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A Collection of iOS App Launch Performance Optimization ResourcesiOS 应用启动性能优化资料汇总

· Performance & internals

Translated from Chinese — .

On this page

I collect good resources here whenever I find them. Updated continuously, last updated August 19, 2018

WWDC

  1. Optimizing App Startup Time

    Must-watch official material, from the low level to the high level https://developer.apple.com/videos/play/wwdc2016/406/

  2. App Startup Time: Past, Present, and Future

    Optimization at the dyld level https://developer.apple.com/videos/play/wwdc2017/413/

  3. Optimizing I/O for Performance and Battery Life

    IO is an important factor affecting launch performance https://developer.apple.com/videos/play/wwdc2016/719/

  4. Practical Approaches to Great App Performance

    Solving performance problems step by step live on stage https://developer.apple.com/videos/play/wwdc2018/407/

  5. Using Time Profiler in Instruments

    Time Profiler is an essential helper https://developer.apple.com/videos/play/wwdc2016/418/

  6. High Performance Auto Layout

    If your app’s home page uses AutoLayout, it seems it won’t be a problem from now on https://developer.apple.com/videos/play/wwdc2018/220/

  7. Core Image: Performance, Prototyping, and Python

    The home page of course also has lots of images, so learn about Core Image https://developer.apple.com/videos/play/wwdc2018/719/

Articles

The following articles are merely a collection; they are each one person’s opinion. Don’t believe them all, and don’t oppose them all — each has its reasoning. Just learn the line of thinking.

  1. Jike Tech Team: iOS app launch speed research and practice

    Link https://zhuanlan.zhihu.com/p/38183046?from=1086193010&wm=3333_2001&weiboauthoruid=1690182120 Learn the line of thinking.

  2. Measuring the impact of iOS Dynamic Frameworks on app launch time

    https://www.jianshu.com/p/3263009e9228 Tests on dynamic libraries. The takeaway: try not to load dynamic libraries during the launch process.

  3. Optimizing Facebook for iOS start time

    https://code.fb.com/ios/optimizing-facebook-for-ios-start-time/ Facebook’s approach. Even though Facebook’s launch is very slow.

  4. Bugly: iOS App Launch Performance Optimization

    https://mp.weixin.qq.com/s/Kf3EbDIUuf0aWVT-UCEmbA This article reveals a very powerful idea at the end. Strongly recommend reading the end of the article carefully.

  5. Toutiao iOS Client Launch Speed Optimization

    https://techblog.toutiao.com/2017/01/17/iosspeed/ There’s a lot of info at the start of the article, but reducing the amount of code seems hard to actually pull off.

  6. How to precisely measure the launch time of an iOS App

    https://www.jianshu.com/p/c14987eee107 The article’s line of thinking is worth referencing.

  7. Optimizing App Startup Time

    http://yulingtianxia.com/blog/2016/10/30/Optimizing-App-Startup-Time/ Mainly notes on WWDC, but still very powerful. “Nan Xiaoyu in the south, Bei Ziqi in the north.” This article was written by Nan Xiaoyu.

  8. Taobao iOS Performance Optimization Exploration

    https://github.com/izhangxb/GMTC/blob/master/%E5%85%A8%E7%90%83%E7%A7%BB%E5%8A%A8%E6%8A%80%E6%9C%AF%E5%A4%A7%E4%BC%9AGMTC%202017%20PPT/%E6%89%8B%E6%B7%98iOS%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96%E6%8E%A2%E7%B4%A2%20.pdf This is a tech talk by a Taobao expert at GMTC 2017, worth referencing.

  9. iOS App Launch Performance Optimization (1) - premain

    https://xnu.app/2018/05/26/ios-app-launch-performance-part1/ Just the line of thinking for the pre-main stage. The author said there would be follow-up articles, but it’s been quiet for a long time — who knows what he’s up to.

  10. Hook all +load methods

    A method to hook objective c +load https://xnu.app/2017/01/06/a-method-of-hook-objective-c-load/

    Hook all +load methods (including Categories)

https://xnu.app/2018/08/19/ios-hook-really-all-load/

  1. A method to hook C++ static initializers

    https://xnu.app/2017/02/06/a-method-of-hook-static-initializers/ The hook method in this article is quite possibly my own original creation. Strongly recommended. The Taobao talk also mentioned this method.

  2. A method to delay premain code

    https://xnu.app/2017/03/06/a-method-of-delay-premain-code/ A line of thinking discovered by studying a special section unique to Facebook’s App (refer to the article https://xnu.app/2016/08/20/facebook-explore-section-fbinjectable/ ).

Tools

  1. TimeProfiler

    Everyone knows what this is.

  2. AppleTrace

    https://github.com/everettjf/AppleTrace Uses HookZz to hook objc_msgSend; there’s significant performance overhead, but you can know the approximate proportion of time cost based on relative ratios. It also manually defines start and end points to generate chrome tracing.

  3. DTrace

    Can only be used on the simulator. For usage, refer to this book: Advanced Apple Debugging & Reverse Engineering https://store.raywenderlich.com/products/advanced-apple-debugging-and-reverse-engineering

  4. Xcode Environment Variables

    DYLD_PRINT_STATISTIC and other similar environment variables https://developer.apple.com/library/archive/documentation/DeveloperTools/Conceptual/DynamicLibraries/100-Articles/LoggingDynamicLoaderEvents.html

Code

  1. FastImageCache

    https://github.com/path/FastImageCache Optimizes image loading speed. Trading space for time.

Niche Antiques

  1. Code Size Performance Guidelines

    https://developer.apple.com/library/archive/documentation/Performance/Conceptual/CodeFootprint/Articles/MachOOverview.html The idea at the very bottom of the page is good, but the article is from the gcc era. Is there a clang-era counterpart? Improving Locality of Reference https://developer.apple.com/library/archive/documentation/Performance/Conceptual/CodeFootprint/Articles/ImprovingLocality.html#//apple_ref/doc/uid/20001862-CJBJFIDD

Books

  1. Pro iOS Apps Performance Optimization

    Seems rather old, for reference only.

  2. iOS and macOS Performance Tuning

    Very detailed, I’m reading it now. There’s a Chinese translation.

  3. High Performance iOS Apps

    There’s a Chinese translation.

Summary

I’ve read all the articles above, or am at least reading them. Summarized here to help everyone optimize launch performance.

文章目录

发现好资料就整理到这里，随时更新，最后一次更新2018年8月19日

WWDC

  1. Optimizing App Startup Time

    必看官方资料，从底层到上层 https://developer.apple.com/videos/play/wwdc2016/406/

  2. App Startup Time: Past, Present, and Future

    dyld层面的优化 https://developer.apple.com/videos/play/wwdc2017/413/

  3. Optimizing I/O for Performance and Battery Life

    IO是启动性能的重要影响部分 https://developer.apple.com/videos/play/wwdc2016/719/

  4. Practical Approaches to Great App Performance

    现场一步一步解决性能问题 https://developer.apple.com/videos/play/wwdc2018/407/

  5. Using Time Profiler in Instruments

    TimeProfiler是必备好帮手 https://developer.apple.com/videos/play/wwdc2016/418/

  6. High Performance Auto Layout

    App首页如果是AutoLayout的，那么以后看来不是问题了 https://developer.apple.com/videos/play/wwdc2018/220/

  7. Core Image: Performance, Prototyping, and Python

    首页当然也有大量的图片，了解Core Image https://developer.apple.com/videos/play/wwdc2018/719/

文章

以下文章仅仅是收集，各家之谈，不要全信，也不要反对，各有道理，学习思路即可。

  1. 即刻技术团队：iOS app 启动速度研究实践

    地址 https://zhuanlan.zhihu.com/p/38183046?from=1086193010&wm=3333_2001&weiboauthoruid=1690182120 学习思路。

  2. iOS Dynamic Framework 对App启动时间影响实测

    https://www.jianshu.com/p/3263009e9228 动态库的测试。可知：启动过程中尽量不要加载动态库了。

  3. Optimizing Facebook for iOS start time

    https://code.fb.com/ios/optimizing-facebook-for-ios-start-time/ Facebook的思路。虽然Facebook的启动很慢。

  4. Bugly: iOS App 启动性能优化

    https://mp.weixin.qq.com/s/Kf3EbDIUuf0aWVT-UCEmbA 这篇文章最后透露了一个很给力的思路。强烈推荐仔细看文章最后。

  5. 今日头条iOS客户端启动速度优化

    https://techblog.toutiao.com/2017/01/17/iosspeed/ 文章开头的信息很多，但减少代码量，貌似很难行得通。

  6. 如何精确度量 iOS App 的启动时间

    https://www.jianshu.com/p/c14987eee107 文章的思路可参考。

  7. 优化 App 的启动时间

    http://yulingtianxia.com/blog/2016/10/30/Optimizing-App-Startup-Time/ 主要是对WWDC的笔记，但仍然很给力。南萧玉，北子棋。这篇文章就是南萧玉所作。

  8. 手淘iOS性能优化探索

    https://github.com/izhangxb/GMTC/blob/master/%E5%85%A8%E7%90%83%E7%A7%BB%E5%8A%A8%E6%8A%80%E6%9C%AF%E5%A4%A7%E4%BC%9AGMTC%202017%20PPT/%E6%89%8B%E6%B7%98iOS%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96%E6%8E%A2%E7%B4%A2%20.pdf 这是GMTC 2017手机淘宝专家的技术分享，可以参考。

  9. iOS应用启动性能优化(1)-premain

    https://xnu.app/2018/05/26/ios-app-launch-performance-part1/ 仅仅是pre-main阶段的思路。作者说有后续的文章，但很久没动静了，不知道在搞什么。

  10. Hook所有+load方法

    一种 hook objective c +load 的方法 https://xnu.app/2017/01/06/a-method-of-hook-objective-c-load/

    Hook所有+load方法（包括Category）

https://xnu.app/2018/08/19/ios-hook-really-all-load/

  1. 一种 hook C++ static initializers 的方法

    https://xnu.app/2017/02/06/a-method-of-hook-static-initializers/ 这篇文章的hook方法，有较大的可能是我首创，强烈推荐。手淘的分享中也提了这个方法。

  2. 一种延迟 premain code 的方法

    https://xnu.app/2017/03/06/a-method-of-delay-premain-code/ 通过学习Facebook的App中特有的section（参考文章 https://xnu.app/2016/08/20/facebook-explore-section-fbinjectable/ ），发现的一种思路。

工具

  1. TimeProfiler

    都知道是啥。

  2. AppleTrace

    https://github.com/everettjf/AppleTrace 使用 HookZz hook了objc_msgSend，会有较大性能损耗，但可根据相对比例来知道大概的耗时占比。另外也手动定义开始结尾生成chrome tracing。

  3. DTrace

    只能用于模拟器。使用方法可参考这本书：Advanced Apple Debugging & Reverse Engineering https://store.raywenderlich.com/products/advanced-apple-debugging-and-reverse-engineering

  4. Xcode 环境变量

    DYLD_PRINT_STATISTIC 及其他类似环境变量 https://developer.apple.com/library/archive/documentation/DeveloperTools/Conceptual/DynamicLibraries/100-Articles/LoggingDynamicLoaderEvents.html

代码

  1. FastImageCache

    https://github.com/path/FastImageCache 优化图片加载的速度。空间换时间。

偏门古董

  1. Code Size Performance Guidelines

    https://developer.apple.com/library/archive/documentation/Performance/Conceptual/CodeFootprint/Articles/MachOOverview.html 页面最下面提出的思路很好，但文章是gcc时代的了。有没有clang时代对应的呢。 Improving Locality of Reference https://developer.apple.com/library/archive/documentation/Performance/Conceptual/CodeFootprint/Articles/ImprovingLocality.html#//apple_ref/doc/uid/20001862-CJBJFIDD

书籍

  1. Pro iOS Apps Performance Optimization

    貌似比较古老，仅参考。

  2. iOS and macOS Performance Tuning

    很细致，我正在看。有中文翻译版。

  3. High Performance iOS Apps

    有中文翻译版。

总结

上面的文章我都看过，或者至少是正在看，总结下来，辅助大家优化启动性能。