Issue warning when queue gets too full

[abrahammurciano]

Ideas/To do

• Add parameter queue_warning_size (default 100?)
• Replace Queue with a priority queue
• Issue queue size warnings with higher priority
• Make sure queue size warning is not issued too frequently
  • Maybe only once
  • Maybe once per queue fill up (e.g. once it gets full and a warning is issued, it won't be issued again until queue is half empty then fills up again)
    • bool issue_warning (init True) set to false after warning is issued and set to true when dequeueing and qsize() < queue_warning_size/2
    • when emitting, if qsize() > queue_warning_size and issue_warning, then enqueue log record with higher priority and set issue_warning to False