueue extends ReferenceQueue<GoObject> {
		// The set of tracked GoRefs. If we don't hold on to the GoRef instances, the Java GC
		// will not add them to the queue when their referents are reclaimed.
		private final Collection<GoRef> refs = Collections.synchronizedCollection(new HashSet<GoRef>());

		void track(int refnum, GoObject obj) {
			refs.add(new GoRef(refnum, obj, this));
		}

		GoRefQueue() {
			Thread daemon = new Thread(new Runnable() {
				@Override public void run() {
					while (true) {
						try {
							GoRef ref = (GoRef)remove();
							refs.remove(ref);
							destroyRef(ref.refnum);
							ref.clear();
						} catch (InterruptedException e) {
							// Ignore
						}
					}
				}
			});
			daemon.setDaemon(true);
			daemon.setName("GoRefQueue Finalizer Thread");
			daemon.start();
		}
	}

	// A GoRef is a PhantomReference to a Java proxy for a Go object.
	// GoRefs are enqueued to the singleton GoRefQueue when no longer live,