Question

Can we use jmethodID intialized on one thread in another thread ? I asked this because my jvm is crashing when i run the jni program,in which i have initialized jmethodID on one thread and using it in another thread. I was thinking if this could be a reason.

I have kept jmethodID as a global varibale by declaring at the top. Then in one of the call I initialize it and in the subsequent calls i attempt to reuse it.

Answer 1

Quoting from the JNI Specification:

A field or method ID does not prevent the VM from unloading the class
from which the ID has been derived. After the class is unloaded, the
method or field ID becomes invalid. The native code, therefore, must
make sure to:

keep a live reference to the underlying class, or

recompute the method or field ID

if it intends to use a method or field ID for an extended period of
time.