do not use job after it is queued on event_q
    
    When a job is queued on the event_q using event_q_notify, once
    the job is enqueued, it should not be referenced again.  The
    event_q thread may wake up immediately and process the job, which
    may be a job deletion event, which will destroy the job.  Due to
    thread scheduling, this may happen before the call to
    event_q_wake if another thread has already woken up the event_q
    thread.