Posted by Mayank Jain – Product Supervisor, and Yasser Dbeis – Software program Engineer; Android Studio
Android builders have been telling us they’re in search of instruments to assist optimize energy consumption for various gadgets on Android.
The brand new Energy Profiler in Android Studio helps Android builders by exhibiting energy consumption occurring on gadgets because the app is getting used. Understanding energy consumption throughout Android gadgets might help Android builders establish and repair energy consumption points of their apps. They will run A/B exams to match 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 gadget, which suggests an improved consumer expertise on Android.
This energy consumption information is made accessible by means of the On Gadget Energy Monitor (ODPM) on Pixel 6+ gadgets, segmented by every sub-system known as “Energy Rails”. See Profileable energy rails for an inventory of supported sub-systems.
The Energy Profiler might help app builders detect issues in a number of areas:
- Detecting unoptimized code that’s utilizing extra energy than needed.
- Discovering background duties which might be inflicting pointless CPU utilization.
- Figuring out wakelocks which might be holding the gadget awake when they aren’t wanted.
As soon as an influence consumption challenge has been recognized, the Energy Profiler can be utilized when testing totally different hypotheses to know why the app may very well be consuming extreme energy. For instance, if the difficulty is brought on by background duties, the developer can attempt to cease the duties from operating unnecessarily or for longer durations. And if the difficulty is brought on by wakelocks, the developer can attempt to launch the wakelocks when the useful resource just isn’t in use or use them extra judiciously. Then evaluate the ability consumption earlier than/after the change utilizing the Energy Profiler.
On this weblog publish, we showcase a method 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 characteristic – 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 may have an app by means of which customers should buy their favourite motion pictures.
As your app turns into well-liked and is utilized by extra customers, you notice that a top quality 4K video takes very lengthy to load each time the app is began. Due to its massive measurement, you wish to perceive its influence on energy consumption on the gadget.
Initially, this video was in 4K high quality in the most effective of intentions, in order to showcase the very best film highlights to your prospects.
This makes you suppose…
- Do you actually need 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 if you happen to 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 situation 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 characteristic 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 connect the CPU profiler to it and set off a system hint (the place the Energy Profiler might 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 connect the CPU profiler to it.
Observe on precision
The next instance situations use your entire app startup for estimating the ability consumption for this weblog’s objective. Nevertheless you should utilize extra superior methods to have even greater precision in getting energy readings. Some methods to strive 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 situation, 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 situation A a number of occasions 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 situation 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 evaluate and distinction how this energy consumption adjustments in Situation B
Situation B
On this situation, 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 situation B a number of occasions 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 whole energy consumed by WLAN, CPU Little, CPU Huge 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 supplies 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 residence display not solely reduces energy consumption by 45%, additionally reduces the required community bandwidth and might probably additionally enhance the thermal efficiency of the gadgets.
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 consumer faucet.
- Loading a picture initially and solely load the video after the display has absolutely rendered (delayed loading).
The general energy consumption numbers introduced within the above A/B check situation 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 on the market in Android Studio Hedgehog onwards. To know extra, please head over to the official documentation.
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