| /* |
| * Copyright 2020 The gRPC Authors |
| * |
| * 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 io.grpc.binder.internal; |
| |
| import android.os.Binder; |
| import android.os.Parcel; |
| import io.grpc.Internal; |
| import java.util.logging.Level; |
| import java.util.logging.Logger; |
| import javax.annotation.Nullable; |
| |
| /** |
| * An extension of {@link Binder} which delegates all transactions to an internal handler, and only |
| * supports one way transactions. |
| * |
| * <p>Since Binder objects can be anchored forever by a misbehaved remote process, any references |
| * they hold can lead to significant memory leaks. To prevent that, the {@link #detach} method |
| * clears the reference to the delegate handler, ensuring that only this simple class is leaked. |
| * Once detached, this binder returns false from any future transactions (and pings). |
| * |
| * <p>Since two-way transactions block the calling thread on a remote process, this class only |
| * supports one-way calls. |
| */ |
| @Internal |
| public final class LeakSafeOneWayBinder extends Binder { |
| |
| private static final Logger logger = Logger.getLogger(LeakSafeOneWayBinder.class.getName()); |
| |
| @Internal |
| public interface TransactionHandler { |
| boolean handleTransaction(int code, Parcel data); |
| } |
| |
| @Nullable private TransactionHandler handler; |
| |
| public LeakSafeOneWayBinder(TransactionHandler handler) { |
| this.handler = handler; |
| } |
| |
| public void detach() { |
| handler = null; |
| } |
| |
| @Override |
| protected boolean onTransact(int code, Parcel parcel, Parcel reply, int flags) { |
| TransactionHandler handler = this.handler; |
| if (handler != null) { |
| try { |
| return handler.handleTransaction(code, parcel); |
| } catch (RuntimeException re) { |
| logger.log(Level.WARNING, "failure sending transaction " + code, re); |
| return false; |
| } |
| } else { |
| return false; |
| } |
| } |
| |
| @Override |
| public boolean pingBinder() { |
| return handler != null; |
| } |
| } |