RE: System Wake Lock and BG Sync

Hi Marcos,

Sorry for nobody getting back to you.

My take on this is that a system lock is a better, smaller primitive than a background sync one. Indeed, you could imagine background sync being composed out of something like push notifications that wake up a service worker, that then acquires a system lock to do work. Even if that's not the official "explanation," it might be a good polyfill.

It would also be helpful to consider system lock cases that are not related to background sync. For example, the iOS use case in your linked document says that "On iOS, even if the user turns off the screen, the application continues to run and notifies the when they need to make a turn." I don't know how they implement this, but it seems like it might be via a system lock?

Finally, I'm generally always in support of adding APIs to the web platform that help us achieve native parity, and as you've documented, native platforms do have this ability.

________________________________________
From: Marcos Caceres <marcos@marcosc.com>
Sent: Wednesday, August 06, 2014 10:24
To: www-tag@w3.org
Cc: Dominique Hazaël-Massieux; Ilya Bogdanovich; natasha Rooney; Mounir Lamouri
Subject: System Wake Lock and BG Sync

Hi TAG,

As you know, a few of us have been trying to put together some use cases and requirements for a Wake Lock API [1] for the Web.

As part of that, we've hit an overlap problem between requesting a "system" wake lock - known also as a "cpu lock" on some platforms (i.e., "you can turn off the screen, but continue doing task X in the background.") and the BackgroundSync API [2] that Alex and a others are working on for SWs.

We are going to defer adding the ability to do a "system" lock to the Wake Lock API for now, but it would be great for us to discuss if a "system" lock should exist at all given background sync. As a concrete use case to discuss, FireFox OS makes use of a wake lock To be able to import contacts from FaceBook, which can take a while (and the user may want to turn the screen off and put the phone back in their pocket while that is happening). It seems that FireFox OS's email app also makes use of this functionality.

We would appreciate your thoughts on wether we need a "system" wake lock at all. For record keeping, this is issue #25 in our GH repo [3].

Kind regards,
Marcos

[1] http://w3c-webmob.github.io/wake-lock-use-cases/
[2] https://github.com/slightlyoff/BackgroundSync
[3] https://github.com/w3c-webmob/wake-lock-use-cases/issues/25
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Marcos Caceres

Received on Friday, 15 August 2014 16:42:05 UTC