JNI calling JVM functions/events from native code?

I am wondering if it is possible for native functions to signal Java functions/events?

Basically I think I will run some C++ code on a separate thread and do stuff like handling SIP and then for example if the native thread detects a开发者_C百科n incomming call, being able to signal the JVM somehow. I am not sure how communication like this is done in JNI.

Any ideas?

There are several good articles around, like this one. Here's a Developer Works article that looks good too.