Boffins tell sleep-talking Android apps to SHUT UP

Too many Android apps are battery hogs when the screen is off, so researchers at Purdue University have released to a tool to shut them up.

As the university explains here, badly-behaved apps can drain nearly 30 per cent of an Android phone's charge when the user thinks it's sleeping.

“Out of the 45.9 per cent of daily battery drain where the screen is off, 28.9 per cent is due to apps that frequently wake up and run in the background”, the university's release claims.

Enter HUSH, which the Purdue crew have released at GitHub and which they reckon can save nearly half of that wasted energy consumption.

The problem, according to electrical engineering professor Y Charlie Hu, is that app programmers make mistakes using the Android wakelocks. As a result, an app might wake up to do something useful while the phone's idle, but afterwards, it fails to let the phone go back to sleep.

In dealing with this, however, Hu's group has also tried to take into account user behaviour. For example, a heavy Facebook user won't thank the app if every time they wake the phone up, they have to wait for the Facebook app to catch up on a bunch of status updates.

The release says HUSH “dynamically identifies app background activities that are not useful to the user experience on a per-app basis and suppresses such background app activities during screen-off to reduce the battery drain.”

The current study, presented last week at the ACM's MobiCom 2015 conference, was a follow-up to a 2012 study into wakelock bugs. The previous study looked at the code of individual apps, while the update checked out the behaviour of phones “in the wild”.

To identify the prevalence of bad wakelock behaviour, the Purdue researchers worked with Intel (which, with the National Science Foundation, funded the research) and Mobile Enerlytics to study the behaviour of 2,000 Samsung Galaxy S3 and S4 phones in 61 countries. ®