app_watchdogd.sh is used to automatically relaunch an Android APP which is killed or crashed.
app_watchdogd.sh can be run in /data/data/com.domain.appname/files/ or /system/xbin/ .
If run app_watchdogd.sh without su -c , even your device is rooted, adb shell cat /proc/APP_WATCHDOG_SH_PID/oom_adj will not be -17 but 0, Android system will kill app_watchdogd.sh process if not smaller than 0 when memory is low, so you need
su -c /data/data/com.domain.appname/files/app_watchdogd.sh &
and this one line command above is obviously better than
/data/data/com.domain.appname/files/app_watchdogd.sh &
manually find APP_WATCHDOG_SH_PID with `ps | grep /system/bin/sh | grep -c poll_sched)`
su -c echo -12 > /proc/APP_WATCHDOG_SH_PID/oom_adj
su -c chmod -r /proc/APP_WATCHDOG_SH_PID/oom_adj
For sure your device
- rooted
- install-supersu
- $1 pkg_or_kill: pkg e.g.
com.domain.appnamemeans enable watchdogd; or justkillmeans disable watchdogd - $2 activity: e.g.
MainActivityif pkg; null if kill - $3 timeout_sec: e.g.
5if pkg; null if kill
adb remount
adb push app_watchdogd.sh system/xbin/
adb shell su -c system/xbin/app_watchdogd.sh com.domain.appname MainActivity 5 &
adb shell su -c system/xbin/app_watchdogd.sh kill
Copy as android/app/src/main/assets/app_watchdogd.sh .
utils.js :
import AndroidShell from '@flyskywhy/react-native-android-shell';
export function enableAppWatchdogd({
shPath = '/system/xbin/app_watchdogd.sh',
pkg,
activity = 'MainActivity',
timeoutSec = 5,
}) {
AndroidShell.executeCommand(
'su -c ' + shPath + ' ' + pkg + ' ' + activity + ' ' + timeoutSec + ' &',
() => {},
);
}
export function disableAppWatchdogd({
shPath = '/system/xbin/app_watchdogd.sh',
callback = () => {},
}) {
AndroidShell.executeCommand('su -c ' + shPath + ' kill', callback);
}
Navigation.js :
if (Platform.OS !== 'web') {
var RNFS = require('react-native-fs');
}
import AndroidShell from '@flyskywhy/react-native-android-shell';
import RNExitApp from 'react-native-exit-app';
import * as utils from '../utils';
const shPath = `${RNFS.DocumentDirectoryPath}/app_watchdogd.sh`;
class Navigation extends Component {
...
componentDidMount() {
this.enableAppWatchdogd();
}
enableAppWatchdogd = async () => {
if (Platform.OS === 'android') {
if (!(await RNFS.exists(shPath))) {
await RNFS.copyFileAssets('app_watchdogd.sh', shPath); // /data/data/com.domain.appname/files/app_watchdogd.sh
}
AndroidShell.executeCommand(
'su -c dumpsys window | grep mCurrentFocus',
(activity) => {
let a = activity
.replace(/\n/, '')
.replace(/^.* .* /, '')
.replace('}', ''); // com.domain.appname/com.domain.appname.MainActivity
let pkg = a.replace(/\/.*/, ''); // com.domain.appname
utils.enableAppWatchdogd({ // if APP exit abnormally (killed or crashed), will be relaunched
shPath,
pkg,
});
},
);
// above have a small bug: after adb install then first launch, pkg could be `com.android.systemui` (from mCurrentFocus)
// below works well if you can `import {applicationId} from 'expo-application'`
// utils.enableAppWatchdogd({ // if APP exit abnormally (killed or crashed), will be relaunched
// shPath,
// pkg: applicationId,
// });
}
};
onBackPress = async () => {
if (USER_PRESS_ANDROID_BACK_KEY_TWICE) {
if (Platform.OS === 'android') {
utils.disableAppWatchdogd({ // if APP exit normally (by user), will disable watchdogd
shPath,
callback: RNExitApp.exitApp,
});
} else {
RNExitApp.exitApp();
}
}
};
...
}
Copy as android/app/src/main/assets/app_watchdogd.sh when building, save as /data/data/com.domain.appname/files/app_watchdogd.sh when running, then su -c /data/data/com.domain.appname/files/app_watchdogd.sh & from Java.