5 ms·
Run some lists with images on them on iPhone 5. Anecdotal, and I am sure you can dig into metal to improve performance, but out of the box, it's kinda poor. I s
by seivan 11y ago
Run some lists with images on them on iPhone 5. Anecdotal, and I am sure you can dig into metal to improve performance, but out of the box, it's kinda poor. I still like React and I'm hopeful React-Native will improve.
- mwcampbell 11y agoThanks. I wonder how much of that is due to the fact that JavaScriptCore can't use JIT compilation when running in an iOS application other than Safari.
- andrewjl 11y agoAs of iOS 8 that's no longer the case. JSC JIT compilation can be used in native apps. (It's also used by WKWebView.) http://trac.webkit.org/wiki/JavaScriptCore http://trac.webkit.org/wiki/JavaScriptCore "JavaScriptCore is an optimizing virtual machine. JavaScriptCore consists of the following building blocks: lexer, parser, start-up interpreter (LLInt), baseline JIT, a low-latency optimizing JIT (DFG), and a high-throughput optimizing JIT (FTL)."
- DerekL 11y agoApps can use JavaScriptCore, and JavaScriptCore can use JIT, but these can't happen together, because third-party apps aren't permitted to execute writeable memory. http://stackoverflow.com/questions/22281265/is-javascriptcore-framework-on-ios-7-using-jit-compilation http://stackoverflow.com/questions/22281265/is-javascriptcor...
- andrewjl 11y agoThis is good to know. Looks like the only way to make use of JIT (by someone who isn't Apple) is to use a WKWebView to execute the JS.
- ewmailing 11y agoI haven't used React Native, but I've done quite a bit with native bridging with JavaScriptCore and v8. If your performance bottlenecks are crossing the Javascript-to-native boundary, JIT can't help you. And crossing the bridge boundary isn't the cheapest operation.
- mwcampbell 11y agoThat isn't an issue with React Native, which runs JS on its own thread and implements an asynchronous, batched bridge between JS and native.
- zepto 11y agoThis has been false for years.