Merge "[KA02.5] Use binder thread and executor to invoke callback"

6 files changed, 179 insertions, 141 deletions

diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 2a357ff2bcbb..d08379fab047 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -38,7 +38,6 @@ import android.os.Build;
 import android.os.Build.VERSION_CODES;
 import android.os.Bundle;
 import android.os.Handler;
-import android.os.HandlerThread;
 import android.os.IBinder;
 import android.os.INetworkActivityListener;
 import android.os.INetworkManagementService;
@@ -75,6 +74,9 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.RejectedExecutionException;
 
 /**
  * Class that answers queries about the state of network connectivity. It also
@@ -1813,23 +1815,26 @@ public class ConnectivityManager {
         public static final int MIN_INTERVAL = 10;
 
         private final Network mNetwork;
-        private final PacketKeepaliveCallback mCallback;
-        private final Looper mLooper;
-        private final Messenger mMessenger;
+        private final ISocketKeepaliveCallback mCallback;
+        private final ExecutorService mExecutor;
 
         private volatile Integer mSlot;
 
-        void stopLooper() {
-            mLooper.quit();
-        }
-
         @UnsupportedAppUsage
         public void stop() {
             try {
-                mService.stopKeepalive(mNetwork, mSlot);
-            } catch (RemoteException e) {
-                Log.e(TAG, "Error stopping packet keepalive: ", e);
-                stopLooper();
+                mExecutor.execute(() -> {
+                    try {
+                        if (mSlot != null) {
+                            mService.stopKeepalive(mNetwork, mSlot);
+                        }
+                    } catch (RemoteException e) {
+                        Log.e(TAG, "Error stopping packet keepalive: ", e);
+                        throw e.rethrowFromSystemServer();
+                    }
+                });
+            } catch (RejectedExecutionException e) {
+                // The internal executor has already stopped due to previous event.
             }
         }
 
@@ -1837,40 +1842,43 @@ public class ConnectivityManager {
             Preconditions.checkNotNull(network, "network cannot be null");
             Preconditions.checkNotNull(callback, "callback cannot be null");
             mNetwork = network;
-            mCallback = callback;
-            HandlerThread thread = new HandlerThread(TAG);
-            thread.start();
-            mLooper = thread.getLooper();
-            mMessenger = new Messenger(new Handler(mLooper) {
+            mExecutor = Executors.newSingleThreadExecutor();
+            mCallback = new ISocketKeepaliveCallback.Stub() {
                 @Override
-                public void handleMessage(Message message) {
-                    switch (message.what) {
-                        case NetworkAgent.EVENT_SOCKET_KEEPALIVE:
-                            int error = message.arg2;
-                            try {
-                                if (error == SUCCESS) {
-                                    if (mSlot == null) {
-                                        mSlot = message.arg1;
-                                        mCallback.onStarted();
-                                    } else {
-                                        mSlot = null;
-                                        stopLooper();
-                                        mCallback.onStopped();
-                                    }
-                                } else {
-                                    stopLooper();
-                                    mCallback.onError(error);
-                                }
-                            } catch (Exception e) {
-                                Log.e(TAG, "Exception in keepalive callback(" + error + ")", e);
-                            }
-                            break;
-                        default:
-                            Log.e(TAG, "Unhandled message " + Integer.toHexString(message.what));
-                            break;
-                    }
+                public void onStarted(int slot) {
+                    Binder.withCleanCallingIdentity(() ->
+                            mExecutor.execute(() -> {
+                                mSlot = slot;
+                                callback.onStarted();
+                            }));
+                }
+
+                @Override
+                public void onStopped() {
+                    Binder.withCleanCallingIdentity(() ->
+                            mExecutor.execute(() -> {
+                                mSlot = null;
+                                callback.onStopped();
+                            }));
+                    mExecutor.shutdown();
+                }
+
+                @Override
+                public void onError(int error) {
+                    Binder.withCleanCallingIdentity(() ->
+                            mExecutor.execute(() -> {
+                                mSlot = null;
+                                callback.onError(error);
+                            }));
+                    mExecutor.shutdown();
                 }
-            });
+
+                @Override
+                public void onDataReceived() {
+                    // PacketKeepalive is only used for Nat-T keepalive and as such does not invoke
+                    // this callback when data is received.
+                }
+            };
         }
     }
 
@@ -1887,12 +1895,11 @@ public class ConnectivityManager {
             InetAddress srcAddr, int srcPort, InetAddress dstAddr) {
         final PacketKeepalive k = new PacketKeepalive(network, callback);
         try {
-            mService.startNattKeepalive(network, intervalSeconds, k.mMessenger, new Binder(),
+            mService.startNattKeepalive(network, intervalSeconds, k.mCallback,
                     srcAddr.getHostAddress(), srcPort, dstAddr.getHostAddress());
         } catch (RemoteException e) {
             Log.e(TAG, "Error starting packet keepalive: ", e);
-            k.stopLooper();
-            return null;
+            throw e.rethrowFromSystemServer();
         }
         return k;
     }
diff --git a/core/java/android/net/IConnectivityManager.aidl b/core/java/android/net/IConnectivityManager.aidl
index 403b44d6d7d7..540ef89f3a90 100644
--- a/core/java/android/net/IConnectivityManager.aidl
+++ b/core/java/android/net/IConnectivityManager.aidl
@@ -27,6 +27,7 @@ import android.net.NetworkMisc;
 import android.net.NetworkQuotaInfo;
 import android.net.NetworkRequest;
 import android.net.NetworkState;
+import android.net.ISocketKeepaliveCallback;
 import android.net.ProxyInfo;
 import android.os.Bundle;
 import android.os.IBinder;
@@ -194,15 +195,15 @@ interface IConnectivityManager
 
     void factoryReset();
 
-    void startNattKeepalive(in Network network, int intervalSeconds, in Messenger messenger,
-            in IBinder binder, String srcAddr, int srcPort, String dstAddr);
+    void startNattKeepalive(in Network network, int intervalSeconds,
+            in ISocketKeepaliveCallback cb, String srcAddr, int srcPort, String dstAddr);
 
     void startNattKeepaliveWithFd(in Network network, in FileDescriptor fd, int resourceId,
-            int intervalSeconds, in Messenger messenger, in IBinder binder, String srcAddr,
+            int intervalSeconds, in ISocketKeepaliveCallback cb, String srcAddr,
             String dstAddr);
 
     void startTcpKeepalive(in Network network, in FileDescriptor fd, int intervalSeconds,
-            in Messenger messenger, in IBinder binder);
+            in ISocketKeepaliveCallback cb);
 
     void stopKeepalive(in Network network, int slot);
 
diff --git a/core/java/android/net/ISocketKeepaliveCallback.aidl b/core/java/android/net/ISocketKeepaliveCallback.aidl
new file mode 100644
index 000000000000..020fbcacbfef
--- /dev/null
+++ b/core/java/android/net/ISocketKeepaliveCallback.aidl
@@ -0,0 +1,34 @@
+/**
+ * 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 android.net;
+
+/**
+ * Callback to provide status changes of keepalive offload.
+ *
+ * @hide
+ */
+oneway interface ISocketKeepaliveCallback
+{
+    /** The keepalive was successfully started. */
+    void onStarted(int slot);
+    /** The keepalive was successfully stopped. */
+    void onStopped();
+    /** The keepalive was stopped because of an error. */
+    void onError(int error);
+    /** The keepalive on a TCP socket was stopped because the socket received data. */
+    void onDataReceived();
+}
diff --git a/core/java/android/net/NattSocketKeepalive.java b/core/java/android/net/NattSocketKeepalive.java
index 88631aea3a88..84da294f8940 100644
--- a/core/java/android/net/NattSocketKeepalive.java
+++ b/core/java/android/net/NattSocketKeepalive.java
@@ -17,7 +17,6 @@
 package android.net;
 
 import android.annotation.NonNull;
-import android.os.Binder;
 import android.os.RemoteException;
 import android.util.Log;
 
@@ -52,24 +51,30 @@ public final class NattSocketKeepalive extends SocketKeepalive {
 
     @Override
     void startImpl(int intervalSec) {
-        try {
-            mService.startNattKeepaliveWithFd(mNetwork, mFd, mResourceId, intervalSec, mMessenger,
-                    new Binder(), mSource.getHostAddress(), mDestination.getHostAddress());
-        } catch (RemoteException e) {
-            Log.e(TAG, "Error starting packet keepalive: ", e);
-            stopLooper();
-        }
+        mExecutor.execute(() -> {
+            try {
+                mService.startNattKeepaliveWithFd(mNetwork, mFd, mResourceId, intervalSec,
+                        mCallback,
+                        mSource.getHostAddress(), mDestination.getHostAddress());
+            } catch (RemoteException e) {
+                Log.e(TAG, "Error starting socket keepalive: ", e);
+                throw e.rethrowFromSystemServer();
+            }
+        });
     }
 
     @Override
     void stopImpl() {
-        try {
-            if (mSlot != null) {
-                mService.stopKeepalive(mNetwork, mSlot);
+        mExecutor.execute(() -> {
+            try {
+                if (mSlot != null) {
+                    mService.stopKeepalive(mNetwork, mSlot);
+                }
+            } catch (RemoteException e) {
+                Log.e(TAG, "Error stopping socket keepalive: ", e);
+                throw e.rethrowFromSystemServer();
             }
-        } catch (RemoteException e) {
-            Log.e(TAG, "Error stopping packet keepalive: ", e);
-            stopLooper();
-        }
+        });
+
     }
 }
diff --git a/core/java/android/net/SocketKeepalive.java b/core/java/android/net/SocketKeepalive.java
index 07728beb9c64..0e768dfc8eb9 100644
--- a/core/java/android/net/SocketKeepalive.java
+++ b/core/java/android/net/SocketKeepalive.java
@@ -20,13 +20,8 @@ import android.annotation.IntDef;
 import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
-import android.os.Handler;
-import android.os.HandlerThread;
-import android.os.Looper;
-import android.os.Message;
-import android.os.Messenger;
-import android.os.Process;
-import android.util.Log;
+import android.os.Binder;
+import android.os.RemoteException;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -152,10 +147,9 @@ public abstract class SocketKeepalive implements AutoCloseable {
 
     @NonNull final IConnectivityManager mService;
     @NonNull final Network mNetwork;
-    @NonNull private final Executor mExecutor;
-    @NonNull private final SocketKeepalive.Callback mCallback;
-    @NonNull private final Looper mLooper;
-    @NonNull final Messenger mMessenger;
+    @NonNull final Executor mExecutor;
+    @NonNull final ISocketKeepaliveCallback mCallback;
+    // TODO: remove slot since mCallback could be used to identify which keepalive to stop.
     @Nullable Integer mSlot;
 
     SocketKeepalive(@NonNull IConnectivityManager service, @NonNull Network network,
@@ -163,53 +157,53 @@ public abstract class SocketKeepalive implements AutoCloseable {
         mService = service;
         mNetwork = network;
         mExecutor = executor;
-        mCallback = callback;
-        // TODO: 1. Use other thread modeling instead of create one thread for every instance to
-        //          reduce the memory cost.
-        //       2. support restart.
-        //       3. Fix race condition which caused by rapidly start and stop.
-        HandlerThread thread = new HandlerThread(TAG, Process.THREAD_PRIORITY_BACKGROUND
-                + Process.THREAD_PRIORITY_LESS_FAVORABLE);
-        thread.start();
-        mLooper = thread.getLooper();
-        mMessenger = new Messenger(new Handler(mLooper) {
+        mCallback = new ISocketKeepaliveCallback.Stub() {
             @Override
-            public void handleMessage(Message message) {
-                switch (message.what) {
-                    case NetworkAgent.EVENT_SOCKET_KEEPALIVE:
-                        final int status = message.arg2;
-                        try {
-                            if (status == SUCCESS) {
-                                if (mSlot == null) {
-                                    mSlot = message.arg1;
-                                    mExecutor.execute(() -> mCallback.onStarted());
-                                } else {
-                                    mSlot = null;
-                                    stopLooper();
-                                    mExecutor.execute(() -> mCallback.onStopped());
-                                }
-                            } else if (status == DATA_RECEIVED) {
-                                stopLooper();
-                                mExecutor.execute(() -> mCallback.onDataReceived());
-                            } else {
-                                stopLooper();
-                                mExecutor.execute(() -> mCallback.onError(status));
-                            }
-                        } catch (Exception e) {
-                            Log.e(TAG, "Exception in keepalive callback(" + status + ")", e);
-                        }
-                        break;
-                    default:
-                        Log.e(TAG, "Unhandled message " + Integer.toHexString(message.what));
-                        break;
-                }
+            public void onStarted(int slot) {
+                Binder.withCleanCallingIdentity(() ->
+                        mExecutor.execute(() -> {
+                            mSlot = slot;
+                            callback.onStarted();
+                        }));
             }
-        });
+
+            @Override
+            public void onStopped() {
+                Binder.withCleanCallingIdentity(() ->
+                        executor.execute(() -> {
+                            mSlot = null;
+                            callback.onStopped();
+                        }));
+            }
+
+            @Override
+            public void onError(int error) {
+                Binder.withCleanCallingIdentity(() ->
+                        executor.execute(() -> {
+                            mSlot = null;
+                            callback.onError(error);
+                        }));
+            }
+
+            @Override
+            public void onDataReceived() {
+                Binder.withCleanCallingIdentity(() ->
+                        executor.execute(() -> {
+                            mSlot = null;
+                            callback.onDataReceived();
+                        }));
+            }
+        };
     }
 
     /**
      * Request that keepalive be started with the given {@code intervalSec}. See
-     * {@link SocketKeepalive}.
+     * {@link SocketKeepalive}. If the remote binder dies, or the binder call throws an exception
+     * when invoking start or stop of the {@link SocketKeepalive}, a {@link RemoteException} will be
+     * thrown into the {@code executor}. This is typically not important to catch because the remote
+     * party is the system, so if it is not in shape to communicate through binder the system is
+     * probably going down anyway. If the caller cares regardless, it can use a custom
+     * {@link Executor} to catch the {@link RemoteException}.
      *
      * @param intervalSec The target interval in seconds between keepalive packet transmissions.
      *                    The interval should be between 10 seconds and 3600 seconds, otherwise
@@ -222,12 +216,6 @@ public abstract class SocketKeepalive implements AutoCloseable {
 
     abstract void startImpl(int intervalSec);
 
-    /** @hide */
-    protected void stopLooper() {
-        // TODO: remove this after changing thread modeling.
-        mLooper.quit();
-    }
-
     /**
      * Requests that keepalive be stopped. The application must wait for {@link Callback#onStopped}
      * before using the object. See {@link SocketKeepalive}.
@@ -245,7 +233,6 @@ public abstract class SocketKeepalive implements AutoCloseable {
     @Override
     public final void close() {
         stop();
-        stopLooper();
     }
 
     /**
@@ -259,7 +246,8 @@ public abstract class SocketKeepalive implements AutoCloseable {
         public void onStopped() {}
         /** An error occurred. */
         public void onError(@ErrorCode int error) {}
-        /** The keepalive on a TCP socket was stopped because the socket received data. */
+        /** The keepalive on a TCP socket was stopped because the socket received data. This is
+         * never called for UDP sockets. */
         public void onDataReceived() {}
     }
 }
diff --git a/core/java/android/net/TcpSocketKeepalive.java b/core/java/android/net/TcpSocketKeepalive.java
index f691a0d24344..26cc8ff181b2 100644
--- a/core/java/android/net/TcpSocketKeepalive.java
+++ b/core/java/android/net/TcpSocketKeepalive.java
@@ -17,7 +17,6 @@
 package android.net;
 
 import android.annotation.NonNull;
-import android.os.Binder;
 import android.os.RemoteException;
 import android.util.Log;
 
@@ -56,24 +55,28 @@ final class TcpSocketKeepalive extends SocketKeepalive {
      */
     @Override
     void startImpl(int intervalSec) {
-        try {
-            final FileDescriptor fd = mSocket.getFileDescriptor$();
-            mService.startTcpKeepalive(mNetwork, fd, intervalSec, mMessenger, new Binder());
-        } catch (RemoteException e) {
-            Log.e(TAG, "Error starting packet keepalive: ", e);
-            stopLooper();
-        }
+        mExecutor.execute(() -> {
+            try {
+                final FileDescriptor fd = mSocket.getFileDescriptor$();
+                mService.startTcpKeepalive(mNetwork, fd, intervalSec, mCallback);
+            } catch (RemoteException e) {
+                Log.e(TAG, "Error starting packet keepalive: ", e);
+                throw e.rethrowFromSystemServer();
+            }
+        });
     }
 
     @Override
     void stopImpl() {
-        try {
-            if (mSlot != null) {
-                mService.stopKeepalive(mNetwork, mSlot);
+        mExecutor.execute(() -> {
+            try {
+                if (mSlot != null) {
+                    mService.stopKeepalive(mNetwork, mSlot);
+                }
+            } catch (RemoteException e) {
+                Log.e(TAG, "Error stopping packet keepalive: ", e);
+                throw e.rethrowFromSystemServer();
             }
-        } catch (RemoteException e) {
-            Log.e(TAG, "Error stopping packet keepalive: ", e);
-            stopLooper();
-        }
+        });
     }
 }