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);
}
