support keep alive on android 4.4~8.0

.gitignore

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+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.cxx

README.md

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+# KeepAlive
+KeepAlive是在[Leoric](https://github.com/tiann/Leoric)(通过JNI复活进程)的基础上，实现了通过ioctl复活进程，能最大程度提高复活率。
+
+`master`分支是`利用 libbinder.so 与 ActivityManagerService 通信`的版本，`ioctl`分支是`使用 ioctl 与 binder 驱动通信`的版本。
+
+## 使用方法
+1. 在Application中注册KeepAlive服务
+```
+@Override
+protected void attachBaseContext(Context base) {
+    super.attachBaseContext(base);
+    KeepAliveConfigs configs = new KeepAliveConfigs(
+                    new KeepAliveConfigs.Config(getPackageName() + ":resident",
+                            Service1.class.getCanonicalName()));
+    KeepAlive.init(base, configs);
+}
+```
+
+2. Service1对应的进程名是":resident"，或者其它任意命名
+```
+<service
+    android:name="Service1"
+    android:process=":resident" />
+```
+Service需要继承KeepAliveService，否则在Android4.4上将没有保活效果。
+
+3. 在合适的地方，启动Service1，它将自动唤醒保活进程
+```
+startService(new Intent(MainActivity.this, Service1.class));
+```
+如果需要服务自启动，看第6条。
+
+4. 忽略电池优化
+```
+configs.ignoreBatteryOptimization();
+```
+
+5. 防止短时间内重复启动
+```
+// 配置短时间重启限制，每次重启间隔限制是10s，最多允许3次10秒内的连续重启
+configs.rebootThreshold(10*1000, 3);
+```
+注：保活和重启限制相违背，更准确的应该做崩溃重启限制。
+
+6. 设置应用自启执行的操作
+```
+configs.setOnBootReceivedListener(new KeepAliveConfigs.OnBootReceivedListener() {
+    @Override
+    public void onReceive(Context context, Intent intent) {
+        // 设置服务自启
+        context.startService(new Intent(context, Service1.class));
+    }
+});
+```
+
+## 实现原理
+
+- [Android 黑科技保活实现原理揭秘](http://weishu.me/2020/01/16/a-keep-alive-method-on-android/)
+- [深度剖析App保活案例](http://www.52im.net/forum.php?mod=viewthread&tid=2893&highlight=%B1%A3%BB%EE)
+
+## 应对方法
+
+下面是一种简单的方法杀死 KeepAlive:
+
+```
+ps -A | grep `ps -A | grep keepalive | awk '{print $1}' | head -1` | awk '{print $2}' | xargs kill -19 && am force-stop com.boolbird.keepalive
+```
+
+对于系统有两种思路可以选择：
+
+1. 加入在 force-stop 期间不允许启动新的进程的逻辑
+2. 修改 force-stop 的杀进程逻辑为：预先收集好所有进程再进行 kill（如有必要还可以先发送 SIGSTOP）
+
+## 测试
+项目根目录下的kill_alive.sh用于重复杀进程测试。
+
+## 问题
+1、怎么保活多个进程
+2、避免在Application中初始化第三方库，避免在所有进程都初始化第三方库

app/.gitignore

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+/build

app/build.gradle

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+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 29
+    buildToolsVersion "29.0.2"
+    defaultConfig {
+        applicationId 'com.boolbird.keepalive'
+        minSdkVersion 19
+        targetSdkVersion 22
+        versionCode 1
+        versionName "1.0"
+        ndk {
+            abiFilters "armeabi-v7a", "arm64-v8a", "x86", "x86_64"
+        }
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+    lintOptions {
+        abortOnError false
+    }
+
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation project(":library")
+}

app/proguard-rules.pro

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+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

app/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    package="com.boolbird.keepalive.demo">
+
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS" />
+
+    <application
+        android:name="com.boolbird.keepalive.demo.MainApplication"
+        android:label="KeepAlive"
+        android:supportsRtl="true"
+        android:icon="@mipmap/ic_launcher"
+        tools:ignore="GoogleAppIndexingWarning">
+        <activity
+            android:name="com.boolbird.keepalive.demo.MainActivity"
+            android:label="KeepAlive"
+            android:theme="@android:style/Theme.NoTitleBar">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+        <service
+            android:name="com.boolbird.keepalive.demo.Service1"
+            android:process=":resident" />
+    </application>
+
+</manifest>

app/src/main/java/com/boolbird/keepalive/demo/MainActivity.java

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+package com.boolbird.keepalive.demo;
+
+import android.app.Activity;
+import android.os.Bundle;
+
+public class MainActivity extends Activity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main);
+
+//        startService(new Intent(MainActivity.this, Service1.class));
+    }
+}