persist应用

最新推荐文章于 2025-05-25 17:14:22 发布

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最新推荐文章于 2025-05-25 17:14:22 发布

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分类专栏： Android

本文链接：https://blog.youkuaiyun.com/snail_coder/article/details/51628163

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1.什么是persist应用？

在AndroidManifest.xml中的applicationtag中定义：android:persistent="true"

在解析此应用时，给它增加一个flag：ApplicationInfo.FLAG_PERSISTENT

// PackageParser.java parseBaseApplication

if ((flags&PARSE_IS_SYSTEM) != 0) {
    if (sa.getBoolean(
            com.android.internal.R.styleable.AndroidManifestApplication_persistent,
            false)) {
        ai.flags |= ApplicationInfo.FLAG_PERSISTENT;
    }
}

// ApplicationInfo.java
/**
 * Value for {@link #flags}: set to true if this application is persistent.
 * Comes from {@link android.R.styleable#AndroidManifestApplication_persistent
 * android:persistent} of the &lt;application&gt; tag.
 */
public static final int FLAG_PERSISTENT = 1<<3;

从注释可知，这代表此应用为persist app。

2.如何查询persit应用以及谁会去查询？

PackageManagerService.java提供了方法public List<ApplicationInfo> getPersistentApplications(int flags)可供查询.

依据就是查看哪个Application包含这个前面提到的flag：ApplicationInfo.FLAG_PERSISTENT

谁会查询或关注这点？

AMS会关注，在它的systemReady方法中调用，目的就是在system ready后启动这些persist应用。所以，他们会由系统自动启动，在BOOT_COMPLETED之前。

具体流程如下：

startOtherServices() //SystemServer.java
systemReady(final Runnable goingCallback) // ActivityManagerService.java
addAppLocked(info, false, null /* ABI override */);
startProcessLocked(app, "added application", app.processName, abiOverride, null /* entryPoint */, null /* entryPointArgs */);
Process.start(...)

3.log信息

// system ready
06-05 21:14:29.620509 763 763 I SystemServer: Making services ready
06-05 21:14:29.640944 763 763 I ActivityManager: Start proc com.android.systemui for service com.android.systemui/.SystemUIService: pid=864 uid=10022 gids={50022, 1028, 1015, 1035, 3002, 3001, 3003, 1007}
06-05 21:14:29.641193 763 817 I MountService: handleSystemReady
06-05 21:14:29.943741 763 763 D UsbDeviceManager: systemReady
06-05 21:14:29.949129 763 763 D AppWidgetService: systemRunning
06-05 21:14:29.949196 763 763 I AppWidgetServiceImpl: u=0: systemReady
06-05 21:14:29.979798 763 763 V WallpaperManagerService: systemReady
06-05 21:14:30.069004 763 763 I RecoveryManagerService: systemReady()
// start persist app
06-05 21:14:30.243268 763 763 I ActivityManager: Start proc com.android.phone for added application com.android.phone: pid=1007 uid=1001 gids={41001, 3002, 3001, 3003, 1028, 1015, 1013, 1006, 1004, 2002, 1023}
06-05 21:14:30.262986 763 763 I ActivityManager: Start proc com.mediatek.voicecommand for added application com.mediatek.voicecommand: pid=1019 uid=10084 gids={50084, 1028, 1015, 1013, 1006}
06-05 21:14:30.273884 763 763 I ActivityManager: Start proc com.mediatek.bluetooth for added application com.mediatek.bluetooth: pid=1033 uid=1002 gids={41002, 3003, 3002, 3001, 1028, 1015, 3005, 1016, 3008, 1023, 1035}
06-05 21:14:30.322054 763 763 I ActivityManager: Start proc com.mediatek.voiceextension for added application com.mediatek.voiceextension: pid=1047 uid=1000 gids={41000, 1007, 1028, 1015, 3005, 3003, 3006, 1023, 3002, 3001}
06-05 21:14:30.416317 763 763 I ActivityManager: Start proc android.process.acore for added application android.process.acore: pid=1125 uid=10008 gids={50008, 3003, 1028, 1015}
06-05 21:14:30.434718 763 763 I ActivityManager: Start proc com.android.incallui for added application com.android.incallui: pid=1139 uid=10049 gids={50049, 3003, 1028, 1015}
// BOOT_COMPLETED
06-05 21:14:33.021543 763 1046 V ActivityManager: Broadcast: Intent { act=android.intent.action.BOOT_COMPLETED flg=0x8000010 (has extras) } ordered=true userid=0 callerApp=null