TimerThread is broken

TimerThread doesn't use as much locking as it should: it gets a thread from a list, without locking, and then proceeds to set some fields on it. That "works" except that the TimerThread doesn't stop for GC, so it's possible that a GC occurs in between it getting the thread and setting the field.

The simplest solution is to use more locking (acctLock would work), but there are probably other, better, ways.