Registration cancelAfterUse does not guarantee that a Consumer will only be called once

[reactor]

Registration cancelAfterUse does not guarantee that a Consumer will only be called once

[smaldini]

I think this is related to the dispatcher strategy choice you make: use blockingQueue/RingBuffer and you behave like an actor - so no race condition. This comes with ThreadPoolDispatcher and we can certainly document it

[wilkinsona]

The Dispatcher doesn't matter. The race is between the thread(s) driving Reactor.notify and the thread that's making the registration and then calling cancelAfterUse. Even if your Reactor is using a synchronous dispatcher this can still race.

[smaldini]

I see what you mean, been mislead by the fact that cancelAfterUse is checked after the task is invoked (so still in the dispatcher), but you call cancelAfterUse after reactor.on() so another thread has a chance to notify it.