3 ms·

Currently dealing with an intermittent concurrency related bug. It's horrible.

• lectrick 11y ago
  This is why i want to avoid mutable data as much as possible
• Gibbon1 11y ago
  Have one that took six months to find. The database person spent a month trying to figure out why there were entries with odd dates. Like one or two a month out of a few hundred thousand. Eventually figured out it wasn't his fault. His end was getting an occasional packet with a good crc and odd data. Most of the time the parser would kick those out. But a few were well formed enough to go through. I chased it down eventually to a documentation error in the datasheet for the radio transceiver we were using. The datasheet very clearly stated that when a packet came in with a bad crc... nothing would happen. No end of packet interrupt. So I had to use a timer to detect a bad crc. (Okay whatever, I mean I hate those guys, but I've seen worse) Turns out when the radio received a packet with a wrong/bad crc the radio silently reset the receiver and started waiting for a new packet. If a the radio received a packet before the timeout hammer came down then the driver would think the previously received packet was 'good' Opps. Was interesting because the symptom appeared at the farthest end of the system the tool graphing data for the customer and was caused by something at the other end. The error could have been literally anywhere in our system.