Memory leak in wiregrid encoder agent

[BrianJKoopman]

It seems under certain conditions there is a memory leak in the wiregrid encoder agent. We ran into this on satp1 last night:

Right around that time the logs go from filled with "Received IRIG timeout packet" to "while calling from thread":

2024-10-24 15:39:08.363 2024-10-24T15:39:08+0000 Recieved IRIG timeout packet.
2024-10-24 15:39:18.819 2024-10-24T15:39:18+0000 Recieved IRIG timeout packet.
2024-10-24 15:39:28.838 2024-10-24T15:39:28+0000 Recieved IRIG timeout packet.
2024-10-24 15:39:38.862 2024-10-24T15:39:38+0000 Recieved IRIG timeout packet.
2024-10-24 15:39:48.894 2024-10-24T15:39:48+0000 Recieved IRIG timeout packet.
2024-10-24 15:39:58.904 2024-10-24T15:39:58+0000 Recieved IRIG timeout packet.
2024-10-24 15:40:08.922 2024-10-24T15:40:08+0000 Recieved IRIG timeout packet.
2024-10-24 15:40:21.938 2024-10-24T15:40:21+0000 while calling from thread
2024-10-24 15:40:21.939 2024-10-24T15:40:21+0000 while calling from thread
2024-10-24 15:40:21.940 2024-10-24T15:40:21+0000 Recieved IRIG timeout packet.
2024-10-24 15:40:21.940 2024-10-24T15:40:21+0000 while calling from thread
2024-10-24 15:40:21.941 2024-10-24T15:40:21+0000 while calling from thread
2024-10-24 15:40:21.942 2024-10-24T15:40:21+0000 while calling from thread
2024-10-24 15:40:21.944 2024-10-24T15:40:21+0000 while calling from thread
2024-10-24 15:40:21.944 2024-10-24T15:40:21+0000 while calling from thread
2024-10-24 15:40:21.946 2024-10-24T15:40:21+0000 while calling from thread

I'm not sure what's generating that "while calling from thread" message. I don't see anything with that string in it in the agent or Encoder beaglebone code, but maybe I'm missing something.

My immediate suspicion is in the nested while True: loops in grab_and_parse_data(). That's a good place to start for a deeper investigation. (And this should probably be improved, even if it doesn't end up being the problem.)