Native events

[Guy Fawkes]

Hi,
I am trying to implement an embedded Java program that interacts and gets async events from native code. I need multiple Java threads, so my understanding is that I should not block inside a native function.
I understand I can get the events by polling from a Java thread, but that is too inefficient for the application I am working on.
Question then is, could anyone suggest a good way to get the async events from the native 'C' code into the Java KVM ? If possible, pointing me to sample 'C' and Java code that does it would be fantastic.
TIA.
Guy.