3 ms·
Interesting. I wonder how much this lookup check adds to every app's load time? I may have missed it in the article, but is the lookup run only upon first time
by cyberferret 8y ago
Interesting. I wonder how much this lookup check adds to every app's load time?
I may have missed it in the article, but is the lookup run only upon first time the app is executed, or on every single run instance?
- saagarjha 8y agoIt's done every time app hits a function that requires a workaround. Basically, there are a bunch of calls to _CFAppVersionCheckLessThan sprinkled around Apple's frameworks everywhere. However, the result appears to be cached, so the actual meat of the comparison in the amortized case is a simple lookup.
- jsjohnst 8y ago> I wonder how much this lookup check adds to every app's load time? Based on the IDA disassembly, not much. A few extra CPU instructions has minimal impact generally. > but is the lookup run only upon first time the app is executed, or on every single run instance? It’s done every time the function in question is executed from what I can tell.
- saagarjha 8y ago_CFAppVersionCheckLessThan is called every time, yes, but the result of the check is cached as far as I can tell.