private WeakEventSource(SimpleImmutableSet<IMakeEventCallbacks> callbacks)
{
if (callbacks == null)
throw new ArgumentNullException("callbacks");
if (callbacks.Any(c => c == null))
throw new ArgumentException("Null reference encountered in callbacks set");
_callbacks = callbacks;
}
public void Fire(object sender, TEventArgs e)
{
// Note: Not checking for null "sender" or "e" references here since any contracts an event may have that these
// should or should not support nulls are not for us to deal with here
var haveAnyCallbacksExpired = false;
var callbacksCopy = _callbacks;
foreach (var callback in callbacksCopy)
{
var didCallbackExecute = callback.ExecuteCallbackIfTargetStillAlive(sender, e);
if (!didCallbackExecute)
haveAnyCallbacksExpired = true;
}
if (haveAnyCallbacksExpired)
{
lock (_callbacks)
{
_callbacks = _callbacks.RemoveWhere(c => !c.IsTargetStillAlive);
}
}
}