zhijiangW commented on a change in pull request #11687: URL: https://github.com/apache/flink/pull/11687#discussion_r419487035
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/consumer/BufferManager.java ########## @@ -0,0 +1,356 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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 org.apache.flink.runtime.io.network.partition.consumer; + +import org.apache.flink.annotation.VisibleForTesting; +import org.apache.flink.core.memory.MemorySegment; +import org.apache.flink.core.memory.MemorySegmentProvider; +import org.apache.flink.runtime.io.network.buffer.Buffer; +import org.apache.flink.runtime.io.network.buffer.BufferListener; +import org.apache.flink.runtime.io.network.buffer.BufferPool; +import org.apache.flink.runtime.io.network.buffer.BufferRecycler; +import org.apache.flink.runtime.io.network.buffer.NetworkBuffer; +import org.apache.flink.util.ExceptionUtils; + +import javax.annotation.Nullable; +import javax.annotation.concurrent.GuardedBy; + +import java.io.IOException; +import java.util.ArrayDeque; +import java.util.ArrayList; +import java.util.Collection; +import java.util.Collections; +import java.util.List; + +import static org.apache.flink.util.Preconditions.checkArgument; +import static org.apache.flink.util.Preconditions.checkNotNull; +import static org.apache.flink.util.Preconditions.checkState; + +/** + * The general buffer manager used by {@link InputChannel} to request/recycle + * exclusive or floating buffers. + */ +public class BufferManager implements BufferListener, BufferRecycler { + + /** The available buffer queue wraps both exclusive and requested floating buffers. */ + private final AvailableBufferQueue bufferQueue = new AvailableBufferQueue(); + + /** The buffer provider for requesting exclusive buffers. */ + private final MemorySegmentProvider globalPool; + + /** The input channel to own this buffer manager. */ + private final InputChannel inputChannel; + + /** The tag indicates whether it is waiting for additional floating buffers from the buffer pool. */ + @GuardedBy("bufferQueue") + private boolean isWaitingForFloatingBuffers; + + /** The total number of required buffers for the respective input channel. */ + @GuardedBy("bufferQueue") + private int numRequiredBuffers; + + public BufferManager( + MemorySegmentProvider globalPool, + InputChannel inputChannel, Review comment: yeah, I also noticed this cycle dependency issue while implementation. And I also tried to cut it if easy to go. But actually I found it needs pay more efforts, because there are many interactions among `InputChannel` and `BufferManager`. 1. `BufferManager` relies on `BufferPool`, then while `SingleInputGate#setup`, it needs to register the respective `BufferPool` for every `InputChannel#BufferManager`. This is the main concern to bypass this issue at current implementation. 2. We also need to maintain the separate `isReleased` variable inside `BufferManager` to not rely on `InputChannel#isReleased`. 3. We might need another separate interface which would be implemented by `InputChannel`, then we can decouple another two depending methods `InputChannel#onError` and `InputChannel#notifyBufferAvailable`. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
