centos一键wordpress,seo优化百度技术排名教程,长沙企业网站排名优化,iis 网站目录权限设置在Android 12.0系统中#xff0c;实现进程保活白名单功能是为了确保某些重要的应用程序即使进入后台也能长时间保持运行状态#xff0c;不被系统自动杀死。这一功能的实现涉及多个核心类和文件#xff0c;以下是具体的实现步骤和核心功能分析#xff1a;
一、实现步骤 … 在Android 12.0系统中实现进程保活白名单功能是为了确保某些重要的应用程序即使进入后台也能长时间保持运行状态不被系统自动杀死。这一功能的实现涉及多个核心类和文件以下是具体的实现步骤和核心功能分析
一、实现步骤
1.1 在IActivityManager.aidl中增加接口 需要在IActivityManager.aidl文件中增加与进程白名单相关的接口例如void addWhiteListApp(String packageName)用于添加应用到白名单void removeWhiteListApp(String packageName)用于从白名单中移除应用。
1.2 在ActivityManager.java中提供接口给应用调用 在ActivityManager.java文件中需要实现上述接口使得应用可以通过ActivityManager对象调用这些接口来操作进程白名单。
1.3 在ActivityManagerService.java中实现接口逻辑 在ActivityManagerService.java文件中需要实现接口的具体逻辑包括将应用添加到白名单或从白名单中移除以及确保在系统杀进程时不杀死白名单中的进程。
1.4 在ActivityStackSupervisor和OomAdjuster.java中处理白名单进程 在ActivityStackSupervisor.java和OomAdjuster.java文件中需要添加对白名单进程的处理逻辑。例如在OomAdjuster.java中可以修改进程的OOMOut Of Memory调整策略以确保白名单中的进程在内存不足时不会被优先杀死。 二、涉及文件类路径 frameworks/base/core/java/android/app/IActivityManager.aidlframeworks/base/core/java/android/app/ActivityManager.javaframeworks/base/services/core/java/com/android/server/am/ActivityManagerService.javaframeworks/base/services/core/java/com/android/server/wm/ActivityTaskSupervisor.javaframeworks/base/services/core/java/com/android/server/am/OomAdjuster.java 三、具体实现 3.1 app进程保活白名单功能实现的核心功能实现和分析 3.1.1在lActivityManager.aidl中新增进程白名单的接口 void killUidForPermissionChange(int appId, int userId, String reason);boolean enableAppFreezer(in boolean enable); ListString getWhiteAppProcessList(); void setWhiteAppProcessList(in ListString whiteAppProcessList); 3.1.2在ActivityManager.java中增加白名单接口给app调用 public ListString getWhiteAppProcessList() {try {return getService().getWhiteAppProcessList();} catch (RemoteException e) {throw e.rethrowFromSystemServer();}}public void setWhiteAppProcessList(ListString whiteAppProcessList) {try {getService().setWhiteAppList(whiteAppProcessList);} catch (RemoteException e) {throw e.rethrowFromSystemServer();}}
在ActivityManagerjava中增加这两个关于app进程白名单的接口通过调用ActivityManagerService.java的白名单接口来设置app进程白名单实现保活app进程。
3.2 ActivityManagerService.java中实现lActivityManager.aidl的白名单接口 1.实现保活白名单接口public class ActivityManagerService extends IActivityManager.Stubimplements Watchdog.Monitor, BatteryStatsImpl.BatteryCallback {private ListString mWhiteAppProcessList new ArrayListString();public void setWindowManager(WindowManagerService wm) {synchronized (this) {mWindowManager wm;mWmInternal LocalServices.getService(WindowManagerInternal.class);mActivityTaskManager.setWindowManager(wm);}}public void setUsageStatsManager(UsageStatsManagerInternal usageStatsManager) {mUsageStatsService usageStatsManager;mActivityTaskManager.setUsageStatsManager(usageStatsManager);}//add core startprivate ListString mWhiteAppProcessList;Overridepublic ListString getWhiteAppProcessList() {return mWhiteAppProcessList;}Overridepublic void setWhiteAppProcessList(ListString whiteAppProcessList) {this.mWhiteAppProcessList whiteAppProcessList;}//add core end
从AcivityManagerService中可以看出继承了IActivityManager.Stub所以说就是IActivityManager的子类所以需要实现IAcivityManager定义的保活白名单接口接下来看下关于杀进程的相关方法. /*** Main function for removing an existing process from the activity manager* as a result of that process going away. Clears out all connections* to the process.*/GuardedBy(this)final void handleAppDiedLocked(ProcessRecord app,boolean restarting, boolean allowRestart) {int pid app.pid;boolean kept cleanUpApplicationRecordLocked(app, restarting, allowRestart, -1,false /*replacingPid*/);if (!kept !restarting) {removeLruProcessLocked(app);if (pid 0) {ProcessList.remove(pid);}}if (mProfileData.getProfileProc() app) {clearProfilerLocked();}mAtmInternal.handleAppDied(app.getWindowProcessController(), restarting, () - {Slog.w(TAG, Crash of app app.processName running instrumentation app.getActiveInstrumentation().mClass);Bundle info new Bundle();info.putString(shortMsg, Process crashed.);finishInstrumentationLocked(app, Activity.RESULT_CANCELED, info);});}
从handleAppDiedLocked的注释中可以看出在ActivityManagerService.java中主要是调用handleAppDiedLocked处理杀掉进程的功能的而在cleanUpApplicationRecordLocked中主要处理杀进程的工作接下来看cleanUpApplicationRecordLocked相关进程处理的方法。 GuardedBy(this)final boolean cleanUpApplicationRecordLocked(ProcessRecord app,boolean restarting, boolean allowRestart, int index, boolean replacingPid) {if (index 0) {removeLruProcessLocked(app);ProcessList.remove(app.pid);}mProcessesToGc.remove(app);mPendingPssProcesses.remove(app);ProcessList.abortNextPssTime(app.procStateMemTracker);// Dismiss any open dialogs.app.getDialogController().clearAllErrorDialogs();app.setCrashing(false);app.setNotResponding(false);app.resetPackageList(mProcessStats);app.unlinkDeathRecipient();app.makeInactive(mProcessStats);app.waitingToKill null;app.forcingToImportant null;updateProcessForegroundLocked(app, false, 0, false);app.setHasForegroundActivities(false);app.hasShownUi false;app.treatLikeActivity false;app.hasAboveClient false;app.setHasClientActivities(false);mServices.killServicesLocked(app, allowRestart);boolean restart false;// Remove published content providers.for (int i app.pubProviders.size() - 1; i 0; i--) {ContentProviderRecord cpr app.pubProviders.valueAt(i);if (cpr.proc ! app) {// If the hosting process record isnt really us, bail outcontinue;}final boolean alwaysRemove app.bad || !allowRestart;final boolean inLaunching removeDyingProviderLocked(app, cpr, alwaysRemove);if (!alwaysRemove inLaunching cpr.hasConnectionOrHandle()) {// We left the provider in the launching list, need to// restart it.restart true;}cpr.provider null;cpr.setProcess(null);}app.pubProviders.clear();// Take care of any launching providers waiting for this process.if (cleanupAppInLaunchingProvidersLocked(app, false)) {mProcessList.noteProcessDiedLocked(app);restart true;}// Unregister from connected content providers.if (!app.conProviders.isEmpty()) {for (int i app.conProviders.size() - 1; i 0; i--) {ContentProviderConnection conn app.conProviders.get(i);conn.provider.connections.remove(conn);stopAssociationLocked(app.uid, app.processName, conn.provider.uid,conn.provider.appInfo.longVersionCode, conn.provider.name,conn.provider.info.processName);}app.conProviders.clear();}// At this point there may be remaining entries in mLaunchingProviders// where we were the only one waiting, so they are no longer of use.// Look for these and clean up if found.// XXX Commented out for now. Trying to figure out a way to reproduce// the actual situation to identify what is actually going on.if (false) {for (int i mLaunchingProviders.size() - 1; i 0; i--) {ContentProviderRecord cpr mLaunchingProviders.get(i);if (cpr.connections.size() 0 !cpr.hasExternalProcessHandles()) {synchronized (cpr) {cpr.launchingApp null;cpr.notifyAll();}}}}skipCurrentReceiverLocked(app);// Unregister any receivers.for (int i app.receivers.size() - 1; i 0; i--) {removeReceiverLocked(app.receivers.valueAt(i));}app.receivers.clear();// If the app is undergoing backup, tell the backup manager about itfinal BackupRecord backupTarget mBackupTargets.get(app.userId);if (backupTarget ! null app.pid backupTarget.app.pid) {if (DEBUG_BACKUP || DEBUG_CLEANUP) Slog.d(TAG_CLEANUP, App backupTarget.appInfo died during backup);mHandler.post(new Runnable() {Overridepublic void run(){try {IBackupManager bm IBackupManager.Stub.asInterface(ServiceManager.getService(Context.BACKUP_SERVICE));bm.agentDisconnectedForUser(app.userId, app.info.packageName);} catch (RemoteException e) {// cant happen; backup manager is local}}});}for (int i mPendingProcessChanges.size() - 1; i 0; i--) {ProcessChangeItem item mPendingProcessChanges.get(i);if (app.pid 0 item.pid app.pid) {mPendingProcessChanges.remove(i);mAvailProcessChanges.add(item);}}mUiHandler.obtainMessage(DISPATCH_PROCESS_DIED_UI_MSG, app.pid, app.info.uid,null).sendToTarget();// If this is a precede instance of another process instanceallowRestart true;synchronized (app) {if (app.mSuccessor ! null) {// We dont allow restart with this ProcessRecord now,// because we have created a new one already.allowRestart false;// If its persistent, add the successor to mPersistentStartingProcessesif (app.isPersistent() !app.removed) {if (mPersistentStartingProcesses.indexOf(app.mSuccessor) 0) {mPersistentStartingProcesses.add(app.mSuccessor);}}// clean up the field so the successors proc starter could proceed.app.mSuccessor.mPrecedence null;app.mSuccessor null;// Notify if anyone is waiting for it.app.notifyAll();}}// If the caller is restarting this app, then leave it in its// current lists and let the caller take care of it.if (restarting) {return false;}if (!app.isPersistent() || app.isolated) {if (DEBUG_PROCESSES || DEBUG_CLEANUP) Slog.v(TAG_CLEANUP,Removing non-persistent process during cleanup: app);if (!replacingPid) {mProcessList.removeProcessNameLocked(app.processName, app.uid, app);}mAtmInternal.clearHeavyWeightProcessIfEquals(app.getWindowProcessController());} else if (!app.removed) {// This app is persistent, so we need to keep its record around.// If it is not already on the pending app list, add it there// and start a new process for it.if (mPersistentStartingProcesses.indexOf(app) 0) {mPersistentStartingProcesses.add(app);restart true;}}.....return false;}
在cleanUpApplicationRecordLocked中的进行进程列表遍历的时候判断app是否清除的时候根据if (!app.isPersistent() app.isolated) 调用 mAtmlntemnal.clearHeavyWeightProcesslfEquals(app.getWindowProcesscontroler();来杀掉进程所以可以在这里增加判断添加 看是否杀掉进程 具体修改如下: --- a/frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java b/frameworks/base/services/core/java/com/android/server/am/ActivityManagerService.java -14079,8 14079,13 public class ActivityManagerService extends IActivityManager.Stubif (restarting) {return false;}-- if (!app.isPersistent() || app.isolated) { ListString lists this.mWhiteAppProcessList; boolean iskeepAlivefalse; if(lists!null lists.contains(app.processName)){ iskeepAlivetrue; } if ((!app.isPersistent() || app.isolated) !iskeepAlive) {if (DEBUG_PROCESSES || DEBUG_CLEANUP) Slog.v(TAG_CLEANUP,Removing non-persistent process during cleanup: app);if (!replacingPid) { -14097,6 14102,7 public class ActivityManagerService extends IActivityManager.Stub// This app is persistent, so we need to keep its record around.// If it is not already on the pending app list, add it there// and start a new process for it.if (mPersistentStartingProcesses.indexOf(app) 0) {mPersistentStartingProcesses.add(app);restart true;
3.3 ActivityStackSupervisor.java中关于任务栈中杀进程的相关功能分析 Overridepublic void onRecentTaskRemoved(Task task, boolean wasTrimmed, boolean killProcess) {if (wasTrimmed) {// Task was trimmed from the recent tasks list -- remove the active task record as well// since the user wont really be able to go back to itremoveTaskById(task.mTaskId, killProcess, false /* removeFromRecents */,recent-task-trimmed);}task.removedFromRecents();}boolean removeTaskById(int taskId, boolean killProcess, boolean removeFromRecents,String reason) {final Task task mRootWindowContainer.anyTaskForId(taskId, MATCH_TASK_IN_STACKS_OR_RECENT_TASKS);if (task ! null) {removeTask(task, killProcess, removeFromRecents, reason);return true;}Slog.w(TAG, Request to remove task ignored for non-existent task taskId);return false;}void removeTask(Task task, boolean killProcess, boolean removeFromRecents, String reason) {if (task.mInRemoveTask) {// Prevent recursion.return;}task.mInRemoveTask true;try {task.performClearTask(reason);cleanUpRemovedTaskLocked(task, killProcess, removeFromRecents);mService.getLockTaskController().clearLockedTask(task);mService.getTaskChangeNotificationController().notifyTaskStackChanged();if (task.isPersistable) {mService.notifyTaskPersisterLocked(null, true);}} finally {task.mInRemoveTask false;}}
在AcivitvStackSupervisor.java中关于移除栈内的app进程主要是在onRecentTaskRemoved中通过调用removeTaskByld实现的而removeTaskByld又是调用removeTask实现的具体是在removeTask中处理的杀进程所以具体实现如下: boolean removeTaskById(int taskId, boolean killProcess, boolean removeFromRecents,String reason) {final Task task mRootWindowContainer.anyTaskForId(taskId, MATCH_TASK_IN_STACKS_OR_RECENT_TASKS);if (task ! null) {//add code startComponentName component tr.getBaseIntent().getComponent();if(component!null){String pkgcomponent.getPackageName();ActivityManager am (ActivityManager) mService.mContext.getSystemService(Context.ACTIVITY_SERVICE);ListString listam.getWhiteAppProcessList();if(list!null list.contains(pkg)){return false;}}//add code endremoveTask(task, killProcess, removeFromRecents, reason);return true;}Slog.w(TAG, Request to remove task ignored for non-existent task taskId);return false;}
3.4OomAdjuster.java中关于对保活白名单的分析 private boolean isInWhitelist(ProcessRecord pr) { String pkgName pr.info.packageName; ListString mLmKillerBypassPackages mService.getKeepAliveList(); if(mLmKillerBypassPackages!null mLmKillerBypassPackages.size()0){ for (String token : mLmKillerBypassPackages) { if (pkgName.startsWith(token)) { return true; } } } return false; }/** Applies the computed oomadj, procstate and sched group values and freezes them in set* */GuardedBy(mService)private final boolean applyOomAdjLocked(ProcessRecord app, boolean doingAll, long now,long nowElapsed) {boolean success true;if (app.getCurRawAdj() ! app.setRawAdj) {app.setRawAdj app.getCurRawAdj();}int changes 0;// dont compact during bootupif (mCachedAppOptimizer.useCompaction() mService.mBooted) {// Cached and prev/home compactionif (app.curAdj ! app.setAdj) {// Perform a minor compaction when a perceptible app becomes the prev/home app// Perform a major compaction when any app enters cached// reminder: here, setAdj is previous state, curAdj is upcoming stateif (app.setAdj ProcessList.PERCEPTIBLE_APP_ADJ (app.curAdj ProcessList.PREVIOUS_APP_ADJ ||app.curAdj ProcessList.HOME_APP_ADJ)) {mCachedAppOptimizer.compactAppSome(app);} else if ((app.setAdj ProcessList.CACHED_APP_MIN_ADJ|| app.setAdj ProcessList.CACHED_APP_MAX_ADJ) app.curAdj ProcessList.CACHED_APP_MIN_ADJ app.curAdj ProcessList.CACHED_APP_MAX_ADJ) {mCachedAppOptimizer.compactAppFull(app);}} else if (mService.mWakefulness ! PowerManagerInternal.WAKEFULNESS_AWAKE app.setAdj ProcessList.FOREGROUND_APP_ADJ// Because these can fire independent of oom_adj/procstate changes, we need// to throttle the actual dispatch of these requests in addition to the// processing of the requests. As a result, there is throttling both here// and in CachedAppOptimizer. mCachedAppOptimizer.shouldCompactPersistent(app, now)) {mCachedAppOptimizer.compactAppPersistent(app);} else if (mService.mWakefulness ! PowerManagerInternal.WAKEFULNESS_AWAKE app.getCurProcState() ActivityManager.PROCESS_STATE_BOUND_FOREGROUND_SERVICE mCachedAppOptimizer.shouldCompactBFGS(app, now)) {mCachedAppOptimizer.compactAppBfgs(app);}}if (app.curAdj ! app.setAdj) {// 主要修改部分开始// 注释代码开始/*ProcessList.setOomAdj(app.pid, app.uid, app.curAdj);if (DEBUG_SWITCH || DEBUG_OOM_ADJ || mService.mCurOomAdjUid app.info.uid) {String msg Set app.pid app.processName adj app.curAdj : app.adjType;reportOomAdjMessageLocked(TAG_OOM_ADJ, msg);}app.setAdj app.curAdj;app.verifiedAdj ProcessList.INVALID_ADJ;*/// 注释代码结束 boolean isAppWhiteProcess false; if(isInWhitelist(app) (app.curAdj ProcessList.PERSISTENT_SERVICE_ADJ))isAppWhiteProcess true; if(isAppWhiteProcess){ Slog.d(TAG,isAppWhiteProcess); ProcessList.setOomAdj(app.pid, app.uid, ProcessList.PERSISTENT_SERVICE_ADJ); if (DEBUG_SWITCH || DEBUG_OOM_ADJ || mService.mCurOomAdjUid app.info.uid) { String msg Set app.pid app.processName adj app.curAdj : app.adjType; reportOomAdjMessageLocked(TAG_OOM_ADJ, msg); } app.setAdj ProcessList.PERSISTENT_SERVICE_ADJ; app.verifiedAdj ProcessList.INVALID_ADJ; }else{ ProcessList.setOomAdj(app.pid, app.uid, app.curAdj); if (DEBUG_SWITCH || DEBUG_OOM_ADJ || mService.mCurOomAdjUid app.info.uid) { String msg Set app.pid app.processName adj app.curAdj : app.adjType; reportOomAdjMessageLocked(TAG_OOM_ADJ, msg); } app.setAdj app.curAdj; app.verifiedAdj ProcessList.INVALID_ADJ; }}.....return success;}
在上述的OomAdjuster.java的代码中首选通过isInWhitelist(ProcessRecord pr)判断当前进程是否在白名单之内然后通过设置app.setAdj和app.verifiedAdj 两个值来确保app不会被杀掉.
