Merge changes from topic "lmkd_async_msg"

am: f802ecca30

Change-Id: I105214f7157b680bce028b12a8f437505907a535

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

@@ -44,7 +44,7 @@ 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;
+    private static final int LMKD_REPLY_MAX_SIZE = 12;
 
     // connection listener interface
     interface LmkdConnectionListener {
@@ -62,6 +62,15 @@ public class LmkdConnection {
          */
         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;
@@ -185,17 +194,17 @@ public class LmkdConnection {
                         mReplyBuf.rewind();
                         // wakeup the waiting thread
                         mReplyBufLock.notifyAll();
-                    } else {
+                    } else if (!mListener.handleUnsolicitedMessage(mInputBuf, len)) {
-                        // received asynchronous or unexpected packet
+                        // received unexpected packet
                         // treat this as an error
                         mReplyBuf = null;
                         mReplyBufLock.notifyAll();
-                        Slog.e(TAG, "Received unexpected packet from lmkd");
+                        Slog.e(TAG, "Received an unexpected packet from lmkd");
                     }
-                } else {
+                } else if (!mListener.handleUnsolicitedMessage(mInputBuf, len)) {
                     // received asynchronous communication from lmkd
-                    // we don't support this yet
+                    // but we don't recognize it.
-                    Slog.w(TAG, "Received an asynchronous packet from lmkd");
+                    Slog.w(TAG, "Received an unexpected packet from lmkd");
                 }
             }
         }

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

@@ -253,14 +253,16 @@ public final class ProcessList {
     // LMK_PROCREMOVE <pid>
     // 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 LMDK_RECONNECT_DELAY_MS = 1000;
+    private static final long LMKD_RECONNECT_DELAY_MS = 1000;
 
     ActivityManagerService mService = null;
 
@@ -355,6 +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.
      */
@@ -373,6 +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;
@@ -525,7 +540,8 @@ public final class ProcessList {
 
     final class KillHandler extends Handler {
         static final int KILL_PROCESS_GROUP_MSG = 4000;
-        static final int LMDK_RECONNECT_MSG = 4001;
+        static final int LMKD_RECONNECT_MSG = 4001;
+        static final int LMKD_PROC_KILLED_MSG = 4002;
 
         public KillHandler(Looper looper) {
             super(looper, null, true);
@@ -539,15 +555,18 @@ public final class ProcessList {
                     Process.killProcessGroup(msg.arg1 /* uid */, msg.arg2 /* pid */);
                     Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
                     break;
-                case LMDK_RECONNECT_MSG:
+                case LMKD_RECONNECT_MSG:
                     if (!sLmkdConnection.connect()) {
                         Slog.i(TAG, "Failed to connect to lmkd, retry after "
-                                + LMDK_RECONNECT_DELAY_MS + " ms");
+                                + LMKD_RECONNECT_DELAY_MS + " ms");
-                        // retry after LMDK_RECONNECT_DELAY_MS
+                        // retry after LMKD_RECONNECT_DELAY_MS
                         sKillHandler.sendMessageDelayed(sKillHandler.obtainMessage(
-                                KillHandler.LMDK_RECONNECT_MSG), LMDK_RECONNECT_DELAY_MS);
+                                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);
@@ -587,7 +606,7 @@ public final class ProcessList {
                             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);
+                                    KillHandler.LMKD_RECONNECT_MSG), LMKD_RECONNECT_DELAY_MS);
                         }
                         @Override
                         public boolean isReplyExpected(ByteBuffer replyBuf,
@@ -597,6 +616,26 @@ public final class ProcessList {
                             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;
+                            }
+                        }
                     }
             );
         }
@@ -1279,10 +1318,10 @@ public final class ProcessList {
         if (!sLmkdConnection.isConnected()) {
             // try to connect immediately and then keep retrying
             sKillHandler.sendMessage(
-                    sKillHandler.obtainMessage(KillHandler.LMDK_RECONNECT_MSG));
+                    sKillHandler.obtainMessage(KillHandler.LMKD_RECONNECT_MSG));
 
             // wait for connection retrying 3 times (up to 3 seconds)
-            if (!sLmkdConnection.waitForConnection(3 * LMDK_RECONNECT_DELAY_MS)) {
+            if (!sLmkdConnection.waitForConnection(3 * LMKD_RECONNECT_DELAY_MS)) {
                 return false;
             }
         }
@@ -3192,4 +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));
+            }
+        }
+    }
 }