Understanding JVM's "Attach Listener" thread

Question

When I use

jstack -l pid

to see the thread's dump info, I get result as follow:

"Attach Listener" daemon prio=10 tid=0x01e4a800 nid=0x109c waiting on condition
[0x00000000]
   java.lang.Thread.State: RUNNABLE

   Locked ownable synchronizers:
        - None

My questions are as follow:

1. What's the function of "Attach Listener" thread?
2. When does this thread be created? Where? I can't find it.

Thank you very much.

Answer 1

See here http://openjdk.java.net/groups/hotspot/docs/Serviceability.html

Find "Dynamic Attach”

Dynamic attach has an attach listener thread in the target JVM. This is a thread that is started when the first attach request occurs.