Posted by Mayank Jain – Product Supervisor, and Yasser Dbeis – Software program Engineer; Android Studio
Android builders have been telling us they’re on the lookout for instruments to assist optimize energy consumption for various units on Android.
The brand new Energy Profiler in Android Studio helps Android builders by displaying energy consumption taking place on units because the app is getting used. Understanding energy consumption throughout Android units can assist Android builders establish and repair energy consumption points of their apps. They’ll run A/B checks to check the ability consumption of various algorithms, options and even totally different variations of their app.
Apps that are optimized for decrease energy consumption result in an improved battery and thermal efficiency of the system, which implies an improved person expertise on Android.
This energy consumption information is made out there by means of the On System Energy Monitor (ODPM) on Pixel 6+ units, segmented by every sub-system known as “Energy Rails”. See Profileable energy rails for an inventory of supported sub-systems.
The Energy Profiler can assist app builders detect issues in a number of areas:
- Detecting unoptimized code that’s utilizing extra energy than crucial.
- Discovering background duties which can be inflicting pointless CPU utilization.
- Figuring out wakelocks which can be retaining the system awake when they aren’t wanted.
As soon as an influence consumption subject has been recognized, the Energy Profiler can be utilized when testing totally different hypotheses to know why the app might be consuming extreme energy. For instance, if the problem is attributable to background duties, the developer can attempt to cease the duties from working unnecessarily or for longer intervals. And if the problem is attributable to wakelocks, the developer can attempt to launch the wakelocks when the useful resource is just not in use or use them extra judiciously. Then examine the ability consumption earlier than/after the change utilizing the Energy Profiler.
On this weblog publish, we showcase a way which makes use of A/B testing to know how your app’s energy consumption traits would possibly change with totally different variations of the identical function – and how one can successfully measure them.
An actual-life instance of how the Energy Profiler can be utilized to enhance the battery lifetime of an app.
Let’s assume you’ve got an app by means of which customers should buy their favourite films.
As your app turns into well-liked and is utilized by extra customers, you understand that a top quality 4K video takes very lengthy to load each time the app is began. Due to its giant dimension, you wish to perceive its impression on energy consumption on the system.
Initially, this video was in 4K high quality in the perfect of intentions, in order to showcase the absolute best film highlights to your clients.
This makes you suppose…
- Do you really want a 4K video banner on the house display?
- Does it make sense to load a 4K video over the community each time your app is run?
- How will the ability consumption traits of your app change in the event you substitute the 4K video with one thing of decrease high quality (whereas nonetheless preserving the vivid look & really feel of the video)?
It is a excellent state of affairs to carry out an A/B check for energy consumption
With an A/B check, you possibly can check two barely totally different variations of the video banner function and select the one with the higher energy consumption traits.
Situation A : Run the app with 4K video banner on display & measure energy consumption
Situation B : Run the app with decrease decision video banner on display & measure energy consumption
A/B Check setup
Let’s take a second and arrange our Android Studio profiler to run this A/B check. We have to begin the app and fix the CPU profiler to it and set off a system hint (the place the Energy Profiler can be proven).
Step 1
Create a customized “Run configuration” by clicking the three dot menu > Edit
Step 2
Then choose the “Profiling” tab and make sure that “Begin this recording on startup” and CPU Exercise > System Hint is chosen. Then click on “Apply”.
Now merely run the “Profile app startup profiling with low overhead” everytime you wish to run this app from begin and fix the CPU profiler to it.
Word on precision
The next instance situations use your complete app startup for estimating the ability consumption for this weblog’s function. Nevertheless you should utilize extra superior methods to have even larger precision in getting energy readings. Some methods to attempt are:
- Isolate and measure energy consumption for video playback solely after a faucet occasion on the video participant
- Use the hint markers API to mark the beginning and cease time for energy measurement timeline – after which solely measure energy consumption inside that marked window
Situation A
On this state of affairs, we run the app with 4K video taking part in and measure energy consumption for the primary 30 seconds. We will optionally additionally run the state of affairs A a number of instances and common out the readings. As soon as the System hint is proven in Android Studio, choose the 0-30 second time vary from the timeline choice panel and file as a screenshot for evaluating in opposition to state of affairs B
As you possibly can see, the common energy consumed by WLAN, CPU cores & Reminiscence mixed is about 1,352 mW (milliwatts)
Now let’s examine and distinction how this energy consumption modifications in Situation B
Situation B
On this state of affairs, we run the app with low high quality video taking part in and measure energy consumption for the primary 30 seconds. As earlier than, we are able to additionally optionally run state of affairs B a number of instances and common out the ability consumption readings. Once more, as soon as the System hint is proven in Android Studio, choose the 0-30 second time vary from the timeline choice panel.
The full energy consumed by WLAN, CPU Little, CPU Large and CPU Mid & Reminiscence is about 741 mW (milliwatts)
Conclusion
All else being equal, Situation B (with decrease high quality video) consumed 741 mW energy as in comparison with Situation A (with 4K video) which required 1,352 mW energy.
Situation B (decrease high quality video) took 45% much less energy than Situation A (4K) – whereas the decrease high quality video offers little to no visible distinction in perceived high quality of the app’s display.
Because of this A/B check for energy consumption, you conclude that changing the 4K video with a decrease high quality video on our app’s dwelling display not solely reduces energy consumption by 45%, additionally reduces the required community bandwidth and might doubtlessly additionally enhance the thermal efficiency of the units.
In case your app’s enterprise logic nonetheless requires the 4K video to be proven on the app’s display, you possibly can discover methods like:
- Caching the 4K video throughout subsequent runs of the app.
- Loading video on a person faucet.
- Loading a picture initially and solely load the video after the display has totally rendered (delayed loading).
The general energy consumption numbers offered within the above A/B check state of affairs might sound small, but it surely exhibits the methods that app builders can use to successfully A/B check energy consumption for his or her app’s options utilizing the Energy Profiler in Android Studio.
Subsequent Steps
The brand new Energy Profiler is obtainable in Android Studio Hedgehog onwards. To know extra, please head over to the official documentation.
