RemoteCallback.java
/*
* Copyright 2020 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 androidx.work.multiprocess;
import android.os.IBinder;
import android.os.RemoteException;
import androidx.annotation.NonNull;
import androidx.annotation.RestrictTo;
import androidx.work.impl.utils.futures.SettableFuture;
import com.google.common.util.concurrent.ListenableFuture;
/**
* Manages callbacks from {@link IWorkManagerImpl}.
*
* @hide
*/
@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
public class RemoteCallback extends IWorkManagerImplCallback.Stub {
private final SettableFuture<byte[]> mFuture;
// The binder represents scope of the request
private IBinder mBinder;
private final IBinder.DeathRecipient mRecipient;
@NonNull
public ListenableFuture<byte[]> getFuture() {
return mFuture;
}
public RemoteCallback() {
mBinder = null;
mFuture = SettableFuture.create();
mRecipient = new DeathRecipient(this);
}
/**
* Sets the {@link IBinder} which represents the scope / lifetime for this callback.
*
* @param binder The instance of {@link IBinder}
*/
public void setBinder(@NonNull IBinder binder) {
mBinder = binder;
try {
mBinder.linkToDeath(mRecipient, 0);
} catch (RemoteException exception) {
onFailure(exception);
}
}
@Override
public void onSuccess(@NonNull byte[] result) throws RemoteException {
mFuture.set(result);
unlinkToDeath();
}
@Override
public void onFailure(@NonNull String error) {
onFailure(new RuntimeException(error));
}
private void onFailure(@NonNull Throwable throwable) {
mFuture.setException(throwable);
unlinkToDeath();
}
private void unlinkToDeath() {
if (mBinder != null) {
mBinder.unlinkToDeath(mRecipient, 0);
}
}
/**
* The {@link DeathRecipient} which helps track the lifetime of the {@link IBinder} that the
* callback is associated to.
*/
public static class DeathRecipient implements IBinder.DeathRecipient {
private final RemoteCallback mCallback;
public DeathRecipient(@NonNull RemoteCallback callback) {
mCallback = callback;
}
@Override
public void binderDied() {
mCallback.onFailure("Binder died");
}
}
}