Every Android user has been there: you’ve just received a beloved OTA update notification so you can get the latest and greatest version of Android, but you’re dreading the long wait for the much despised “Android is Upgrading” dialog that can take up to half an hour to complete! Meanwhile, your phone is useless to you, so you can’t even waste that time on Clash of Clans! Worst of all worlds, right? How about when you’re downloading a new app, and you know that it’s taking a literal year to get through that “Installing” part of the app install process? Luckily there’s a change coming in Android N to solve all your woes.
Prior to Android N, that long upgrade dialog was caused by the Android system compiling each and every app on your device to code that could run through the Android RunTime (ART), which is also what happened on individual app installs. This is called Ahead of Time (AOT) compiling and took a lot of time up front, but has the benefits of significantly faster app startup time and a faster experience all around. Google heard loud and clear that getting the latest version of Android shouldn’t require so much downtime, so in Android N, ART has been changed significantly.
To solve this, Google went back…to the future: Just In Time (JIT) compiling! Starting with N, ART will use a hybrid approach, where the system will compile code as it needs it and keep it around for future use, rather than throwing it away when the app is done like most JIT systems. This means a startup time penalty, but after using the app, the initial launch speed will match (or exceed) the speeds of what you saw in Marshmallow. This also saves a small amount of space on the device, since the system will only compile the parts of the app that are actively being used. In addition to the JIT compiled pieces, the Android system will profile the compiled code to optimize it even further, making your device even more smooth and performant.
So, starting with Android N, you longer have to be afraid of that OTA update notification! Thanks to Android’s new changes to ART, updates and app installs will finish before you know it, and you’ll be back to your Town Hall in no time.