am 5bd5c25e: Merge "Docs: Migration, rewrite of Doze/App Standby doc from M...

page.title=Power-Saving Optimizations

page.keywords=preview,sdk,compatibility

sdk.platform.apiLevel=MNC

@jd:body

<div id="qv-wrapper">

<div id="qv">

<h2>In this document</h2>

<ol  class="hide-nested">

    <li><a href="#behavior-doze">Doze</a></li>

    <li><a href="#behavior-app-standby">App Standby</a></li>

</ol>

<h2>API Differences</h2>

<ol>

<li><a href="{@docRoot}preview/download.html">API level 22 to M Preview &raquo;</a> </li>

</ol>

<h2>See Also</h2>

<ol>

<li><a href="{@docRoot}preview/api-overview.html">M Developer Preview API Overview</a> </li>

</ol>

</div>

</div>

<p>Android M Preview helps prolong battery life by introducing new power-saving optimizations:

<em>Doze</em> mode improves the sleep efficiency of idle devices. <em>App Standby</em> prevents apps

from eating up power while idle.</p>

<h2 id="behavior-doze">Doze</h2>

<p>If a user leaves a device unplugged and stationary for a period of time, with the screen off,

the device enters Doze mode. Doze attempts to keep the system in a sleep state as long as the

device remains undisturbed. In this mode, devices periodically resume normal operations for brief periods of time so that the system can perform app syncing and any other pending operations.</p>

<p>The following restrictions apply to your apps while in Doze:</p>

<ul>

<li>Network access is disabled, unless your app receives a high-priority

<a href="https://developers.google.com/cloud-messaging/" class="external-link">

Google Cloud Messaging</a> tickle.</li>

<li>The system ignores <a href="{@docRoot}reference/android/os/PowerManager.WakeLock.html">

Wake locks</a>.</li>

<li>Alarms scheduled using the {@link android.app.AlarmManager} class are deferred, unless you have

exempted them using the

{@link android.app.AlarmManager#setAndAllowWhileIdle setAndAllowWhileIdle()} method.</li>

<li>The system does not perform Wi-Fi scans.</li>

<li>The system does not permit syncs or jobs for your sync adapters.</li>

<li>The system does not allow {@link android.app.job.JobScheduler} to run.</li>

</ul>

</p>

<p>When the device exits Doze mode, it executes any jobs and syncs that are pending.</p>

<h3>Testing apps with Doze</h3>

<p>You can test Doze mode by connecting your development host to a device running the M Preview,

and calling the following commands:

</p>

<pre class="no-prettyprint">

$ adb shell dumpsys battery unplug

$ adb shell dumpsys deviceidle step

$ adb shell dumpsys deviceidle -h

</pre>

<p class="note"><strong>Note</strong>: As of M Preview 3 release,

<a href="https://developers.google.com/cloud-messaging/" class="external-link">

Google Cloud Messaging</a> (GCM) lets you designate

<a href="https://developers.google.com/cloud-messaging/downstream#setting-the-priority-of-a-message">

high-priority messages</a>. If your app receives a high-priority GCM message</a>, the system grants

brief network access even when the device is dozing.

</p>

<p>See the

<a href="{@docRoot}preview/testing/guide.html#doze-standby">Testing Guide</a> for tips on how

to test Doze in your apps. </p>

<h2 id="behavior-app-standby">App Standby</h2>

<p>App Standby allows the system to determine that an app is idle when the user is not actively

using it. The system makes this determination when the user does not touch the app for a certain

period of time, and none of the following conditions applies:</p>

<ul>

<li>The user explicitly launches the app.</li>

<li>The app has a process currently in the foreground (either as an activity or foreground service,

or in use by another activity or foreground service).</li>

<li>The app generates a notification that users see on the lock screen or in the

notification tray.</li>

<li>The user explicitly asks for the app to be exempt from optimizations,

via the Settings app.</li>

</ul>

<p>When the user plugs the device into a power supply, the system releases apps from the standby

state, allowing them to freely access the network and to execute any pending jobs and syncs. If the

device is idle for long periods of time, the system allows idle apps network access around once a

day.</p>

<h3>Testing apps with App Standby</h3>

<p>You can test App Standby by connecting your development host to a device running the M Preview,

and calling the following commands:

</p>

<pre class="no-prettyprint">

$ adb shell dumpsys battery unplug

$ adb shell am set-idle <packageName> true

$ adb shell am set-idle <packageName> false

$ adb shell am get-idle <packageName>

</pre>

<p class="note"><strong>Note</strong>:

As of M Preview 3 release,

<a href="https://developers.google.com/cloud-messaging/" class="external-link">

Google Cloud Messaging</a> (GCM) lets you

designate

<a href="https://developers.google.com/cloud-messaging/downstream#setting-the-priority-of-a-message">

high-priority messages</a>. If your app receives high-priority GCM messages, the system grants

brief network access even when the app is idle.

</p>

<p>See the

<a href="{@docRoot}preview/testing/guide.html#doze-standby">Testing Guide</a> for tips on how

to test App Standby in your apps. </p>

      zh-cn-lang="自动备份应用"

      zh-tw-lang="針對應用程式進行自動備份">

          Auto Backup for Apps</a></li>

        <li><a href="<?cs var:toroot ?>preview/features/power-mgmt.html"

      es-lang="Optimizaciones de ahorro de energía"

      ja-lang="省電力の最適化"

      ko-lang="절전 최적화"

      pt-br-lang="Otimizações de economia de energia"

      ru-lang="Оптимизация экономии энергии"

      zh-cn-lang="节能优化"

      zh-tw-lang="省電最佳化">

      Power-Saving Optimizations</a></li>

      </ul>

  </li>