private void ExpiryTimer_Tick(ActiveHandlerTrackingEntry active) { // The timer callback should be the only one removing from the active collection. If we can't find // our entry in the collection, then this is a bug. var removed = _activeHandlers.TryRemove(active.Name, out var found); Debug.Assert(removed, "Entry not found. We should always be able to remove the entry"); Debug.Assert(ReferenceEquals(active, found.Value), "Different entry found. The entry should not have been replaced"); // At this point the handler is no longer 'active' and will not be handed out to any new clients. // However we haven't dropped our strong reference to the handler, so we can't yet determine if // there are still any other outstanding references (we know there is at least one). // // We use a different state object to track expired handlers. This allows any other thread that acquired // the 'active' entry to use it without safety problems. var expired = new ExpiredHandlerTrackingEntry(active); _expiredHandlers.Enqueue(expired); Log.HandlerExpired(_logger, active.Name, active.Lifetime); StartCleanupTimer(); }
// IMPORTANT: don't cache a reference to `other` or `other.Handler` here. // We need to allow it to be GC'ed. public ExpiredHandlerTrackingEntry(ActiveHandlerTrackingEntry other) { Name = other.Name; _livenessTracker = new WeakReference(other.Handler); InnerHandler = other.Handler.InnerHandler; }
private void StartHandlerEntryTimer(ActiveHandlerTrackingEntry entry) { entry.StartExpiryTimer(ExpiryTimer_Tick); }