Moving BindingManager and ChildProcessConnection to base/.

base/android/java/src/org/chromium/base/process_launcher/BaseChildProcessConnection.java

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-package org.chromium.content.browser;
+package org.chromium.base.process_launcher;
 
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.content.ServiceConnection;
 import android.content.pm.PackageManager;
 import android.content.pm.ServiceInfo;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.Handler;
 import android.os.IBinder;
+import android.os.Looper;
 import android.os.RemoteException;
 
 import org.chromium.base.Log;
 import org.chromium.base.TraceEvent;
 import org.chromium.base.VisibleForTesting;
-import org.chromium.base.process_launcher.ChildProcessCreationParams;
-import org.chromium.base.process_launcher.FileDescriptorInfo;
-import org.chromium.base.process_launcher.ICallbackInt;
-import org.chromium.base.process_launcher.IChildProcessService;
 
 import java.io.IOException;
 
 import javax.annotation.Nullable;
 
 /**
  * Manages a connection between the browser activity and a child service.
+ * Most calls should happen on the connection's thread, the one specified in the constructor.
  */
 public abstract class BaseChildProcessConnection {
     private static final String TAG = "BaseChildProcessConn";
 
     /**
      * Used to notify the consumer about disconnection of the service. This callback is provided
      * earlier than ConnectionCallbacks below, as a child process might die before the connection is
      * fully set up.
      */
-    interface DeathCallback {
-        // Called on Launcher thread.
+    public interface DeathCallback {
+        // Called on the connection's thread.
         void onChildProcessDied(BaseChildProcessConnection connection);
     }
 
     /**
      * Used to notify the consumer about the process start. These callbacks will be invoked before
      * the ConnectionCallbacks.
      */
-    interface StartCallback {
+    public interface StartCallback {
         /**
          * Called when the child process has successfully started and is ready for connection
          * setup.
          */
         void onChildStarted();
 
         /**
          * Called when the child process failed to start. This can happen if the process is already
          * in use by another client.
          */
         void onChildStartFailed();
     }
 
     /**
-     * Used to notify the consumer about the connection being established.
+     * Used to notify the consumer about the connection being setup and established.
      */
-    interface ConnectionCallback {
+    public interface ConnectionCallback {
+        /**
+         * Called before the connection to the service is established. This gives clients an
+         * opportunity to add custom parameters to params which is passed on to the service.
+         * @param params a bundle passed to the service.
+         */
+        void onConnectionSetup(Bundle params);
+
         /**
          * Called when the connection to the service is established.
-         * @param connecion the connection object to the child process
+         * @param connection the connection object to the child process
          */
         void onConnected(BaseChildProcessConnection connection);
     }
 
-    /** Used to create specialization connection instances. */
-    interface Factory {
-        BaseChildProcessConnection create(Context context, int number, boolean sandboxed,
-                DeathCallback deathCallback, String serviceClassName,
+    /** Used to create specialization of connection instances. */
+    public interface Factory {
+        BaseChildProcessConnection create(Handler handler, Context context, int number,
+                boolean sandboxed, DeathCallback deathCallback, String serviceClassName,
                 Bundle childProcessCommonParameters, ChildProcessCreationParams creationParams);
     }
 
     /** Interface representing a connection to the Android service. Can be mocked in unit-tests. */
     protected interface ChildServiceConnection {
         boolean bind();
         void unbind();
         boolean isBound();
     }
 
@@ skipping 41 matching lines @@
             }
         }
 
         @Override
         public boolean isBound() {
             return mBound;
         }
 
         @Override
         public void onServiceConnected(ComponentName className, final IBinder service) {
-            LauncherThread.post(new Runnable() {
+            mHandler.post(new Runnable() {
                 @Override
                 public void run() {
-                    BaseChildProcessConnection.this.onServiceConnectedOnLauncherThread(service);
+                    BaseChildProcessConnection.this.onServiceConnected(service);
                 }
             });
         }
 
         // Called on the main thread to notify that the child service did not disconnect gracefully.
         @Override
         public void onServiceDisconnected(ComponentName className) {
-            LauncherThread.post(new Runnable() {
+            mHandler.post(new Runnable() {
                 @Override
                 public void run() {
-                    BaseChildProcessConnection.this.onServiceDisconnectedOnLauncherThread();
+                    BaseChildProcessConnection.this.onServiceDisconnected();
                 }
             });
         }
     }
 
     // Caches whether non-sandboxed and sandboxed services require an extra
     // binding flag provided via ChildProcessCreationParams.
     // TODO(mnaganov): Get rid of it after the release of the next Android SDK.
     private static Boolean sNeedsExtrabindFlags[] = new Boolean[2];
     private final Context mContext;
@@ skipping 15 matching lines @@
         final IBinder mCallback;
 
         ConnectionParams(
                 String[] commandLine, FileDescriptorInfo[] filesToBeMapped, IBinder callback) {
             mCommandLine = commandLine;
             mFilesToBeMapped = filesToBeMapped;
             mCallback = callback;
         }
     }
 
+    // The handler for the thread the connection should be accessed on.
+    private final Handler mHandler;
+
     // This is set in start() and is used in onServiceConnected().
     private StartCallback mStartCallback;
 
     // This is set in setupConnection() and is later used in doConnectionSetupLocked(), after which
     // the variable is cleared. Therefore this is only valid while the connection is being set up.
     private ConnectionParams mConnectionParams;
 
     // Callback provided in setupConnection() that will communicate the result to the caller. This
     // has to be called exactly once after setupConnection(), even if setup fails, so that the
     // caller can free up resources associated with the setup attempt. This is set to null after the
     // call.
     private ConnectionCallback mConnectionCallback;
 
     private IChildProcessService mService;
 
     // Set to true when the service connection callback runs. This differs from
     // mServiceConnectComplete, which tracks that the connection completed successfully.
     private boolean mDidOnServiceConnected;
 
     // Set to true when the service connected successfully.
     private boolean mServiceConnectComplete;
 
     // Set to true when the service disconnects, as opposed to being properly closed. This happens
     // when the process crashes or gets killed by the system out-of-memory killer.
     private boolean mServiceDisconnected;
 
     // Process ID of the corresponding child process.
     private int mPid;
 
-    protected BaseChildProcessConnection(Context context, int number, boolean sandboxed,
-            DeathCallback deathCallback, String serviceClassName,
+    protected BaseChildProcessConnection(Handler handler, Context context, int number,
+            boolean sandboxed, DeathCallback deathCallback, String serviceClassName,
             Bundle childProcessCommonParameters, ChildProcessCreationParams creationParams) {
-        assert LauncherThread.runningOnLauncherThread();
+        mHandler = handler;
         mContext = context;
         mServiceNumber = number;
         mSandboxed = sandboxed;
         mDeathCallback = deathCallback;
         String packageName =
                 creationParams != null ? creationParams.getPackageName() : context.getPackageName();
         mServiceName = new ComponentName(packageName, serviceClassName + mServiceNumber);
         mChildProcessCommonParameters = childProcessCommonParameters;
         mCreationParams = creationParams;
     }
 
     public final Context getContext() {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         return mContext;
     }
 
     public final int getServiceNumber() {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         return mServiceNumber;
     }
 
     public final boolean isSandboxed() {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         return mSandboxed;
     }
 
     public final String getPackageName() {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         return mCreationParams != null ? mCreationParams.getPackageName()
                                        : mContext.getPackageName();
     }
 
     public final ChildProcessCreationParams getCreationParams() {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         return mCreationParams;
     }
 
     public final IChildProcessService getService() {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         return mService;
     }
 
     public final ComponentName getServiceName() {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         return mServiceName;
     }
 
     /**
      * @return the connection pid, or 0 if not yet connected
      */
     public int getPid() {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         return mPid;
     }
 
     /**
      * Starts a connection to an IChildProcessService. This must be followed by a call to
      * setupConnection() to setup the connection parameters. start() and setupConnection() are
      * separate to allow to pass whatever parameters are available in start(), and complete the
      * remainder later while reducing the connection setup latency.
      * @param startCallback (optional) callback when the child process starts or fails to start.
      */
     public void start(StartCallback startCallback) {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         try {
             TraceEvent.begin("BaseChildProcessConnection.start");
-            assert LauncherThread.runningOnLauncherThread();
+            checkOnValidThread();

[boliu, 2017/04/28 17:16:27]

no need to repeat this :p

             assert mConnectionParams
                     == null
                     : "setupConnection() called before start() in BaseChildProcessConnection.";
 
             mStartCallback = startCallback;
 
             if (!bind()) {
                 Log.e(TAG, "Failed to establish the service connection.");
                 // We have to notify the caller so that they can free-up associated resources.
                 // TODO(ppi): Can we hard-fail here?
                 mDeathCallback.onChildProcessDied(BaseChildProcessConnection.this);
             }
         } finally {
             TraceEvent.end("BaseChildProcessConnection.start");
         }
     }
 
     /**
      * Setups the connection after it was started with start().
      * @param commandLine (optional) will be ignored if the command line was already sent in start()
      * @param filesToBeMapped a list of file descriptors that should be registered
      * @param callback optional client specified callbacks that the child can use to communicate
      *                 with the parent process
      * @param connectionCallback will be called exactly once after the connection is set up or the
      *                           setup fails
      */
     public void setupConnection(String[] commandLine, FileDescriptorInfo[] filesToBeMapped,
             @Nullable IBinder callback, ConnectionCallback connectionCallback) {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         assert mConnectionParams == null;
         if (mServiceDisconnected) {
             Log.w(TAG, "Tried to setup a connection that already disconnected.");
             connectionCallback.onConnected(null);
             return;
         }
         try {
             TraceEvent.begin("BaseChildProcessConnection.setupConnection");
             mConnectionCallback = connectionCallback;
             mConnectionParams = new ConnectionParams(commandLine, filesToBeMapped, callback);
             // Run the setup if the service is already connected. If not,
             // doConnectionSetupLocked() will be called from onServiceConnected().
             if (mServiceConnectComplete) {
                 doConnectionSetupLocked();
             }
         } finally {
             TraceEvent.end("BaseChildProcessConnection.setupConnection");
         }
     }
 
     /**
      * Terminates the connection to IChildProcessService, closing all bindings. It is safe to call
      * this multiple times.
      */
     public void stop() {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         unbind();
         mService = null;
         mConnectionParams = null;
     }
 
-    private void onServiceConnectedOnLauncherThread(IBinder service) {
-        assert LauncherThread.runningOnLauncherThread();
+    private void onServiceConnected(IBinder service) {
+        checkOnValidThread();
         // A flag from the parent class ensures we run the post-connection logic only once
         // (instead of once per each ChildServiceConnection).
         if (mDidOnServiceConnected) {
             return;
         }
         try {
             TraceEvent.begin(
                     "BaseChildProcessConnection.ChildServiceConnection.onServiceConnected");
             mDidOnServiceConnected = true;
             mService = IChildProcessService.Stub.asInterface(service);
@@ skipping 30 matching lines @@
             // Run the setup if the connection parameters have already been provided. If
             // not, doConnectionSetupLocked() will be called from setupConnection().
             if (mConnectionParams != null) {
                 doConnectionSetupLocked();
             }
         } finally {
             TraceEvent.end("BaseChildProcessConnection.ChildServiceConnection.onServiceConnected");
         }
     }
 
-    private void onServiceDisconnectedOnLauncherThread() {
-        assert LauncherThread.runningOnLauncherThread();
+    private void onServiceDisconnected() {
+        checkOnValidThread();
         // Ensure that the disconnection logic runs only once (instead of once per each
         // ChildServiceConnection).
         if (mServiceDisconnected) {
             return;
         }
         mServiceDisconnected = true;
         Log.w(TAG, "onServiceDisconnected (crash or killed by oom): pid=%d", mPid);
         stop(); // We don't want to auto-restart on crash. Let the browser do that.
         mDeathCallback.onChildProcessDied(BaseChildProcessConnection.this);
         // If we have a pending connection callback, we need to communicate the failure to
@@ skipping 18 matching lines @@
      * Called after the connection parameters have been set (in setupConnection()) *and* a
      * connection has been established (as signaled by onServiceConnected()). These two events can
      * happen in any order. Has to be called with mLock.
      */
     private void doConnectionSetupLocked() {
         try {
             TraceEvent.begin("BaseChildProcessConnection.doConnectionSetupLocked");
             assert mServiceConnectComplete && mService != null;
             assert mConnectionParams != null;
 
-            Bundle bundle = ChildProcessLauncher.createsServiceBundle(
-                    mConnectionParams.mCommandLine, mConnectionParams.mFilesToBeMapped);
+            Bundle bundle = new Bundle();
+            bundle.putStringArray(
+                    ChildProcessConstants.EXTRA_COMMAND_LINE, mConnectionParams.mCommandLine);
+            bundle.putParcelableArray(
+                    ChildProcessConstants.EXTRA_FILES, mConnectionParams.mFilesToBeMapped);
+
+            if (mConnectionCallback != null) {

[boliu, 2017/04/28 17:16:27]

is this check needed? should this be an assert instead?

+                mConnectionCallback.onConnectionSetup(bundle);
+            }
+
             ICallbackInt pidCallback = new ICallbackInt.Stub() {
                 @Override
                 public void call(final int pid) {
-                    LauncherThread.post(new Runnable() {
+                    mHandler.post(new Runnable() {
                         @Override
                         public void run() {
                             onSetupConnectionResult(pid);
                         }
                     });
                 }
             };
             try {
                 mService.setupConnection(bundle, pidCallback, mConnectionParams.mCallback);
             } catch (RemoteException re) {
@@ skipping 11 matching lines @@
         } finally {
             TraceEvent.end("BaseChildProcessConnection.doConnectionSetupLocked");
         }
     }
 
     /** Subclasses should implement this method to bind/unbind to the actual service. */
     protected abstract boolean bind();
     protected abstract void unbind();
 
     protected ChildServiceConnection createServiceConnection(int bindFlags) {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         return new ChildServiceConnectionImpl(bindFlags);
     }
 
     protected boolean shouldBindAsExportedService() {
-        assert LauncherThread.runningOnLauncherThread();
+        checkOnValidThread();
         return Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && getCreationParams() != null
                 && getCreationParams().getIsExternalService()
                 && isExportedService(isSandboxed(), getContext(), getServiceName());
     }
 
     private static boolean isExportedService(
             boolean inSandbox, Context context, ComponentName serviceName) {
         // Check for the cached value first. It is assumed that all pooled child services
         // have identical attributes in the manifest.
         final int arrayIndex = inSandbox ? 1 : 0;
         if (sNeedsExtrabindFlags[arrayIndex] != null) {
             return sNeedsExtrabindFlags[arrayIndex].booleanValue();
         }
         boolean result = false;
         try {
             PackageManager packageManager = context.getPackageManager();
             ServiceInfo serviceInfo = packageManager.getServiceInfo(serviceName, 0);
             result = serviceInfo.exported;
         } catch (PackageManager.NameNotFoundException e) {
             Log.e(TAG, "Could not retrieve info about service %s", serviceName, e);
         }
         sNeedsExtrabindFlags[arrayIndex] = Boolean.valueOf(result);
         return result;
     }
 
+    /** Checks whether the caller is running on the thread specified at creation time. */
+    protected final void checkOnValidThread() {
+        assert mHandler.getLooper() == Looper.myLooper();
+    }
+
     @VisibleForTesting
     public void crashServiceForTesting() throws RemoteException {
         mService.crashIntentionallyForTesting();
     }
 
     @VisibleForTesting
-    boolean isConnected() {
+    public boolean isConnected() {
         return mService != null;
     }
 }