io.netty.channel.nio.AbstractNioByteChannel Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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:
*
* https://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.netty.channel.nio;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.Channel;
import io.netty.channel.ChannelConfig;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelMetadata;
import io.netty.channel.ChannelOutboundBuffer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.FileRegion;
import io.netty.channel.RecvByteBufAllocator;
import io.netty.channel.internal.ChannelUtils;
import io.netty.channel.socket.ChannelInputShutdownEvent;
import io.netty.channel.socket.ChannelInputShutdownReadComplete;
import io.netty.channel.socket.SocketChannelConfig;
import io.netty.util.internal.StringUtil;
import java.io.IOException;
import java.nio.channels.SelectableChannel;
import java.nio.channels.SelectionKey;
import static io.netty.channel.internal.ChannelUtils.WRITE_STATUS_SNDBUF_FULL;
/**
* {@link AbstractNioChannel} base class for {@link Channel}s that operate on bytes.
*/
public abstract class AbstractNioByteChannel extends AbstractNioChannel {
private static final ChannelMetadata METADATA = new ChannelMetadata(false, 16);
private static final String EXPECTED_TYPES =
" (expected: " + StringUtil.simpleClassName(ByteBuf.class) + ", " +
StringUtil.simpleClassName(FileRegion.class) + ')';
private final Runnable flushTask = new Runnable() {
@Override
public void run() {
// Calling flush0 directly to ensure we not try to flush messages that were added via write(...) in the
// meantime.
((AbstractNioUnsafe) unsafe()).flush0();
}
};
private boolean inputClosedSeenErrorOnRead;
/**
* Create a new instance
*
* @param parent the parent {@link Channel} by which this instance was created. May be {@code null}
* @param ch the underlying {@link SelectableChannel} on which it operates
*/
protected AbstractNioByteChannel(Channel parent, SelectableChannel ch) {
super(parent, ch, SelectionKey.OP_READ);
}
/**
* Shutdown the input side of the channel.
*/
protected abstract ChannelFuture shutdownInput();
protected boolean isInputShutdown0() {
return false;
}
@Override
protected AbstractNioUnsafe newUnsafe() {
return new NioByteUnsafe();
}
@Override
public ChannelMetadata metadata() {
return METADATA;
}
final boolean shouldBreakReadReady(ChannelConfig config) {
return isInputShutdown0() && (inputClosedSeenErrorOnRead || !isAllowHalfClosure(config));
}
private static boolean isAllowHalfClosure(ChannelConfig config) {
return config instanceof SocketChannelConfig &&
((SocketChannelConfig) config).isAllowHalfClosure();
}
protected class NioByteUnsafe extends AbstractNioUnsafe {
private void closeOnRead(ChannelPipeline pipeline) {
if (!isInputShutdown0()) {
if (isAllowHalfClosure(config())) {
shutdownInput();
pipeline.fireUserEventTriggered(ChannelInputShutdownEvent.INSTANCE);
} else {
close(voidPromise());
}
} else if (!inputClosedSeenErrorOnRead) {
inputClosedSeenErrorOnRead = true;
pipeline.fireUserEventTriggered(ChannelInputShutdownReadComplete.INSTANCE);
}
}
private void handleReadException(ChannelPipeline pipeline, ByteBuf byteBuf, Throwable cause, boolean close,
RecvByteBufAllocator.Handle allocHandle) {
if (byteBuf != null) {
if (byteBuf.isReadable()) {
readPending = false;
pipeline.fireChannelRead(byteBuf);
} else {
byteBuf.release();
}
}
allocHandle.readComplete();
pipeline.fireChannelReadComplete();
pipeline.fireExceptionCaught(cause);
// If oom will close the read event, release connection.
// See https://github.com/netty/netty/issues/10434
if (close || cause instanceof OutOfMemoryError || cause instanceof IOException) {
closeOnRead(pipeline);
}
}
@Override
public final void read() {
final ChannelConfig config = config();
if (shouldBreakReadReady(config)) {
clearReadPending();
return;
}
final ChannelPipeline pipeline = pipeline();
final ByteBufAllocator allocator = config.getAllocator();
final RecvByteBufAllocator.Handle allocHandle = recvBufAllocHandle();
allocHandle.reset(config);
ByteBuf byteBuf = null;
boolean close = false;
try {
do {
byteBuf = allocHandle.allocate(allocator);
allocHandle.lastBytesRead(doReadBytes(byteBuf));
if (allocHandle.lastBytesRead() <= 0) {
// nothing was read. release the buffer.
byteBuf.release();
byteBuf = null;
close = allocHandle.lastBytesRead() < 0;
if (close) {
// There is nothing left to read as we received an EOF.
readPending = false;
}
break;
}
allocHandle.incMessagesRead(1);
readPending = false;
pipeline.fireChannelRead(byteBuf);
byteBuf = null;
} while (allocHandle.continueReading());
allocHandle.readComplete();
pipeline.fireChannelReadComplete();
if (close) {
closeOnRead(pipeline);
}
} catch (Throwable t) {
handleReadException(pipeline, byteBuf, t, close, allocHandle);
} finally {
// Check if there is a readPending which was not processed yet.
// This could be for two reasons:
// * The user called Channel.read() or ChannelHandlerContext.read() in channelRead(...) method
// * The user called Channel.read() or ChannelHandlerContext.read() in channelReadComplete(...) method
//
// See https://github.com/netty/netty/issues/2254
if (!readPending && !config.isAutoRead()) {
removeReadOp();
}
}
}
}
/**
* Write objects to the OS.
* @param in the collection which contains objects to write.
* @return The value that should be decremented from the write quantum which starts at
* {@link ChannelConfig#getWriteSpinCount()}. The typical use cases are as follows:
*
* - 0 - if no write was attempted. This is appropriate if an empty {@link ByteBuf} (or other empty content)
* is encountered
* - 1 - if a single call to write data was made to the OS
* - {@link ChannelUtils#WRITE_STATUS_SNDBUF_FULL} - if an attempt to write data was made to the OS, but no
* data was accepted
*
* @throws Exception if an I/O exception occurs during write.
*/
protected final int doWrite0(ChannelOutboundBuffer in) throws Exception {
Object msg = in.current();
if (msg == null) {
// Directly return here so incompleteWrite(...) is not called.
return 0;
}
return doWriteInternal(in, in.current());
}
private int doWriteInternal(ChannelOutboundBuffer in, Object msg) throws Exception {
if (msg instanceof ByteBuf) {
ByteBuf buf = (ByteBuf) msg;
if (!buf.isReadable()) {
in.remove();
return 0;
}
final int localFlushedAmount = doWriteBytes(buf);
if (localFlushedAmount > 0) {
in.progress(localFlushedAmount);
if (!buf.isReadable()) {
in.remove();
}
return 1;
}
} else if (msg instanceof FileRegion) {
FileRegion region = (FileRegion) msg;
if (region.transferred() >= region.count()) {
in.remove();
return 0;
}
long localFlushedAmount = doWriteFileRegion(region);
if (localFlushedAmount > 0) {
in.progress(localFlushedAmount);
if (region.transferred() >= region.count()) {
in.remove();
}
return 1;
}
} else {
// Should not reach here.
throw new Error();
}
return WRITE_STATUS_SNDBUF_FULL;
}
@Override
protected void doWrite(ChannelOutboundBuffer in) throws Exception {
int writeSpinCount = config().getWriteSpinCount();
do {
Object msg = in.current();
if (msg == null) {
// Wrote all messages.
clearOpWrite();
// Directly return here so incompleteWrite(...) is not called.
return;
}
writeSpinCount -= doWriteInternal(in, msg);
} while (writeSpinCount > 0);
incompleteWrite(writeSpinCount < 0);
}
@Override
protected final Object filterOutboundMessage(Object msg) {
if (msg instanceof ByteBuf) {
ByteBuf buf = (ByteBuf) msg;
if (buf.isDirect()) {
return msg;
}
return newDirectBuffer(buf);
}
if (msg instanceof FileRegion) {
return msg;
}
throw new UnsupportedOperationException(
"unsupported message type: " + StringUtil.simpleClassName(msg) + EXPECTED_TYPES);
}
protected final void incompleteWrite(boolean setOpWrite) {
// Did not write completely.
if (setOpWrite) {
setOpWrite();
} else {
// It is possible that we have set the write OP, woken up by NIO because the socket is writable, and then
// use our write quantum. In this case we no longer want to set the write OP because the socket is still
// writable (as far as we know). We will find out next time we attempt to write if the socket is writable
// and set the write OP if necessary.
clearOpWrite();
// Schedule flush again later so other tasks can be picked up in the meantime
eventLoop().execute(flushTask);
}
}
/**
* Write a {@link FileRegion}
*
* @param region the {@link FileRegion} from which the bytes should be written
* @return amount the amount of written bytes
*/
protected abstract long doWriteFileRegion(FileRegion region) throws Exception;
/**
* Read bytes into the given {@link ByteBuf} and return the amount.
*/
protected abstract int doReadBytes(ByteBuf buf) throws Exception;
/**
* Write bytes form the given {@link ByteBuf} to the underlying {@link java.nio.channels.Channel}.
* @param buf the {@link ByteBuf} from which the bytes should be written
* @return amount the amount of written bytes
*/
protected abstract int doWriteBytes(ByteBuf buf) throws Exception;
protected final void setOpWrite() {
final SelectionKey key = selectionKey();
// Check first if the key is still valid as it may be canceled as part of the deregistration
// from the EventLoop
// See https://github.com/netty/netty/issues/2104
if (!key.isValid()) {
return;
}
final int interestOps = key.interestOps();
if ((interestOps & SelectionKey.OP_WRITE) == 0) {
key.interestOps(interestOps | SelectionKey.OP_WRITE);
}
}
protected final void clearOpWrite() {
final SelectionKey key = selectionKey();
// Check first if the key is still valid as it may be canceled as part of the deregistration
// from the EventLoop
// See https://github.com/netty/netty/issues/2104
if (!key.isValid()) {
return;
}
final int interestOps = key.interestOps();
if ((interestOps & SelectionKey.OP_WRITE) != 0) {
key.interestOps(interestOps & ~SelectionKey.OP_WRITE);
}
}
}