diff --git a/services/core/java/com/android/server/am/LmkdConnection.java b/services/core/java/com/android/server/am/LmkdConnection.java
new file mode 100644
index 0000000000000..cacf6765a28e2
--- /dev/null
+++ b/services/core/java/com/android/server/am/LmkdConnection.java
@@ -0,0 +1,300 @@
+/*
+ * 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 = 12;
+
+ // 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);
+
+ /**
+ * Handle the received message if it's unsolicited.
+ *
+ * @param dataReceived The buffer holding received data
+ * @param receivedLen Size of the data received
+ * @return True if the message has been handled correctly, false otherwise.
+ */
+ boolean handleUnsolicitedMessage(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 if (!mListener.handleUnsolicitedMessage(mInputBuf, len)) {
+ // received unexpected packet
+ // treat this as an error
+ mReplyBuf = null;
+ mReplyBufLock.notifyAll();
+ Slog.e(TAG, "Received an unexpected packet from lmkd");
+ }
+ } else if (!mListener.handleUnsolicitedMessage(mInputBuf, len)) {
+ // received asynchronous communication from lmkd
+ // but we don't recognize it.
+ Slog.w(TAG, "Received an unexpected 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;
+ }
+}
diff --git a/services/core/java/com/android/server/am/ProcessList.java b/services/core/java/com/android/server/am/ProcessList.java
index f397a3243b2a2..3b8d39bf7a19b 100644
--- a/services/core/java/com/android/server/am/ProcessList.java
+++ b/services/core/java/com/android/server/am/ProcessList.java
@@ -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:
- *
- * - Methods suffixed with "LS" should be called within the {@link #sLmkdSocketLock} lock.
- *
*/
public final class ProcessList {
static final String TAG = TAG_WITH_CLASS_NAME ? "ProcessList" : TAG_AM;
@@ -263,11 +253,16 @@ public final class ProcessList {
// LMK_PROCREMOVE
// LMK_PROCPURGE
// LMK_GETKILLCNT
+ // LMK_PROCKILL
static final byte LMK_TARGET = 0;
static final byte LMK_PROCPRIO = 1;
static final byte LMK_PROCREMOVE = 2;
static final byte LMK_PROCPURGE = 3;
static final byte LMK_GETKILLCNT = 4;
+ static final byte LMK_PROCKILL = 5; // Note: this is an unsolicated command
+
+ // lmkd reconnect delay in msecs
+ private static final long LMKD_RECONNECT_DELAY_MS = 1000;
ActivityManagerService mService = null;
@@ -303,16 +298,9 @@ 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.
@@ -369,6 +357,12 @@ public final class ProcessList {
ActiveUids mActiveUids;
+ /**
+ * The listener who is intereted with the lmkd kills.
+ */
+ @GuardedBy("mService")
+ private LmkdKillListener mLmkdKillListener = null;
+
/**
* The currently running isolated processes.
*/
@@ -387,6 +381,13 @@ public final class ProcessList {
private PlatformCompat mPlatformCompat = null;
+ interface LmkdKillListener {
+ /**
+ * Called when there is a process kill by lmkd.
+ */
+ void onLmkdKillOccurred(int pid, int uid);
+ }
+
final class IsolatedUidRange {
@VisibleForTesting
public final int mFirstUid;
@@ -539,6 +540,8 @@ public final class ProcessList {
final class KillHandler extends Handler {
static final int KILL_PROCESS_GROUP_MSG = 4000;
+ static final int LMKD_RECONNECT_MSG = 4001;
+ static final int LMKD_PROC_KILLED_MSG = 4002;
public KillHandler(Looper looper) {
super(looper, null, true);
@@ -552,6 +555,18 @@ public final class ProcessList {
Process.killProcessGroup(msg.arg1 /* uid */, msg.arg2 /* pid */);
Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
break;
+ case LMKD_RECONNECT_MSG:
+ if (!sLmkdConnection.connect()) {
+ Slog.i(TAG, "Failed to connect to lmkd, retry after "
+ + LMKD_RECONNECT_DELAY_MS + " ms");
+ // retry after LMKD_RECONNECT_DELAY_MS
+ sKillHandler.sendMessageDelayed(sKillHandler.obtainMessage(
+ KillHandler.LMKD_RECONNECT_MSG), LMKD_RECONNECT_DELAY_MS);
+ }
+ break;
+ case LMKD_PROC_KILLED_MSG:
+ handleLmkdProcKilled(msg.arg1 /* pid */, msg.arg2 /* uid */);
+ break;
default:
super.handleMessage(msg);
@@ -579,6 +594,50 @@ 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.LMKD_RECONNECT_MSG), LMKD_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));
+ }
+
+ @Override
+ public boolean handleUnsolicitedMessage(ByteBuffer dataReceived,
+ int receivedLen) {
+ if (receivedLen < 4) {
+ return false;
+ }
+ switch (dataReceived.getInt(0)) {
+ case LMK_PROCKILL:
+ if (receivedLen != 12) {
+ return false;
+ }
+ sKillHandler.obtainMessage(KillHandler.LMKD_PROC_KILLED_MSG,
+ dataReceived.getInt(4), dataReceived.getInt(8))
+ .sendToTarget();
+ return true;
+ default:
+ return false;
+ }
+ }
+ }
+ );
}
}
@@ -684,6 +743,7 @@ 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 +1283,50 @@ 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;
- }
-
- return true;
- }
-
- // 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;
+ // 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]);
+ }
+ ostream.write(buf.array(), 0, buf.position());
}
} catch (IOException ex) {
- Slog.w(TAG, "Error reading from lowmemorykiller socket");
+ return false;
}
-
- IoUtils.closeQuietly(sLmkdSocket);
- sLmkdSocket = null;
- return false;
+ return true;
}
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;
- }
+ if (!sLmkdConnection.isConnected()) {
+ // try to connect immediately and then keep retrying
+ sKillHandler.sendMessage(
+ sKillHandler.obtainMessage(KillHandler.LMKD_RECONNECT_MSG));
- // 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;
- }
+ // wait for connection retrying 3 times (up to 3 seconds)
+ if (!sLmkdConnection.waitForConnection(3 * LMKD_RECONNECT_DELAY_MS)) {
+ return false;
}
}
- return false;
+
+ return sLmkdConnection.exchange(buf, repl);
}
static void killProcessGroup(int uid, int pid) {
@@ -3214,4 +3231,28 @@ public final class ProcessList {
mService.doStopUidLocked(uidRec.uid, uidRec);
}
}
+
+ void setLmkdKillListener(final LmkdKillListener listener) {
+ synchronized (mService) {
+ mLmkdKillListener = listener;
+ }
+ }
+
+ private void handleLmkdProcKilled(final int pid, final int uid) {
+ // Log only now
+ if (DEBUG_PROCESSES) {
+ Slog.i(TAG, "lmkd kill: pid=" + pid + " uid=" + uid);
+ }
+
+ if (mService == null) {
+ return;
+ }
+ // Notify any interesed party regarding the lmkd kills
+ synchronized (mService) {
+ final LmkdKillListener listener = mLmkdKillListener;
+ if (listener != null) {
+ mService.mHandler.post(()-> listener.onLmkdKillOccurred(pid, uid));
+ }
+ }
+ }
}