Apple’s SSL Metrics Is Hanging My App
We’ve been getting some reports that NetNewsWire for Mac will hang sometimes. A sample will report something like this:
Dispatch Thread Hard Limit: 512 reached in 1580 of 1580 samples -- too many dispatch threads blocked in synchronous operations
And there will be hundreds of threads labelled
Here’s an example, with sample report, on our bug tracker.
What I think is happening: these Apple metrics reports are happening once per download per feed. So, if you have 1,000 feeds, then there are 1,000 metrics reports for a given download session. If those reports don’t complete quickly enough, then you get this thread explosion.
So… I could slow down our feed downloader so that this is less likely to happen, so that the metrics reports don’t back up so much. I don’t really want to slow down refreshing, though, but I may have no choice.
Luckily, most people don’t have the number of feeds it would take to trigger this. But, still, that’s not good enough — NetNewsWire should never hang for any user.