Implement ActivityManager to LMKD reconnect functionality (3f6b33b8) · Commits · e / os / android_frameworks_base

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

0 → 100644

+291 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2019 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.android.server.am;

		import static android.os.MessageQueue.OnFileDescriptorEventListener.EVENT_ERROR;
		import static android.os.MessageQueue.OnFileDescriptorEventListener.EVENT_INPUT;

		import static com.android.server.am.ActivityManagerDebugConfig.TAG_AM;
		import static com.android.server.am.ActivityManagerDebugConfig.TAG_WITH_CLASS_NAME;

		import android.net.LocalSocket;
		import android.net.LocalSocketAddress;
		import android.os.MessageQueue;
		import android.util.Slog;

		import com.android.internal.annotations.GuardedBy;

		import libcore.io.IoUtils;

		import java.io.FileDescriptor;
		import java.io.IOException;
		import java.io.InputStream;
		import java.io.OutputStream;
		import java.nio.ByteBuffer;

		/**
		* Lmkd connection to communicate with lowmemorykiller daemon.
		*/
		public class LmkdConnection {
		private static final String TAG = TAG_WITH_CLASS_NAME ? "LmkdConnection" : TAG_AM;

		// lmkd reply max size in bytes
		private static final int LMKD_REPLY_MAX_SIZE = 8;

		// connection listener interface
		interface LmkdConnectionListener {
		boolean onConnect(OutputStream ostream);
		void onDisconnect();
		/**
		* Check if received reply was expected (reply to an earlier request)
		*
		* @param replyBuf The buffer provided in exchange() to receive the reply.
		* It can be used by exchange() caller to store reply-specific
		* tags for later use in isReplyExpected() to verify if
		* received packet is the expected reply.
		* @param dataReceived The buffer holding received data
		* @param receivedLen Size of the data received
		*/
		boolean isReplyExpected(ByteBuffer replyBuf, ByteBuffer dataReceived,
		int receivedLen);
		}

		private final MessageQueue mMsgQueue;

		// lmkd connection listener
		private final LmkdConnectionListener mListener;

		// mutex to synchronize access to the socket
		private final Object mLmkdSocketLock = new Object();

		// socket to communicate with lmkd
		@GuardedBy("mLmkdSocketLock")
		private LocalSocket mLmkdSocket = null;

		// socket I/O streams
		@GuardedBy("mLmkdSocketLock")
		private OutputStream mLmkdOutputStream = null;
		@GuardedBy("mLmkdSocketLock")
		private InputStream mLmkdInputStream = null;

		// buffer to store incoming data
		private final ByteBuffer mInputBuf =
		ByteBuffer.allocate(LMKD_REPLY_MAX_SIZE);

		// object to protect mReplyBuf and to wait/notify when reply is received
		private final Object mReplyBufLock = new Object();

		// reply buffer
		@GuardedBy("mReplyBufLock")
		private ByteBuffer mReplyBuf = null;

		//////////////////// END FIELDS ////////////////////

		LmkdConnection(MessageQueue msgQueue, LmkdConnectionListener listener) {
		mMsgQueue = msgQueue;
		mListener = listener;
		}

		boolean connect() {
		synchronized (mLmkdSocketLock) {
		if (mLmkdSocket != null) {
		return true;
		}
		// temporary sockets and I/O streams
		final LocalSocket socket = openSocket();

		if (socket == null) {
		Slog.w(TAG, "Failed to connect to lowmemorykiller, retry later");
		return false;
		}

		final OutputStream ostream;
		final InputStream istream;
		try {
		ostream = socket.getOutputStream();
		istream = socket.getInputStream();
		} catch (IOException ex) {
		IoUtils.closeQuietly(socket);
		return false;
		}
		// execute onConnect callback
		if (mListener != null && !mListener.onConnect(ostream)) {
		Slog.w(TAG, "Failed to communicate with lowmemorykiller, retry later");
		IoUtils.closeQuietly(socket);
		return false;
		}
		// connection established
		mLmkdSocket = socket;
		mLmkdOutputStream = ostream;
		mLmkdInputStream = istream;
		mMsgQueue.addOnFileDescriptorEventListener(mLmkdSocket.getFileDescriptor(),
		EVENT_INPUT \| EVENT_ERROR,
		new MessageQueue.OnFileDescriptorEventListener() {
		public int onFileDescriptorEvents(FileDescriptor fd, int events) {
		return fileDescriptorEventHandler(fd, events);
		}
		}
		);
		mLmkdSocketLock.notifyAll();
		}
		return true;
		}

		private int fileDescriptorEventHandler(FileDescriptor fd, int events) {
		if (mListener == null) {
		return 0;
		}
		if ((events & EVENT_INPUT) != 0) {
		processIncomingData();
		}
		if ((events & EVENT_ERROR) != 0) {
		synchronized (mLmkdSocketLock) {
		// stop listening on this socket
		mMsgQueue.removeOnFileDescriptorEventListener(
		mLmkdSocket.getFileDescriptor());
		IoUtils.closeQuietly(mLmkdSocket);
		mLmkdSocket = null;
		}
		// wake up reply waiters if any
		synchronized (mReplyBufLock) {
		if (mReplyBuf != null) {
		mReplyBuf = null;
		mReplyBufLock.notifyAll();
		}
		}
		// notify listener
		mListener.onDisconnect();
		return 0;
		}
		return (EVENT_INPUT \| EVENT_ERROR);
		}

		private void processIncomingData() {
		int len = read(mInputBuf);
		if (len > 0) {
		synchronized (mReplyBufLock) {
		if (mReplyBuf != null) {
		if (mListener.isReplyExpected(mReplyBuf, mInputBuf, len)) {
		// copy into reply buffer
		mReplyBuf.put(mInputBuf.array(), 0, len);
		mReplyBuf.rewind();
		// wakeup the waiting thread
		mReplyBufLock.notifyAll();
		} else {
		// received asynchronous or unexpected packet
		// treat this as an error
		mReplyBuf = null;
		mReplyBufLock.notifyAll();
		Slog.e(TAG, "Received unexpected packet from lmkd");
		}
		} else {
		// received asynchronous communication from lmkd
		// we don't support this yet
		Slog.w(TAG, "Received an asynchronous packet from lmkd");
		}
		}
		}
		}

		boolean isConnected() {
		synchronized (mLmkdSocketLock) {
		return (mLmkdSocket != null);
		}
		}

		boolean waitForConnection(long timeoutMs) {
		synchronized (mLmkdSocketLock) {
		if (mLmkdSocket != null) {
		return true;
		}
		try {
		mLmkdSocketLock.wait(timeoutMs);
		return (mLmkdSocket != null);
		} catch (InterruptedException e) {
		return false;
		}
		}
		}

		private LocalSocket openSocket() {
		final LocalSocket socket;

		try {
		socket = new LocalSocket(LocalSocket.SOCKET_SEQPACKET);
		socket.connect(
		new LocalSocketAddress("lmkd",
		LocalSocketAddress.Namespace.RESERVED));
		} catch (IOException ex) {
		Slog.e(TAG, "Connection failed: " + ex.toString());
		return null;
		}
		return socket;
		}

		private boolean write(ByteBuffer buf) {
		synchronized (mLmkdSocketLock) {
		try {
		mLmkdOutputStream.write(buf.array(), 0, buf.position());
		} catch (IOException ex) {
		return false;
		}
		return true;
		}
		}

		private int read(ByteBuffer buf) {
		synchronized (mLmkdSocketLock) {
		try {
		return mLmkdInputStream.read(buf.array(), 0, buf.array().length);
		} catch (IOException ex) {
		}
		return -1;
		}
		}

		/**
		* Exchange a request/reply packets with lmkd
		*
		* @param req The buffer holding the request data to be sent
		* @param repl The buffer to receive the reply
		*/
		public boolean exchange(ByteBuffer req, ByteBuffer repl) {
		if (repl == null) {
		return write(req);
		}

		boolean result = false;
		// set reply buffer to user-defined one to fill it
		synchronized (mReplyBufLock) {
		mReplyBuf = repl;

		if (write(req)) {
		try {
		// wait for the reply
		mReplyBufLock.wait();
		result = (mReplyBuf != null);
		} catch (InterruptedException ie) {
		result = false;
		}
		}

		// reset reply buffer
		mReplyBuf = null;
		}
		return result;
		}
		}

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

+68 −90

Original line number	Diff line number	Diff line
		@@ -57,8 +57,6 @@ import android.content.pm.ApplicationInfo;
		import android.content.pm.IPackageManager;
		import android.content.res.Resources;
		import android.graphics.Point;
		import android.net.LocalSocket;
		import android.net.LocalSocketAddress;
		import android.os.AppZygote;
		import android.os.Binder;
		import android.os.Build;
		@@ -103,11 +101,8 @@ import com.android.server.wm.WindowManagerService;

		import dalvik.system.VMRuntime;

		import libcore.io.IoUtils;

		import java.io.File;
		import java.io.IOException;
		import java.io.InputStream;
		import java.io.OutputStream;
		import java.io.PrintWriter;
		import java.nio.ByteBuffer;
		@@ -118,11 +113,6 @@ import java.util.List;

		/**
		* Activity manager code dealing with processes.
		*
		* Method naming convention:
		* <ul>
		* <li> Methods suffixed with "LS" should be called within the {@link #sLmkdSocketLock} lock.
		* </ul>
		*/
		public final class ProcessList {
		static final String TAG = TAG_WITH_CLASS_NAME ? "ProcessList" : TAG_AM;
		@@ -269,6 +259,9 @@ public final class ProcessList {
		static final byte LMK_PROCPURGE = 3;
		static final byte LMK_GETKILLCNT = 4;

		// lmkd reconnect delay in msecs
		private static final long LMDK_RECONNECT_DELAY_MS = 1000;

		ActivityManagerService mService = null;

		// To kill process groups asynchronously
		@@ -303,16 +296,9 @@ public final class ProcessList {

		private boolean mHaveDisplaySize;

		private static Object sLmkdSocketLock = new Object();
		private static LmkdConnection sLmkdConnection = null;

		@GuardedBy("sLmkdSocketLock")
		private static LocalSocket sLmkdSocket;

		@GuardedBy("sLmkdSocketLock")
		private static OutputStream sLmkdOutputStream;

		@GuardedBy("sLmkdSocketLock")
		private static InputStream sLmkdInputStream;
		private boolean mOomLevelsSet = false;

		/**
		* Temporary to avoid allocations. Protected by main lock.
		@@ -539,6 +525,7 @@ public final class ProcessList {

		final class KillHandler extends Handler {
		static final int KILL_PROCESS_GROUP_MSG = 4000;
		static final int LMDK_RECONNECT_MSG = 4001;

		public KillHandler(Looper looper) {
		super(looper, null, true);
		@@ -552,6 +539,15 @@ public final class ProcessList {
		Process.killProcessGroup(msg.arg1 /* uid /, msg.arg2 / pid */);
		Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
		break;
		case LMDK_RECONNECT_MSG:
		if (!sLmkdConnection.connect()) {
		Slog.i(TAG, "Failed to connect to lmkd, retry after "
		+ LMDK_RECONNECT_DELAY_MS + " ms");
		// retry after LMDK_RECONNECT_DELAY_MS
		sKillHandler.sendMessageDelayed(sKillHandler.obtainMessage(
		KillHandler.LMDK_RECONNECT_MSG), LMDK_RECONNECT_DELAY_MS);
		}
		break;

		default:
		super.handleMessage(msg);
		@@ -579,6 +575,30 @@ public final class ProcessList {
		THREAD_PRIORITY_BACKGROUND, true /* allowIo */);
		sKillThread.start();
		sKillHandler = new KillHandler(sKillThread.getLooper());
		sLmkdConnection = new LmkdConnection(sKillThread.getLooper().getQueue(),
		new LmkdConnection.LmkdConnectionListener() {
		@Override
		public boolean onConnect(OutputStream ostream) {
		Slog.i(TAG, "Connection with lmkd established");
		return onLmkdConnect(ostream);
		}
		@Override
		public void onDisconnect() {
		Slog.w(TAG, "Lost connection to lmkd");
		// start reconnection after delay to let lmkd restart
		sKillHandler.sendMessageDelayed(sKillHandler.obtainMessage(
		KillHandler.LMDK_RECONNECT_MSG), LMDK_RECONNECT_DELAY_MS);
		}
		@Override
		public boolean isReplyExpected(ByteBuffer replyBuf,
		ByteBuffer dataReceived, int receivedLen) {
		// compare the preambule (currently one integer) to check if
		// this is the reply packet we are waiting for
		return (receivedLen == replyBuf.array().length
		&& dataReceived.getInt(0) == replyBuf.getInt(0));
		}
		}
		);
		}
		}

		@@ -684,6 +704,7 @@ public final class ProcessList {

		writeLmkd(buf, null);
		SystemProperties.set("sys.sysctl.extra_free_kbytes", Integer.toString(reserve));
		mOomLevelsSet = true;
		}
		// GB: 2048,3072,4096,6144,7168,8192
		// HC: 8192,10240,12288,14336,16384,20480
		@@ -1223,93 +1244,50 @@ public final class ProcessList {
		buf.putInt(LMK_GETKILLCNT);
		buf.putInt(min_oom_adj);
		buf.putInt(max_oom_adj);
		if (writeLmkd(buf, repl)) {
		int i = repl.getInt();
		if (i != LMK_GETKILLCNT) {
		Slog.e("ActivityManager", "Failed to get kill count, code mismatch");
		return null;
		}
		// indicate what we are waiting for
		repl.putInt(LMK_GETKILLCNT);
		repl.rewind();
		if (writeLmkd(buf, repl) && repl.getInt() == LMK_GETKILLCNT) {
		return new Integer(repl.getInt());
		}
		return null;
		}

		@GuardedBy("sLmkdSocketLock")
		private static boolean openLmkdSocketLS() {
		boolean onLmkdConnect(OutputStream ostream) {
		try {
		sLmkdSocket = new LocalSocket(LocalSocket.SOCKET_SEQPACKET);
		sLmkdSocket.connect(
		new LocalSocketAddress("lmkd",
		LocalSocketAddress.Namespace.RESERVED));
		sLmkdOutputStream = sLmkdSocket.getOutputStream();
		sLmkdInputStream = sLmkdSocket.getInputStream();
		} catch (IOException ex) {
		Slog.w(TAG, "lowmemorykiller daemon socket open failed");
		sLmkdSocket = null;
		return false;
		// Purge any previously registered pids
		ByteBuffer buf = ByteBuffer.allocate(4);
		buf.putInt(LMK_PROCPURGE);
		ostream.write(buf.array(), 0, buf.position());
		if (mOomLevelsSet) {
		// Reset oom_adj levels
		buf = ByteBuffer.allocate(4 * (2 * mOomAdj.length + 1));
		buf.putInt(LMK_TARGET);
		for (int i = 0; i < mOomAdj.length; i++) {
		buf.putInt((mOomMinFree[i] * 1024) / PAGE_SIZE);
		buf.putInt(mOomAdj[i]);
		}

		return true;
		ostream.write(buf.array(), 0, buf.position());
		}

		// Never call directly, use writeLmkd() instead
		@GuardedBy("sLmkdSocketLock")
		private static boolean writeLmkdCommandLS(ByteBuffer buf) {
		try {
		sLmkdOutputStream.write(buf.array(), 0, buf.position());
		} catch (IOException ex) {
		Slog.w(TAG, "Error writing to lowmemorykiller socket");
		IoUtils.closeQuietly(sLmkdSocket);
		sLmkdSocket = null;
		return false;
		}
		return true;
		}

		// Never call directly, use writeLmkd() instead
		@GuardedBy("sLmkdSocketLock")
		private static boolean readLmkdReplyLS(ByteBuffer buf) {
		int len;
		try {
		len = sLmkdInputStream.read(buf.array(), 0, buf.array().length);
		if (len == buf.array().length) {
		return true;
		}
		} catch (IOException ex) {
		Slog.w(TAG, "Error reading from lowmemorykiller socket");
		}
		private static boolean writeLmkd(ByteBuffer buf, ByteBuffer repl) {
		if (!sLmkdConnection.isConnected()) {
		// try to connect immediately and then keep retrying
		sKillHandler.sendMessage(
		sKillHandler.obtainMessage(KillHandler.LMDK_RECONNECT_MSG));

		IoUtils.closeQuietly(sLmkdSocket);
		sLmkdSocket = null;
		// wait for connection retrying 3 times (up to 3 seconds)
		if (!sLmkdConnection.waitForConnection(3 * LMDK_RECONNECT_DELAY_MS)) {
		return false;
		}

		private static boolean writeLmkd(ByteBuffer buf, ByteBuffer repl) {
		synchronized (sLmkdSocketLock) {
		for (int i = 0; i < 3; i++) {
		if (sLmkdSocket == null) {
		if (openLmkdSocketLS() == false) {
		try {
		Thread.sleep(1000);
		} catch (InterruptedException ie) {
		}
		continue;
		}

		// Purge any previously registered pids
		ByteBuffer purge_buf = ByteBuffer.allocate(4);
		purge_buf.putInt(LMK_PROCPURGE);
		if (writeLmkdCommandLS(purge_buf) == false) {
		// Write failed, skip the rest and retry
		continue;
		}
		}
		if (writeLmkdCommandLS(buf) && (repl == null \|\| readLmkdReplyLS(repl))) {
		return true;
		}
		}
		}
		return false;
		return sLmkdConnection.exchange(buf, repl);
		}

		static void killProcessGroup(int uid, int pid) {