Type:
Class
Constants:
Default
:
th->thgroup
The default ThreadGroup created when Ruby starts; all Threads belong to it by default.
ThreadGroup provides a means of keeping track of a number of
threads as a group. A Thread can belong to only one
ThreadGroup at a time; adding a thread to a new group will
remove it from any previous group.
Newly created threads belong to the same group as the thread from which they were created.