An initial thread, which is created when the job starts, can never
be deleted or ended. However, sometimes it is necessary to end a secondary
thread so that a job can continue to run. Be aware of the thread you intend
to end because the job it runs within might not be able to complete without
that thread's work.
Important: Ending threads should not be a part of your
daily work management routine. Ending a thread is more serious than ending
a job because the work in other threads might or might not stop. When you
end a job, all the work stops. However, when you end a thread, only a portion
of the work stops. Other threads might or might not continue to run. If they
continue running without the thread that you end, they might produce undesirable
results.
To delete or end a secondary thread, you must have service
(*SERVICE) special authority or Thread Control authority.