Refactoring ChildProcessConnection.

content/public/android/java/src/org/chromium/content/browser/BaseChildProcessConnection.java

Index: content/public/android/java/src/org/chromium/content/browser/BaseChildProcessConnection.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ChildProcessConnectionImpl.java b/content/public/android/java/src/org/chromium/content/browser/BaseChildProcessConnection.java
similarity index 61%
rename from content/public/android/java/src/org/chromium/content/browser/ChildProcessConnectionImpl.java
rename to content/public/android/java/src/org/chromium/content/browser/BaseChildProcessConnection.java
index 710741b69c86a045512bf88f0459e6b9fd7934e7..52bfe5e5a7876a9868afff7493a07b436c6e7a19 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ChildProcessConnectionImpl.java
+++ b/content/public/android/java/src/org/chromium/content/browser/BaseChildProcessConnection.java
@@ -26,97 +26,72 @@ import org.chromium.base.process_launcher.IChildProcessService;
 import java.io.IOException;
 
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
 
 /**
  * Manages a connection between the browser activity and a child service.
  */
-public class ChildProcessConnectionImpl implements ChildProcessConnection {
-    private final Context mContext;
-    private final int mServiceNumber;
-    private final boolean mInSandbox;
-    private final ChildProcessConnection.DeathCallback mDeathCallback;
-    private final ComponentName mServiceName;
-
-    // Synchronization: While most internal flow occurs on the UI thread, the public API
-    // (specifically start and stop) may be called from any thread, hence all entry point methods
-    // into the class are synchronized on the lock to protect access to these members.
-    private final Object mLock = new Object();
-    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;
-    // When the service disconnects (i.e. mServiceDisconnected is set to true), the status of the
-    // oom bindings is stashed here for future inspection.
-    private boolean mWasOomProtected;
-    private int mPid;  // Process ID of the corresponding child process.
-    // Initial binding protects the newly spawned process from being killed before it is put to use,
-    // it is maintained between calls to start() and removeInitialBinding().
-    private ChildServiceConnection mInitialBinding;
-    // Strong binding will make the service priority equal to the priority of the activity. We want
-    // the OS to be able to kill background renderers as it kills other background apps, so strong
-    // bindings are maintained only for services that are active at the moment (between
-    // addStrongBinding() and removeStrongBinding()).
-    private ChildServiceConnection mStrongBinding;
-    // Low priority binding maintained in the entire lifetime of the connection, i.e. between calls
-    // to start() and stop().
-    private ChildServiceConnection mWaivedBinding;
-    // Incremented on addStrongBinding(), decremented on removeStrongBinding().
-    private int mStrongBindingCount;
-    // Moderate binding will make the service priority equal to the priority of a visible process
-    // while the app is in the foreground. It will stay bound only while the app is in the
-    // foreground to protect a background process from the system out-of-memory killer.
-    private ChildServiceConnection mModerateBinding;
-
-    // Parameters passed to the child process through the service binding intent.
-    // If the service gets recreated by the framework the intent will be reused, so these parameters
-    // should be common to all processes of that type.
-    private final Bundle mChildProcessCommonParameters;
-
-    private final boolean mAlwaysInForeground;
-    private final ChildProcessCreationParams mCreationParams;
+public abstract class BaseChildProcessConnection {
+    private static final String TAG = "BaseChildProcessConn";
 
-    // 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 static final String TAG = "ChildProcessConnect";
-
-    private static class ConnectionParams {
-        final String[] mCommandLine;
-        final FileDescriptorInfo[] mFilesToBeMapped;
-        final IBinder mCallback;
-
-        ConnectionParams(
-                String[] commandLine, FileDescriptorInfo[] filesToBeMapped, IBinder callback) {
-            mCommandLine = commandLine;
-            mFilesToBeMapped = filesToBeMapped;
-            mCallback = callback;
-        }
+    /**
+     * 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.
+        void onChildProcessDied(BaseChildProcessConnection connection);
     }
 
-    // This is set in start() and is used in onServiceConnected().
-    private ChildProcessConnection.StartCallback mStartCallback;
+    /**
+     * Used to notify the consumer about the process start. These callbacks will be invoked before
+     * the ConnectionCallbacks.
+     */
+    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();
+    }
 
-    // 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;
+    /**
+     * Used to notify the consumer about the connection being established.
+     */
+    interface ConnectionCallback {
+        /**
+         * Called when the connection to the service is established.
+         * @param connecion the connection object to the child process
+         */
+        void onConnected(BaseChildProcessConnection connection);
+    }
 
-    // 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 ChildProcessConnection.ConnectionCallback mConnectionCallback;
+    /** Used to create specialization connection instances. */
+    interface Factory {
+        BaseChildProcessConnection create(Context context, int number, boolean sandboxed,
+                DeathCallback deathCallback, String serviceClassName,
+                Bundle childProcessCommonParameters, ChildProcessCreationParams creationParams);
+    }
 
-    private class ChildServiceConnection implements ServiceConnection {
-        private boolean mBound;
+    /** Interface representing a connection to the Android service. Can be mocked in unit-tests. */
+    protected interface ChildServiceConnection {
+        boolean bind();
+        void unbind();
+        boolean isBound();
+    }
 
+    /** Implementation of ChildServiceConnection that does connect to a service. */
+    protected class ChildServiceConnectionImpl
+            implements ChildServiceConnection, ServiceConnection {
         private final int mBindFlags;
+        private boolean mBound;
 
         private Intent createServiceBindIntent() {
             Intent intent = new Intent();
@@ -127,34 +102,37 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
             return intent;
         }
 
-        public ChildServiceConnection(int bindFlags) {
+        private ChildServiceConnectionImpl(int bindFlags) {
             mBindFlags = bindFlags;
         }
 
-        boolean bind() {
+        @Override
+        public boolean bind() {
             if (!mBound) {
                 try {
-                    TraceEvent.begin("ChildProcessConnectionImpl.ChildServiceConnection.bind");
+                    TraceEvent.begin("BaseChildProcessConnection.ChildServiceConnection.bind");
                     Intent intent = createServiceBindIntent();
                     if (mChildProcessCommonParameters != null) {
                         intent.putExtras(mChildProcessCommonParameters);
                     }
                     mBound = mContext.bindService(intent, this, mBindFlags);
                 } finally {
-                    TraceEvent.end("ChildProcessConnectionImpl.ChildServiceConnection.bind");
+                    TraceEvent.end("BaseChildProcessConnection.ChildServiceConnection.bind");
                 }
             }
             return mBound;
         }
 
-        void unbind() {
+        @Override
+        public void unbind() {
             if (mBound) {
                 mContext.unbindService(this);
                 mBound = false;
             }
         }
 
-        boolean isBound() {
+        @Override
+        public boolean isBound() {
             return mBound;
         }
 
@@ -163,7 +141,7 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
             LauncherThread.post(new Runnable() {
                 @Override
                 public void run() {
-                    ChildProcessConnectionImpl.this.onServiceConnectedOnLauncherThread(service);
+                    BaseChildProcessConnection.this.onServiceConnectedOnLauncherThread(service);
                 }
             });
         }
@@ -174,123 +152,178 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
             LauncherThread.post(new Runnable() {
                 @Override
                 public void run() {
-                    ChildProcessConnectionImpl.this.onServiceDisconnectedOnLauncherThread();
+                    BaseChildProcessConnection.this.onServiceDisconnectedOnLauncherThread();
                 }
             });
         }
     }
 
-    ChildProcessConnectionImpl(Context context, int number, boolean inSandbox,
-            ChildProcessConnection.DeathCallback deathCallback, String serviceClassName,
-            Bundle childProcessCommonParameters, boolean alwaysInForeground,
-            ChildProcessCreationParams creationParams) {
+    // 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;
+    private final int mServiceNumber;
+    private final boolean mSandboxed;
+    private final BaseChildProcessConnection.DeathCallback mDeathCallback;
+    private final ComponentName mServiceName;
+
+    // Parameters passed to the child process through the service binding intent.
+    // If the service gets recreated by the framework the intent will be reused, so these parameters
+    // should be common to all processes of that type.
+    private final Bundle mChildProcessCommonParameters;
+
+    private final ChildProcessCreationParams mCreationParams;
+
+    private static class ConnectionParams {
+        final String[] mCommandLine;
+        final FileDescriptorInfo[] mFilesToBeMapped;
+        final IBinder mCallback;
+
+        ConnectionParams(
+                String[] commandLine, FileDescriptorInfo[] filesToBeMapped, IBinder callback) {
+            mCommandLine = commandLine;
+            mFilesToBeMapped = filesToBeMapped;
+            mCallback = callback;
+        }
+    }
+
+    // Synchronization: While most internal flow occurs on the UI thread, the public API
+    // (specifically start and stop) may be called from any thread, hence all entry point methods
+    // into the class are synchronized on the lock to protect access to these members.
+    // TODO(jcivelli): crbug.com/714657 remove this lock.
+    private final Object mLock = new Object();
+
+    // This is set in start() and is used in onServiceConnected().
+    @GuardedBy("mLock")
+    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.
+    @GuardedBy("mLock")
+    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.
+    @GuardedBy("mLock")
+    private ConnectionCallback mConnectionCallback;
+
+    @GuardedBy("mLock")
+    private IChildProcessService mService;
+
+    // Set to true when the service connection callback runs. This differs from
+    // mServiceConnectComplete, which tracks that the connection completed successfully.
+    @GuardedBy("mLock")
+    private boolean mDidOnServiceConnected;
+
+    // Set to true when the service connected successfully.
+    @GuardedBy("mLock")
+    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.
+    @GuardedBy("mLock")
+    private boolean mServiceDisconnected;
+
+    // Process ID of the corresponding child process.
+    @GuardedBy("mLock")
+    private int mPid;
+
+    protected BaseChildProcessConnection(Context context, int number, boolean sandboxed,
+            DeathCallback deathCallback, String serviceClassName,
+            Bundle childProcessCommonParameters, ChildProcessCreationParams creationParams) {
         mContext = context;
         mServiceNumber = number;
-        mInSandbox = inSandbox;
+        mSandboxed = sandboxed;
         mDeathCallback = deathCallback;
         String packageName =
                 creationParams != null ? creationParams.getPackageName() : context.getPackageName();
         mServiceName = new ComponentName(packageName, serviceClassName + mServiceNumber);
         mChildProcessCommonParameters = childProcessCommonParameters;
-        mAlwaysInForeground = alwaysInForeground;
         mCreationParams = creationParams;
-        int initialFlags = Context.BIND_AUTO_CREATE;
-        if (mAlwaysInForeground) initialFlags |= Context.BIND_IMPORTANT;
-        int extraBindFlags = 0;
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && mCreationParams != null
-                && mCreationParams.getIsExternalService()
-                && isExportedService(inSandbox, mContext, mServiceName)) {
-            extraBindFlags = Context.BIND_EXTERNAL_SERVICE;
-        }
-        mInitialBinding = new ChildServiceConnection(initialFlags | extraBindFlags);
-        mStrongBinding = new ChildServiceConnection(
-                Context.BIND_AUTO_CREATE | Context.BIND_IMPORTANT | extraBindFlags);
-        mWaivedBinding = new ChildServiceConnection(
-                Context.BIND_AUTO_CREATE | Context.BIND_WAIVE_PRIORITY | extraBindFlags);
-        mModerateBinding = new ChildServiceConnection(Context.BIND_AUTO_CREATE | extraBindFlags);
     }
 
-    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;
+    public final Context getContext() {
+        return mContext;
     }
 
-    @Override
-    public int getServiceNumber() {
+    public final int getServiceNumber() {
         return mServiceNumber;
     }
 
-    @Override
-    public boolean isInSandbox() {
-        return mInSandbox;
+    public final boolean isSandboxed() {
+        return mSandboxed;
     }
 
-    @Override
-    public String getPackageName() {
+    public final String getPackageName() {
         return mCreationParams != null ? mCreationParams.getPackageName()
-                : mContext.getPackageName();
+                                       : mContext.getPackageName();
     }
 
-    @Override
-    public ChildProcessCreationParams getCreationParams() {
+    public final ChildProcessCreationParams getCreationParams() {
         return mCreationParams;
     }
 
-    @Override
-    public IChildProcessService getService() {
+    public final IChildProcessService getService() {
         synchronized (mLock) {
             return mService;
         }
     }
 
-    @Override
+    public final ComponentName getServiceName() {
+        return mServiceName;
+    }
+
+    /**
+     * @return the connection pid, or 0 if not yet connected
+     */
     public int getPid() {
         synchronized (mLock) {
             return mPid;
         }
     }
 
-    @Override
-    public void start(ChildProcessConnection.StartCallback startCallback) {
+    /**
+     * 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) {
         try {
-            TraceEvent.begin("ChildProcessConnectionImpl.start");
+            TraceEvent.begin("BaseChildProcessConnection.start");
             assert LauncherThread.runningOnLauncherThread();
             synchronized (mLock) {
-                assert mConnectionParams == null :
-                        "setupConnection() called before start() in ChildProcessConnectionImpl.";
+                assert mConnectionParams
+                        == null
+                        : "setupConnection() called before start() in BaseChildProcessConnection.";
 
                 mStartCallback = startCallback;
 
-                if (!mInitialBinding.bind()) {
+                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(ChildProcessConnectionImpl.this);
-                } else {
-                    mWaivedBinding.bind();
+                    mDeathCallback.onChildProcessDied(BaseChildProcessConnection.this);
                 }
             }
         } finally {
-            TraceEvent.end("ChildProcessConnectionImpl.start");
+            TraceEvent.end("BaseChildProcessConnection.start");
         }
     }
 
-    @Override
+    /**
+     * 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();
@@ -298,11 +331,11 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
             assert mConnectionParams == null;
             if (mServiceDisconnected) {
                 Log.w(TAG, "Tried to setup a connection that already disconnected.");
-                connectionCallback.onConnected(0);
+                connectionCallback.onConnected(null);
                 return;
             }
             try {
-                TraceEvent.begin("ChildProcessConnectionImpl.setupConnection");
+                TraceEvent.begin("BaseChildProcessConnection.setupConnection");
                 mConnectionCallback = connectionCallback;
                 mConnectionParams = new ConnectionParams(commandLine, filesToBeMapped, callback);
                 // Run the setup if the service is already connected. If not,
@@ -311,22 +344,19 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
                     doConnectionSetupLocked();
                 }
             } finally {
-                TraceEvent.end("ChildProcessConnectionImpl.setupConnection");
+                TraceEvent.end("BaseChildProcessConnection.setupConnection");
             }
         }
     }
 
-    @Override
+    /**
+     * Terminates the connection to IChildProcessService, closing all bindings. It is safe to call
+     * this multiple times.
+     */
     public void stop() {
         synchronized (mLock) {
-            mInitialBinding.unbind();
-            mStrongBinding.unbind();
-            mWaivedBinding.unbind();
-            mModerateBinding.unbind();
-            mStrongBindingCount = 0;
-            if (mService != null) {
-                mService = null;
-            }
+            unbind();
+            mService = null;
             mConnectionParams = null;
         }
     }
@@ -341,7 +371,7 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
             }
             try {
                 TraceEvent.begin(
-                        "ChildProcessConnectionImpl.ChildServiceConnection.onServiceConnected");
+                        "BaseChildProcessConnection.ChildServiceConnection.onServiceConnected");
                 mDidOnServiceConnected = true;
                 mService = IChildProcessService.Stub.asInterface(service);
 
@@ -381,7 +411,7 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
                 }
             } finally {
                 TraceEvent.end(
-                        "ChildProcessConnectionImpl.ChildServiceConnection.onServiceConnected");
+                        "BaseChildProcessConnection.ChildServiceConnection.onServiceConnected");
             }
         }
     }
@@ -394,16 +424,14 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
             if (mServiceDisconnected) {
                 return;
             }
-            // Stash the status of the oom bindings, since stop() will release all bindings.
-            mWasOomProtected = isCurrentlyOomProtected();
             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(ChildProcessConnectionImpl.this);
+            mDeathCallback.onChildProcessDied(BaseChildProcessConnection.this);
             // If we have a pending connection callback, we need to communicate the failure to
             // the caller.
             if (mConnectionCallback != null) {
-                mConnectionCallback.onConnected(0);
+                mConnectionCallback.onConnected(null);
             }
             mConnectionCallback = null;
         }
@@ -415,7 +443,7 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
             assert mPid != 0 : "Child service claims to be run by a process of pid=0.";
 
             if (mConnectionCallback != null) {
-                mConnectionCallback.onConnected(mPid);
+                mConnectionCallback.onConnected(this);
             }
             mConnectionCallback = null;
         }
@@ -426,9 +454,10 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
      * connection has been established (as signaled by onServiceConnected()). These two events can
      * happen in any order. Has to be called with mLock.
      */
+    @GuardedBy("mLock")
     private void doConnectionSetupLocked() {
         try {
-            TraceEvent.begin("ChildProcessConnectionImpl.doConnectionSetupLocked");
+            TraceEvent.begin("BaseChildProcessConnection.doConnectionSetupLocked");
             assert mServiceConnectComplete && mService != null;
             assert mConnectionParams != null;
 
@@ -460,129 +489,55 @@ public class ChildProcessConnectionImpl implements ChildProcessConnection {
             }
             mConnectionParams = null;
         } finally {
-            TraceEvent.end("ChildProcessConnectionImpl.doConnectionSetupLocked");
-        }
-    }
-
-    @Override
-    public boolean isInitialBindingBound() {
-        synchronized (mLock) {
-            return mInitialBinding.isBound();
-        }
-    }
-
-    @Override
-    public boolean isStrongBindingBound() {
-        synchronized (mLock) {
-            return mStrongBinding.isBound();
-        }
-    }
-
-    @Override
-    public void removeInitialBinding() {
-        synchronized (mLock) {
-            assert !mAlwaysInForeground;
-            mInitialBinding.unbind();
-        }
-    }
-
-    @Override
-    public boolean isOomProtectedOrWasWhenDied() {
-        synchronized (mLock) {
-            if (mServiceDisconnected) {
-                return mWasOomProtected;
-            } else {
-                return isCurrentlyOomProtected();
-            }
-        }
-    }
-
-    private boolean isCurrentlyOomProtected() {
-        synchronized (mLock) {
-            assert !mServiceDisconnected;
-            if (mAlwaysInForeground) return ChildProcessLauncher.isApplicationInForeground();
-            return mInitialBinding.isBound() || mStrongBinding.isBound();
+            TraceEvent.end("BaseChildProcessConnection.doConnectionSetupLocked");
         }
     }
 
-    @Override
-    public void dropOomBindings() {
-        synchronized (mLock) {
-            assert !mAlwaysInForeground;
-            mInitialBinding.unbind();
-
-            mStrongBindingCount = 0;
-            mStrongBinding.unbind();
+    /** Subclasses should implement this method to bind/unbind to the actual service. */
+    protected abstract boolean bind();
+    protected abstract void unbind();
 
-            mModerateBinding.unbind();
-        }
+    protected ChildServiceConnection createServiceConnection(int bindFlags) {
+        return new ChildServiceConnectionImpl(bindFlags);
     }
 
-    @Override
-    public void addStrongBinding() {
-        synchronized (mLock) {
-            if (mService == null) {
-                Log.w(TAG, "The connection is not bound for %d", mPid);
-                return;
-            }
-            if (mStrongBindingCount == 0) {
-                mStrongBinding.bind();
-            }
-            mStrongBindingCount++;
-        }
-    }
-
-    @Override
-    public void removeStrongBinding() {
-        synchronized (mLock) {
-            if (mService == null) {
-                Log.w(TAG, "The connection is not bound for %d", mPid);
-                return;
-            }
-            assert mStrongBindingCount > 0;
-            mStrongBindingCount--;
-            if (mStrongBindingCount == 0) {
-                mStrongBinding.unbind();
-            }
-        }
-    }
-
-    @Override
-    public boolean isModerateBindingBound() {
-        synchronized (mLock) {
-            return mModerateBinding.isBound();
-        }
+    protected boolean shouldBindAsExportedService() {
+        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.N && getCreationParams() != null
+                && getCreationParams().getIsExternalService()
+                && isExportedService(isSandboxed(), getContext(), getServiceName());
     }
 
-    @Override
-    public void addModerateBinding() {
-        synchronized (mLock) {
-            if (mService == null) {
-                Log.w(TAG, "The connection is not bound for %d", mPid);
-                return;
-            }
-            mModerateBinding.bind();
+    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();
         }
-    }
-
-    @Override
-    public void removeModerateBinding() {
-        synchronized (mLock) {
-            if (mService == null) {
-                Log.w(TAG, "The connection is not bound for %d", mPid);
-                return;
-            }
-            mModerateBinding.unbind();
+        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;
     }
 
     @VisibleForTesting
     public void crashServiceForTesting() throws RemoteException {
-        mService.crashIntentionallyForTesting();
+        synchronized (mLock) {
+            mService.crashIntentionallyForTesting();
+        }
     }
 
     @VisibleForTesting
     public boolean isConnected() {
-        return mService != null;
+        synchronized (mLock) {
+            return mService != null;
+        }
     }
 }