Merge "Fix ConcurrentModificationException in AcceptOnceConsumer" into tm-qpr-dev (8642c7f7) · Commits · e / os / android_frameworks_base

libs/WindowManager/Jetpack/src/androidx/window/util/AcceptOnceConsumer.java

+18 −3

Original line number	Diff line number	Diff line
		@@ -27,9 +27,10 @@ import java.util.function.Consumer;
		*/
		public class AcceptOnceConsumer<T> implements Consumer<T> {
		private final Consumer<T> mCallback;
		private final DataProducer<T> mProducer;
		private final AcceptOnceProducerCallback<T> mProducer;

		public AcceptOnceConsumer(@NonNull DataProducer<T> producer, @NonNull Consumer<T> callback) {
		public AcceptOnceConsumer(@NonNull AcceptOnceProducerCallback<T> producer,
		@NonNull Consumer<T> callback) {
		mProducer = producer;
		mCallback = callback;
		}
		@@ -37,6 +38,20 @@ public class AcceptOnceConsumer<T> implements Consumer<T> {
		@Override
		public void accept(@NonNull T t) {
		mCallback.accept(t);
		mProducer.removeDataChangedCallback(this);
		mProducer.onConsumerReadyToBeRemoved(this);
		}

		/**
		* Interface to allow the {@link AcceptOnceConsumer} to notify the client that created it,
		* when it is ready to be removed. This allows the client to remove the consumer object
		* when it deems it is safe to do so.
		* @param <T> The type of data this callback accepts through {@link #onConsumerReadyToBeRemoved}
		*/
		public interface AcceptOnceProducerCallback<T> {

		/**
		* Notifies that the given {@code callback} is ready to be removed
		*/
		void onConsumerReadyToBeRemoved(Consumer<T> callback);
		}
		}

libs/WindowManager/Jetpack/src/androidx/window/util/BaseDataProducer.java

+25 −1

Original line number	Diff line number	Diff line
		@@ -19,6 +19,7 @@ package androidx.window.util;
		import androidx.annotation.GuardedBy;
		import androidx.annotation.NonNull;

		import java.util.HashSet;
		import java.util.LinkedHashSet;
		import java.util.Optional;
		import java.util.Set;
		@@ -31,11 +32,14 @@ import java.util.function.Consumer;
		*
		* @param <T> The type of data this producer returns through {@link DataProducer#getData}.
		*/
		public abstract class BaseDataProducer<T> implements DataProducer<T> {
		public abstract class BaseDataProducer<T> implements DataProducer<T>,
		AcceptOnceConsumer.AcceptOnceProducerCallback<T> {

		private final Object mLock = new Object();
		@GuardedBy("mLock")
		private final Set<Consumer<T>> mCallbacks = new LinkedHashSet<>();
		@GuardedBy("mLock")
		private final Set<Consumer<T>> mCallbacksToRemove = new HashSet<>();

		/**
		* Adds a callback to the set of callbacks listening for data. Data is delivered through
		@@ -85,6 +89,26 @@ public abstract class BaseDataProducer<T> implements DataProducer<T> {
		for (Consumer<T> callback : mCallbacks) {
		callback.accept(value);
		}
		removeFinishedCallbacksLocked();
		}
		}

		/**
		* Removes any callbacks that notified us through {@link #onConsumerReadyToBeRemoved(Consumer)}
		* that they are ready to be removed.
		*/
		@GuardedBy("mLock")
		private void removeFinishedCallbacksLocked() {
		for (Consumer<T> callback: mCallbacksToRemove) {
		mCallbacks.remove(callback);
		}
		mCallbacksToRemove.clear();
		}

		@Override
		public void onConsumerReadyToBeRemoved(Consumer<T> callback) {
		synchronized (mLock) {
		mCallbacksToRemove.add(callback);
		}
		}
		}
		No newline at end of file