Proper way to ensure process dies before restart it (0310907d) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/am/ActivityManagerService.java

+10 −8

Original line number	Diff line number	Diff line
		@@ -6694,7 +6694,7 @@ public class ActivityManagerService extends IActivityManager.Stub

		private final long[] mProcessStateStatsLongs = new long[1];

		private boolean isProcessAliveLocked(ProcessRecord proc) {
		boolean isProcessAliveLocked(ProcessRecord proc) {
		if (proc.pid <= 0) {
		if (DEBUG_OOM_ADJ) Slog.d(TAG, "Process hasn't started yet: " + proc);
		return false;
		@@ -6711,7 +6711,10 @@ public class ActivityManagerService extends IActivityManager.Stub
		final long state = mProcessStateStatsLongs[0];
		if (DEBUG_OOM_ADJ) Slog.d(TAG, "RETRIEVED STATE FOR " + proc.procStatFile + ": "
		+ (char)state);
		return state != 'Z' && state != 'X' && state != 'x' && state != 'K';
		if (state != 'Z' && state != 'X' && state != 'x' && state != 'K') {
		return Process.getUidForPid(proc.pid) == proc.uid;
		}
		return false;
		}

		private String checkContentProviderAssociation(ProcessRecord callingApp, int callingUid,
		@@ -6784,14 +6787,14 @@ public class ActivityManagerService extends IActivityManager.Stub
		// (See the commit message on I2c4ba1e87c2d47f2013befff10c49b3dc337a9a7 to see
		// how to test this case.)
		if (cpr.proc.killed && cpr.proc.killedByAm) {
		checkTime(startTime, "getContentProviderImpl: before appDied (killedByAm)");
		final long iden = Binder.clearCallingIdentity();
		try {
		appDiedLocked(cpr.proc);
		mProcessList.killProcAndWaitIfNecessaryLocked(cpr.proc, false,
		cpr.uid == cpr.proc.uid \|\| cpr.proc.isolated,
		"getContentProviderImpl: %s (killedByAm)", startTime);
		} finally {
		Binder.restoreCallingIdentity(iden);
		}
		checkTime(startTime, "getContentProviderImpl: after appDied (killedByAm)");
		}
		}

		@@ -6895,9 +6898,8 @@ public class ActivityManagerService extends IActivityManager.Stub
		Slog.i(TAG, "Existing provider " + cpr.name.flattenToShortString()
		+ " is crashing; detaching " + r);
		boolean lastRef = decProviderCountLocked(conn, cpr, token, stable);
		checkTime(startTime, "getContentProviderImpl: before appDied");
		appDiedLocked(cpr.proc);
		checkTime(startTime, "getContentProviderImpl: after appDied");
		mProcessList.killProcAndWaitIfNecessaryLocked(cpr.proc,
		false, true, "getContentProviderImpl: %s", startTime);
		if (!lastRef) {
		// This wasn't the last ref our process had on
		// the provider... we have now been killed, bail.

services/core/java/com/android/server/am/ProcessList.java

+82 −6

Original line number	Diff line number	Diff line
		@@ -78,6 +78,9 @@ import android.os.Trace;
		import android.os.UserHandle;
		import android.os.storage.StorageManager;
		import android.os.storage.StorageManagerInternal;
		import android.system.ErrnoException;
		import android.system.Os;
		import android.system.OsConstants;
		import android.text.TextUtils;
		import android.util.ArrayMap;
		import android.util.EventLog;
		@@ -283,6 +286,16 @@ public final class ProcessList {
		// lmkd reconnect delay in msecs
		private final static long LMDK_RECONNECT_DELAY_MS = 1000;

		/**
		* How long between a process kill and we actually receive its death recipient
		*/
		private static final long PROC_KILL_TIMEOUT = 2000; // 2 seconds;

		/**
		* How long between polls to check if the given process is dead or not.
		*/
		private static final long PROC_DEATH_POLL_INTERVAL = 100;

		ActivityManagerService mService = null;

		// To kill process groups asynchronously
		@@ -1421,7 +1434,7 @@ public final class ProcessList {
		if (app.pendingStart) {
		return true;
		}
		long startTime = SystemClock.elapsedRealtime();
		long startTime = SystemClock.uptimeMillis();
		if (app.pid > 0 && app.pid != ActivityManagerService.MY_PID) {
		checkSlow(startTime, "startProcess: removing from pids map");
		mService.mPidsSelfLocked.remove(app);
		@@ -1856,7 +1869,7 @@ public final class ProcessList {
		boolean knownToBeDead, int intentFlags, HostingRecord hostingRecord,
		boolean allowWhileBooting, boolean isolated, int isolatedUid, boolean keepIfLarge,
		String abiOverride, String entryPoint, String[] entryPointArgs, Runnable crashHandler) {
		long startTime = SystemClock.elapsedRealtime();
		long startTime = SystemClock.uptimeMillis();
		ProcessRecord app;
		if (!isolated) {
		app = getProcessRecordLocked(processName, info.uid, keepIfLarge);
		@@ -1917,10 +1930,9 @@ public final class ProcessList {
		// An application record is attached to a previous process,
		// clean it up now.
		if (DEBUG_PROCESSES) Slog.v(TAG_PROCESSES, "App died: " + app);
		checkSlow(startTime, "startProcess: bad proc running, killing");
		ProcessList.killProcessGroup(app.uid, app.pid);
		mService.handleAppDiedLocked(app, true, true);
		checkSlow(startTime, "startProcess: done killing old proc");
		// do the killing
		killProcAndWaitIfNecessaryLocked(app, true, app.uid == info.uid \|\| app.isolated,
		"startProcess: bad proc running, killing: %s", startTime);
		}

		if (app == null) {
		@@ -1961,6 +1973,70 @@ public final class ProcessList {
		return success ? app : null;
		}

		/**
		* A lite version of checking if a process is alive or not, by using kill(2) with signal 0.
		*
		* <p>
		* Note that, zombie processes are stil "alive" in this case, use the {@link
		* ActivityManagerService#isProcessAliveLocked} if zombie processes need to be excluded.
		* </p>
		*/
		@GuardedBy("mService")
		private boolean isProcessAliveLiteLocked(ProcessRecord app) {
		try {
		Os.kill(app.pid, 0);
		} catch (ErrnoException e) {
		return e.errno != OsConstants.ESRCH;
		}
		return true;
		}

		/**
		* Kill (if asked to) and wait for the given process died if necessary
		* @param app - The process record to kill
		* @param doKill - Kill the given process record
		* @param wait - Wait for the death of the given process
		* @param formatString - The log message for slow operation
		* @param startTime - The start timestamp of the operation
		*/
		@GuardedBy("mService")
		void killProcAndWaitIfNecessaryLocked(final ProcessRecord app, final boolean doKill,
		final boolean wait, final String formatString, final long startTime) {

		checkSlow(startTime, String.format(formatString, "before appDied"));

		if (doKill) {
		// do the killing
		ProcessList.killProcessGroup(app.uid, app.pid);
		}

		// wait for the death
		if (wait) {
		boolean isAlive = true;
		// ideally we should use pidfd_open(2) but it's available on kernel 5.3 or later

		final long timeout = SystemClock.uptimeMillis() + PROC_KILL_TIMEOUT;
		isAlive = isProcessAliveLiteLocked(app);
		while (timeout > SystemClock.uptimeMillis() && isAlive) {
		try {
		Thread.sleep(PROC_DEATH_POLL_INTERVAL);
		} catch (InterruptedException e) {
		}
		isAlive = isProcessAliveLiteLocked(app);
		}

		if (isAlive) {
		// Maybe the process goes into zombie, use an expensive API to check again.
		if (mService.isProcessAliveLocked(app)) {
		Slog.w(TAG, String.format(formatString,
		"waiting for app killing timed out"));
		}
		}
		}

		checkSlow(startTime, String.format(formatString, "after appDied"));
		}

		@GuardedBy("mService")
		private String isProcStartValidLocked(ProcessRecord app, long expectedStartSeq) {
		StringBuilder sb = null;