PerformanceSensitive

A marker annotation that signals that an event is highly sensitive, and should be handled very quickly. If heavy processing needs to be done for one of these events, it should be done asynchronously.

These events could be sensitive for a number of reasons. For example, an event like org.kryptonmc.api.event.player.PlayerMoveEvent is sensitive because it is fired very frequently, even if the server only has a couple of players. Tick start and tick end events are also called a lot, and your processing could severely limit the TPS capability of the server.