Created by: Carrotman42
If an alarm is received by a thread after it has blocked in check_wait_at_safe_spot but before the detaching thread sends the SUSPEND_SIGNAL, it is possible the fcache_unit_areas lock is being held in record_pending_signal when the SUSPEND_SIGNAL is received. Since the receiving thread was already marked as waiting at a safe spot, we synchronize with the thread and detach it, and the fcache_unit_areas lock is never unlocked.
Issue: #2270 (closed)