Java HotSpot Virtual Machine

I am preparing a c++ dll that will be used by a peer group. This c++ dll is invoking a jvm inside via jni.

Now, I do not know how the peer group will use my c++ dll objects. i.e. they can be used in multiple threads. Currently, I am caching the jni implementation (jobject, jclass, jenv, jvm) within each c++ dll object.

Since the jenv needs to be different for each thread, I am thinking of preparing a map that has a threadID---jenv mapping. So, each object before invoking any of its methods can get the appropriate jenv based on the thread it is in.

I know that this is more of a design question, but this seems to be a common problem and l welcome all the "pearls of wisdom" from our jni gurus.

thanks in advance
Hitendra Gupta