| /* |
| * 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.cassandra.net; |
| |
| import java.nio.channels.FileChannel; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| import io.netty.channel.DefaultFileRegion; |
| import org.apache.cassandra.utils.concurrent.Ref; |
| import org.apache.cassandra.utils.concurrent.RefCounted; |
| |
| /** |
| * Netty's DefaultFileRegion closes the underlying FileChannel as soon as |
| * the refCnt() for the region drops to zero, this is an implementation of |
| * the DefaultFileRegion that doesn't close the FileChannel. |
| * |
| * See {@link AsyncChannelOutputPlus} for its usage. |
| */ |
| public class SharedDefaultFileRegion extends DefaultFileRegion |
| { |
| public static class SharedFileChannel |
| { |
| // we don't call .ref() on this, because it would generate a lot of PhantomReferences and GC overhead, |
| // but we use it to ensure we can spot memory leaks |
| final Ref<FileChannel> ref; |
| final AtomicInteger refCount = new AtomicInteger(1); |
| |
| SharedFileChannel(FileChannel fileChannel) |
| { |
| this.ref = new Ref<>(fileChannel, new RefCounted.Tidy() |
| { |
| public void tidy() throws Exception |
| { |
| // don't mind invoking this on eventLoop, as only used with sendFile which is also blocking |
| // so must use streaming eventLoop |
| fileChannel.close(); |
| } |
| |
| public String name() |
| { |
| return "SharedFileChannel[" + fileChannel.toString() + ']'; |
| } |
| }); |
| } |
| |
| public void release() |
| { |
| if (0 == refCount.decrementAndGet()) |
| ref.release(); |
| } |
| } |
| |
| private final SharedFileChannel shared; |
| private boolean deallocated = false; |
| |
| SharedDefaultFileRegion(SharedFileChannel shared, long position, long count) |
| { |
| super(shared.ref.get(), position, count); |
| this.shared = shared; |
| if (1 >= this.shared.refCount.incrementAndGet()) |
| throw new IllegalStateException(); |
| } |
| |
| @Override |
| protected void deallocate() |
| { |
| if (deallocated) |
| return; |
| deallocated = true; |
| shared.release(); |
| } |
| |
| public static SharedFileChannel share(FileChannel fileChannel) |
| { |
| return new SharedFileChannel(fileChannel); |
| } |
| } |