How to interpret a Java thread that is RUNNABLE but without a stack trace?

Question

I am debugging an outdated Java application, and the stream dump (obtained using jstack ) contains the following elements:

 "Thread-8" prio=10 tid=0x0000000055f2c800 nid=0x49bf runnable [0x0000000000000000] java.lang.Thread.State: RUNNABLE 

What is it. No stack trace.

What's going on here? How to find Java executable code in this thread?

Answer 1

The thread does not execute (or does not execute) Java code. It handles tasks not implemented in Java that are not directly requested by any Java call. For example, if the corresponding OS thread just caught a signal.