| /* |
| * Copyright (C) 2014 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.telecom; |
| |
| import android.content.ComponentName; |
| import android.content.Context; |
| import android.content.Intent; |
| import android.content.ServiceConnection; |
| import android.os.IBinder; |
| import android.os.IInterface; |
| import android.text.TextUtils; |
| import android.util.ArraySet; |
| |
| import com.android.internal.util.Preconditions; |
| |
| import java.util.Collections; |
| import java.util.Set; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| /** |
| * Abstract class to perform the work of binding and unbinding to the specified service interface. |
| * Subclasses supply the service intent and component name and this class will invoke protected |
| * methods when the class is bound, unbound, or upon failure. |
| */ |
| abstract class ServiceBinder<ServiceInterface extends IInterface> { |
| |
| /** |
| * Callback to notify after a binding succeeds or fails. |
| */ |
| interface BindCallback { |
| void onSuccess(); |
| void onFailure(); |
| } |
| |
| /** |
| * Listener for bind events on ServiceBinder. |
| */ |
| interface Listener<ServiceBinderClass extends ServiceBinder<?>> { |
| void onUnbind(ServiceBinderClass serviceBinder); |
| } |
| |
| /** |
| * Helper class to perform on-demand binding. |
| */ |
| final class Binder { |
| /** |
| * Performs an asynchronous bind to the service (only if not already bound) and executes the |
| * specified callback. |
| * |
| * @param callback The callback to notify of the binding's success or failure. |
| */ |
| void bind(BindCallback callback) { |
| ThreadUtil.checkOnMainThread(); |
| Log.d(ServiceBinder.this, "bind()"); |
| |
| // Reset any abort request if we're asked to bind again. |
| clearAbort(); |
| |
| if (!mCallbacks.isEmpty()) { |
| // Binding already in progress, append to the list of callbacks and bail out. |
| mCallbacks.add(callback); |
| return; |
| } |
| |
| mCallbacks.add(callback); |
| if (mServiceConnection == null) { |
| Intent serviceIntent = new Intent(mServiceAction).setComponent(mComponentName); |
| ServiceConnection connection = new ServiceBinderConnection(); |
| |
| Log.d(ServiceBinder.this, "Binding to service with intent: %s", serviceIntent); |
| if (!mContext.bindService(serviceIntent, connection, Context.BIND_AUTO_CREATE)) { |
| handleFailedConnection(); |
| return; |
| } |
| } else { |
| Log.d(ServiceBinder.this, "Service is already bound."); |
| Preconditions.checkNotNull(mBinder); |
| handleSuccessfulConnection(); |
| } |
| } |
| } |
| |
| private final class ServiceBinderConnection implements ServiceConnection { |
| @Override |
| public void onServiceConnected(ComponentName componentName, IBinder binder) { |
| ThreadUtil.checkOnMainThread(); |
| Log.i(this, "Service bound %s", componentName); |
| |
| // Unbind request was queued so unbind immediately. |
| if (mIsBindingAborted) { |
| clearAbort(); |
| logServiceDisconnected("onServiceConnected"); |
| mContext.unbindService(this); |
| handleFailedConnection(); |
| return; |
| } |
| |
| mServiceConnection = this; |
| setBinder(binder); |
| handleSuccessfulConnection(); |
| } |
| |
| @Override |
| public void onServiceDisconnected(ComponentName componentName) { |
| logServiceDisconnected("onServiceDisconnected"); |
| |
| mServiceConnection = null; |
| clearAbort(); |
| |
| handleServiceDisconnected(); |
| } |
| } |
| |
| /** The application context. */ |
| private final Context mContext; |
| |
| /** The intent action to use when binding through {@link Context#bindService}. */ |
| private final String mServiceAction; |
| |
| /** The component name of the service to bind to. */ |
| private final ComponentName mComponentName; |
| |
| /** The set of callbacks waiting for notification of the binding's success or failure. */ |
| private final Set<BindCallback> mCallbacks = new ArraySet<>(); |
| |
| /** Used to bind and unbind from the service. */ |
| private ServiceConnection mServiceConnection; |
| |
| /** The binder provided by {@link ServiceConnection#onServiceConnected} */ |
| private IBinder mBinder; |
| |
| private int mAssociatedCallCount = 0; |
| |
| /** |
| * Indicates that an unbind request was made when the service was not yet bound. If the service |
| * successfully connects when this is true, it should be unbound immediately. |
| */ |
| private boolean mIsBindingAborted; |
| |
| /** |
| * Set of currently registered listeners. |
| * ConcurrentHashMap constructor params: 8 is initial table size, 0.9f is |
| * load factor before resizing, 1 means we only expect a single thread to |
| * access the map so make only a single shard |
| */ |
| private final Set<Listener> mListeners = Collections.newSetFromMap( |
| new ConcurrentHashMap<Listener, Boolean>(8, 0.9f, 1)); |
| |
| /** |
| * Persists the specified parameters and initializes the new instance. |
| * |
| * @param serviceAction The intent-action used with {@link Context#bindService}. |
| * @param componentName The component name of the service with which to bind. |
| * @param context The context. |
| */ |
| protected ServiceBinder(String serviceAction, ComponentName componentName, Context context) { |
| Preconditions.checkState(!TextUtils.isEmpty(serviceAction)); |
| Preconditions.checkNotNull(componentName); |
| |
| mContext = context; |
| mServiceAction = serviceAction; |
| mComponentName = componentName; |
| } |
| |
| final void incrementAssociatedCallCount() { |
| mAssociatedCallCount++; |
| Log.v(this, "Call count increment %d, %s", mAssociatedCallCount, |
| mComponentName.flattenToShortString()); |
| } |
| |
| final void decrementAssociatedCallCount() { |
| if (mAssociatedCallCount > 0) { |
| mAssociatedCallCount--; |
| Log.v(this, "Call count decrement %d, %s", mAssociatedCallCount, |
| mComponentName.flattenToShortString()); |
| |
| if (mAssociatedCallCount == 0) { |
| unbind(); |
| } |
| } else { |
| Log.wtf(this, "%s: ignoring a request to decrement mAssociatedCallCount below zero", |
| mComponentName.getClassName()); |
| } |
| } |
| |
| final int getAssociatedCallCount() { |
| return mAssociatedCallCount; |
| } |
| |
| /** |
| * Unbinds from the service if already bound, no-op otherwise. |
| */ |
| final void unbind() { |
| ThreadUtil.checkOnMainThread(); |
| |
| if (mServiceConnection == null) { |
| // We're not yet bound, so queue up an abort request. |
| mIsBindingAborted = true; |
| } else { |
| logServiceDisconnected("unbind"); |
| mContext.unbindService(mServiceConnection); |
| mServiceConnection = null; |
| setBinder(null); |
| } |
| } |
| |
| final ComponentName getComponentName() { |
| return mComponentName; |
| } |
| |
| final boolean isServiceValid(String actionName) { |
| if (mBinder == null) { |
| Log.w(this, "%s invoked while service is unbound", actionName); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| final void addListener(Listener listener) { |
| mListeners.add(listener); |
| } |
| |
| final void removeListener(Listener listener) { |
| if (listener != null) { |
| mListeners.remove(listener); |
| } |
| } |
| |
| /** |
| * Logs a standard message upon service disconnection. This method exists because there is no |
| * single method called whenever the service unbinds and we want to log the same string in all |
| * instances where that occurs. (Context.unbindService() does not cause onServiceDisconnected |
| * to execute). |
| * |
| * @param sourceTag Tag to disambiguate |
| */ |
| private void logServiceDisconnected(String sourceTag) { |
| Log.i(this, "Service unbound %s, from %s.", mComponentName, sourceTag); |
| } |
| |
| /** |
| * Notifies all the outstanding callbacks that the service is successfully bound. The list of |
| * outstanding callbacks is cleared afterwards. |
| */ |
| private void handleSuccessfulConnection() { |
| for (BindCallback callback : mCallbacks) { |
| callback.onSuccess(); |
| } |
| mCallbacks.clear(); |
| } |
| |
| /** |
| * Notifies all the outstanding callbacks that the service failed to bind. The list of |
| * outstanding callbacks is cleared afterwards. |
| */ |
| private void handleFailedConnection() { |
| for (BindCallback callback : mCallbacks) { |
| callback.onFailure(); |
| } |
| mCallbacks.clear(); |
| } |
| |
| /** |
| * Handles a service disconnection. |
| */ |
| private void handleServiceDisconnected() { |
| setBinder(null); |
| } |
| |
| private void clearAbort() { |
| mIsBindingAborted = false; |
| } |
| |
| /** |
| * Sets the (private) binder and updates the child class. |
| * |
| * @param binder The new binder value. |
| */ |
| private void setBinder(IBinder binder) { |
| if (mBinder != binder) { |
| mBinder = binder; |
| |
| setServiceInterface(binder); |
| |
| if (binder == null) { |
| for (Listener l : mListeners) { |
| l.onUnbind(this); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Sets the service interface after the service is bound or unbound. |
| * |
| * @param binder The actual bound service implementation. |
| */ |
| protected abstract void setServiceInterface(IBinder binder); |
| } |