AbstractEpollStreamChannel.java
/*
* Copyright 2015 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.epoll;
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.ChannelFutureListener;
import io.netty.channel.ChannelMetadata;
import io.netty.channel.ChannelOutboundBuffer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelPromise;
import io.netty.channel.DefaultFileRegion;
import io.netty.channel.EventLoop;
import io.netty.channel.FileRegion;
import io.netty.channel.RecvByteBufAllocator;
import io.netty.channel.internal.ChannelUtils;
import io.netty.channel.socket.DuplexChannel;
import io.netty.channel.unix.FileDescriptor;
import io.netty.channel.unix.IovArray;
import io.netty.channel.unix.SocketWritableByteChannel;
import io.netty.channel.unix.UnixChannelUtil;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.StringUtil;
import io.netty.util.internal.UnstableApi;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.io.IOException;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.WritableByteChannel;
import java.util.Queue;
import java.util.concurrent.Executor;
import static io.netty.channel.internal.ChannelUtils.MAX_BYTES_PER_GATHERING_WRITE_ATTEMPTED_LOW_THRESHOLD;
import static io.netty.channel.internal.ChannelUtils.WRITE_STATUS_SNDBUF_FULL;
import static io.netty.channel.unix.FileDescriptor.pipe;
import static io.netty.util.internal.ObjectUtil.checkNotNull;
import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
public abstract class AbstractEpollStreamChannel extends AbstractEpollChannel implements DuplexChannel {
private static final ChannelMetadata METADATA = new ChannelMetadata(false, 16);
private static final String EXPECTED_TYPES =
" (expected: " + StringUtil.simpleClassName(ByteBuf.class) + ", " +
StringUtil.simpleClassName(DefaultFileRegion.class) + ')';
private static final InternalLogger logger = InternalLoggerFactory.getInstance(AbstractEpollStreamChannel.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.
((AbstractEpollUnsafe) unsafe()).flush0();
}
};
// Lazy init these if we need to splice(...)
private volatile Queue<SpliceInTask> spliceQueue;
private FileDescriptor pipeIn;
private FileDescriptor pipeOut;
private WritableByteChannel byteChannel;
protected AbstractEpollStreamChannel(Channel parent, int fd) {
this(parent, new LinuxSocket(fd));
}
protected AbstractEpollStreamChannel(int fd) {
this(new LinuxSocket(fd));
}
AbstractEpollStreamChannel(LinuxSocket fd) {
this(fd, isSoErrorZero(fd));
}
AbstractEpollStreamChannel(Channel parent, LinuxSocket fd) {
super(parent, fd, true);
// Add EPOLLRDHUP so we are notified once the remote peer close the connection.
flags |= Native.EPOLLRDHUP;
}
protected AbstractEpollStreamChannel(Channel parent, LinuxSocket fd, SocketAddress remote) {
super(parent, fd, remote);
// Add EPOLLRDHUP so we are notified once the remote peer close the connection.
flags |= Native.EPOLLRDHUP;
}
protected AbstractEpollStreamChannel(LinuxSocket fd, boolean active) {
super(null, fd, active);
// Add EPOLLRDHUP so we are notified once the remote peer close the connection.
flags |= Native.EPOLLRDHUP;
}
@Override
protected AbstractEpollUnsafe newUnsafe() {
return new EpollStreamUnsafe();
}
@Override
public ChannelMetadata metadata() {
return METADATA;
}
/**
* Splice from this {@link AbstractEpollStreamChannel} to another {@link AbstractEpollStreamChannel}.
* The {@code len} is the number of bytes to splice. If using {@link Integer#MAX_VALUE} it will
* splice until the {@link ChannelFuture} was canceled or it was failed.
*
* Please note:
* <ul>
* <li>both channels need to be registered to the same {@link EventLoop}, otherwise an
* {@link IllegalArgumentException} is thrown. </li>
* <li>{@link EpollChannelConfig#getEpollMode()} must be {@link EpollMode#LEVEL_TRIGGERED} for this and the
* target {@link AbstractEpollStreamChannel}</li>
* </ul>
*
*/
public final ChannelFuture spliceTo(final AbstractEpollStreamChannel ch, final int len) {
return spliceTo(ch, len, newPromise());
}
/**
* Splice from this {@link AbstractEpollStreamChannel} to another {@link AbstractEpollStreamChannel}.
* The {@code len} is the number of bytes to splice. If using {@link Integer#MAX_VALUE} it will
* splice until the {@link ChannelFuture} was canceled or it was failed.
*
* Please note:
* <ul>
* <li>both channels need to be registered to the same {@link EventLoop}, otherwise an
* {@link IllegalArgumentException} is thrown. </li>
* <li>{@link EpollChannelConfig#getEpollMode()} must be {@link EpollMode#LEVEL_TRIGGERED} for this and the
* target {@link AbstractEpollStreamChannel}</li>
* </ul>
*
*/
public final ChannelFuture spliceTo(final AbstractEpollStreamChannel ch, final int len,
final ChannelPromise promise) {
if (ch.eventLoop() != eventLoop()) {
throw new IllegalArgumentException("EventLoops are not the same.");
}
checkPositiveOrZero(len, "len");
if (ch.config().getEpollMode() != EpollMode.LEVEL_TRIGGERED
|| config().getEpollMode() != EpollMode.LEVEL_TRIGGERED) {
throw new IllegalStateException("spliceTo() supported only when using " + EpollMode.LEVEL_TRIGGERED);
}
checkNotNull(promise, "promise");
if (!isOpen()) {
promise.tryFailure(new ClosedChannelException());
} else {
addToSpliceQueue(new SpliceInChannelTask(ch, len, promise));
failSpliceIfClosed(promise);
}
return promise;
}
/**
* Splice from this {@link AbstractEpollStreamChannel} to another {@link FileDescriptor}.
* The {@code offset} is the offset for the {@link FileDescriptor} and {@code len} is the
* number of bytes to splice. If using {@link Integer#MAX_VALUE} it will splice until the
* {@link ChannelFuture} was canceled or it was failed.
*
* Please note:
* <ul>
* <li>{@link EpollChannelConfig#getEpollMode()} must be {@link EpollMode#LEVEL_TRIGGERED} for this
* {@link AbstractEpollStreamChannel}</li>
* <li>the {@link FileDescriptor} will not be closed after the {@link ChannelFuture} is notified</li>
* <li>this channel must be registered to an event loop or {@link IllegalStateException} will be thrown.</li>
* </ul>
*/
public final ChannelFuture spliceTo(final FileDescriptor ch, final int offset, final int len) {
return spliceTo(ch, offset, len, newPromise());
}
/**
* Splice from this {@link AbstractEpollStreamChannel} to another {@link FileDescriptor}.
* The {@code offset} is the offset for the {@link FileDescriptor} and {@code len} is the
* number of bytes to splice. If using {@link Integer#MAX_VALUE} it will splice until the
* {@link ChannelFuture} was canceled or it was failed.
*
* Please note:
* <ul>
* <li>{@link EpollChannelConfig#getEpollMode()} must be {@link EpollMode#LEVEL_TRIGGERED} for this
* {@link AbstractEpollStreamChannel}</li>
* <li>the {@link FileDescriptor} will not be closed after the {@link ChannelPromise} is notified</li>
* <li>this channel must be registered to an event loop or {@link IllegalStateException} will be thrown.</li>
* </ul>
*/
public final ChannelFuture spliceTo(final FileDescriptor ch, final int offset, final int len,
final ChannelPromise promise) {
checkPositiveOrZero(len, "len");
checkPositiveOrZero(offset, "offset");
if (config().getEpollMode() != EpollMode.LEVEL_TRIGGERED) {
throw new IllegalStateException("spliceTo() supported only when using " + EpollMode.LEVEL_TRIGGERED);
}
checkNotNull(promise, "promise");
if (!isOpen()) {
promise.tryFailure(new ClosedChannelException());
} else {
addToSpliceQueue(new SpliceFdTask(ch, offset, len, promise));
failSpliceIfClosed(promise);
}
return promise;
}
private void failSpliceIfClosed(ChannelPromise promise) {
if (!isOpen()) {
// Seems like the Channel was closed in the meantime try to fail the promise to prevent any
// cases where a future may not be notified otherwise.
if (!promise.isDone()) {
final ClosedChannelException ex = new ClosedChannelException();
if (promise.tryFailure(ex)) {
eventLoop().execute(new Runnable() {
@Override
public void run() {
// Call this via the EventLoop as it is a MPSC queue.
clearSpliceQueue(ex);
}
});
}
}
}
}
/**
* Write bytes form the given {@link ByteBuf} to the underlying {@link java.nio.channels.Channel}.
* @param in the collection which contains objects to write.
* @param buf the {@link ByteBuf} from which the bytes should be written
* @return The value that should be decremented from the write quantum which starts at
* {@link ChannelConfig#getWriteSpinCount()}. The typical use cases are as follows:
* <ul>
* <li>0 - if no write was attempted. This is appropriate if an empty {@link ByteBuf} (or other empty content)
* is encountered</li>
* <li>1 - if a single call to write data was made to the OS</li>
* <li>{@link ChannelUtils#WRITE_STATUS_SNDBUF_FULL} - if an attempt to write data was made to the OS, but
* no data was accepted</li>
* </ul>
*/
private int writeBytes(ChannelOutboundBuffer in, ByteBuf buf) throws Exception {
int readableBytes = buf.readableBytes();
if (readableBytes == 0) {
in.remove();
return 0;
}
if (buf.hasMemoryAddress() || buf.nioBufferCount() == 1) {
return doWriteBytes(in, buf);
} else {
ByteBuffer[] nioBuffers = buf.nioBuffers();
return writeBytesMultiple(in, nioBuffers, nioBuffers.length, readableBytes,
config().getMaxBytesPerGatheringWrite());
}
}
private void adjustMaxBytesPerGatheringWrite(long attempted, long written, long oldMaxBytesPerGatheringWrite) {
// By default we track the SO_SNDBUF when ever it is explicitly set. However some OSes may dynamically change
// SO_SNDBUF (and other characteristics that determine how much data can be written at once) so we should try
// make a best effort to adjust as OS behavior changes.
if (attempted == written) {
if (attempted << 1 > oldMaxBytesPerGatheringWrite) {
config().setMaxBytesPerGatheringWrite(attempted << 1);
}
} else if (attempted > MAX_BYTES_PER_GATHERING_WRITE_ATTEMPTED_LOW_THRESHOLD && written < attempted >>> 1) {
config().setMaxBytesPerGatheringWrite(attempted >>> 1);
}
}
/**
* Write multiple bytes via {@link IovArray}.
* @param in the collection which contains objects to write.
* @param array The array which contains the content 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:
* <ul>
* <li>0 - if no write was attempted. This is appropriate if an empty {@link ByteBuf} (or other empty content)
* is encountered</li>
* <li>1 - if a single call to write data was made to the OS</li>
* <li>{@link ChannelUtils#WRITE_STATUS_SNDBUF_FULL} - if an attempt to write data was made to the OS, but
* no data was accepted</li>
* </ul>
* @throws IOException If an I/O exception occurs during write.
*/
private int writeBytesMultiple(ChannelOutboundBuffer in, IovArray array) throws IOException {
final long expectedWrittenBytes = array.size();
assert expectedWrittenBytes != 0;
final int cnt = array.count();
assert cnt != 0;
final long localWrittenBytes = socket.writevAddresses(array.memoryAddress(0), cnt);
if (localWrittenBytes > 0) {
adjustMaxBytesPerGatheringWrite(expectedWrittenBytes, localWrittenBytes, array.maxBytes());
in.removeBytes(localWrittenBytes);
return 1;
}
return WRITE_STATUS_SNDBUF_FULL;
}
/**
* Write multiple bytes via {@link ByteBuffer} array.
* @param in the collection which contains objects to write.
* @param nioBuffers The buffers to write.
* @param nioBufferCnt The number of buffers to write.
* @param expectedWrittenBytes The number of bytes we expect to write.
* @param maxBytesPerGatheringWrite The maximum number of bytes we should attempt 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:
* <ul>
* <li>0 - if no write was attempted. This is appropriate if an empty {@link ByteBuf} (or other empty content)
* is encountered</li>
* <li>1 - if a single call to write data was made to the OS</li>
* <li>{@link ChannelUtils#WRITE_STATUS_SNDBUF_FULL} - if an attempt to write data was made to the OS, but
* no data was accepted</li>
* </ul>
* @throws IOException If an I/O exception occurs during write.
*/
private int writeBytesMultiple(
ChannelOutboundBuffer in, ByteBuffer[] nioBuffers, int nioBufferCnt, long expectedWrittenBytes,
long maxBytesPerGatheringWrite) throws IOException {
assert expectedWrittenBytes != 0;
if (expectedWrittenBytes > maxBytesPerGatheringWrite) {
expectedWrittenBytes = maxBytesPerGatheringWrite;
}
final long localWrittenBytes = socket.writev(nioBuffers, 0, nioBufferCnt, expectedWrittenBytes);
if (localWrittenBytes > 0) {
adjustMaxBytesPerGatheringWrite(expectedWrittenBytes, localWrittenBytes, maxBytesPerGatheringWrite);
in.removeBytes(localWrittenBytes);
return 1;
}
return WRITE_STATUS_SNDBUF_FULL;
}
/**
* Write a {@link DefaultFileRegion}
* @param in the collection which contains objects to write.
* @param region the {@link DefaultFileRegion} from which the bytes should be written
* @return The value that should be decremented from the write quantum which starts at
* {@link ChannelConfig#getWriteSpinCount()}. The typical use cases are as follows:
* <ul>
* <li>0 - if no write was attempted. This is appropriate if an empty {@link ByteBuf} (or other empty content)
* is encountered</li>
* <li>1 - if a single call to write data was made to the OS</li>
* <li>{@link ChannelUtils#WRITE_STATUS_SNDBUF_FULL} - if an attempt to write data was made to the OS, but
* no data was accepted</li>
* </ul>
*/
private int writeDefaultFileRegion(ChannelOutboundBuffer in, DefaultFileRegion region) throws Exception {
final long offset = region.transferred();
final long regionCount = region.count();
if (offset >= regionCount) {
in.remove();
return 0;
}
final long flushedAmount = socket.sendFile(region, region.position(), offset, regionCount - offset);
if (flushedAmount > 0) {
in.progress(flushedAmount);
if (region.transferred() >= regionCount) {
in.remove();
}
return 1;
} else if (flushedAmount == 0) {
validateFileRegion(region, offset);
}
return WRITE_STATUS_SNDBUF_FULL;
}
/**
* Write a {@link FileRegion}
* @param in the collection which contains objects to write.
* @param region the {@link FileRegion} from which the bytes should be written
* @return The value that should be decremented from the write quantum which starts at
* {@link ChannelConfig#getWriteSpinCount()}. The typical use cases are as follows:
* <ul>
* <li>0 - if no write was attempted. This is appropriate if an empty {@link ByteBuf} (or other empty content)
* is encountered</li>
* <li>1 - if a single call to write data was made to the OS</li>
* <li>{@link ChannelUtils#WRITE_STATUS_SNDBUF_FULL} - if an attempt to write data was made to the OS, but
* no data was accepted</li>
* </ul>
*/
private int writeFileRegion(ChannelOutboundBuffer in, FileRegion region) throws Exception {
if (region.transferred() >= region.count()) {
in.remove();
return 0;
}
if (byteChannel == null) {
byteChannel = new EpollSocketWritableByteChannel();
}
final long flushedAmount = region.transferTo(byteChannel, region.transferred());
if (flushedAmount > 0) {
in.progress(flushedAmount);
if (region.transferred() >= region.count()) {
in.remove();
}
return 1;
}
return WRITE_STATUS_SNDBUF_FULL;
}
@Override
protected void doWrite(ChannelOutboundBuffer in) throws Exception {
int writeSpinCount = config().getWriteSpinCount();
do {
final int msgCount = in.size();
// Do gathering write if the outbound buffer entries start with more than one ByteBuf.
if (msgCount > 1 && in.current() instanceof ByteBuf) {
writeSpinCount -= doWriteMultiple(in);
} else if (msgCount == 0) {
// Wrote all messages.
clearFlag(Native.EPOLLOUT);
// Return here so we not set the EPOLLOUT flag.
return;
} else { // msgCount == 1
writeSpinCount -= doWriteSingle(in);
}
// We do not break the loop here even if the outbound buffer was flushed completely,
// because a user might have triggered another write and flush when we notify his or her
// listeners.
} while (writeSpinCount > 0);
if (writeSpinCount == 0) {
// It is possible that we have set EPOLLOUT, woken up by EPOLL because the socket is writable, and then use
// our write quantum. In this case we no longer want to set the EPOLLOUT flag 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 EPOLLOUT if necessary.
clearFlag(Native.EPOLLOUT);
// We used our writeSpin quantum, and should try to write again later.
eventLoop().execute(flushTask);
} else {
// Underlying descriptor can not accept all data currently, so set the EPOLLOUT flag to be woken up
// when it can accept more data.
setFlag(Native.EPOLLOUT);
}
}
/**
* Attempt to write a single object.
* @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:
* <ul>
* <li>0 - if no write was attempted. This is appropriate if an empty {@link ByteBuf} (or other empty content)
* is encountered</li>
* <li>1 - if a single call to write data was made to the OS</li>
* <li>{@link ChannelUtils#WRITE_STATUS_SNDBUF_FULL} - if an attempt to write data was made to the OS, but
* no data was accepted</li>
* </ul>
* @throws Exception If an I/O error occurs.
*/
protected int doWriteSingle(ChannelOutboundBuffer in) throws Exception {
// The outbound buffer contains only one message or it contains a file region.
Object msg = in.current();
if (msg instanceof ByteBuf) {
return writeBytes(in, (ByteBuf) msg);
} else if (msg instanceof DefaultFileRegion) {
return writeDefaultFileRegion(in, (DefaultFileRegion) msg);
} else if (msg instanceof FileRegion) {
return writeFileRegion(in, (FileRegion) msg);
} else if (msg instanceof SpliceOutTask) {
if (!((SpliceOutTask) msg).spliceOut()) {
return WRITE_STATUS_SNDBUF_FULL;
}
in.remove();
return 1;
} else {
// Should never reach here.
throw new Error();
}
}
/**
* Attempt to write multiple {@link ByteBuf} objects.
* @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:
* <ul>
* <li>0 - if no write was attempted. This is appropriate if an empty {@link ByteBuf} (or other empty content)
* is encountered</li>
* <li>1 - if a single call to write data was made to the OS</li>
* <li>{@link ChannelUtils#WRITE_STATUS_SNDBUF_FULL} - if an attempt to write data was made to the OS, but
* no data was accepted</li>
* </ul>
* @throws Exception If an I/O error occurs.
*/
private int doWriteMultiple(ChannelOutboundBuffer in) throws Exception {
final long maxBytesPerGatheringWrite = config().getMaxBytesPerGatheringWrite();
IovArray array = ((EpollEventLoop) eventLoop()).cleanIovArray();
array.maxBytes(maxBytesPerGatheringWrite);
in.forEachFlushedMessage(array);
if (array.count() >= 1) {
// TODO: Handle the case where cnt == 1 specially.
return writeBytesMultiple(in, array);
}
// cnt == 0, which means the outbound buffer contained empty buffers only.
in.removeBytes(0);
return 0;
}
@Override
protected Object filterOutboundMessage(Object msg) {
if (msg instanceof ByteBuf) {
ByteBuf buf = (ByteBuf) msg;
return UnixChannelUtil.isBufferCopyNeededForWrite(buf)? newDirectBuffer(buf): buf;
}
if (msg instanceof FileRegion || msg instanceof SpliceOutTask) {
return msg;
}
throw new UnsupportedOperationException(
"unsupported message type: " + StringUtil.simpleClassName(msg) + EXPECTED_TYPES);
}
@UnstableApi
@Override
protected final void doShutdownOutput() throws Exception {
socket.shutdown(false, true);
}
private void shutdownInput0(final ChannelPromise promise) {
try {
socket.shutdown(true, false);
promise.setSuccess();
} catch (Throwable cause) {
promise.setFailure(cause);
}
}
@Override
public boolean isOutputShutdown() {
return socket.isOutputShutdown();
}
@Override
public boolean isInputShutdown() {
return socket.isInputShutdown();
}
@Override
public boolean isShutdown() {
return socket.isShutdown();
}
@Override
public ChannelFuture shutdownOutput() {
return shutdownOutput(newPromise());
}
@Override
public ChannelFuture shutdownOutput(final ChannelPromise promise) {
EventLoop loop = eventLoop();
if (loop.inEventLoop()) {
((AbstractUnsafe) unsafe()).shutdownOutput(promise);
} else {
loop.execute(new Runnable() {
@Override
public void run() {
((AbstractUnsafe) unsafe()).shutdownOutput(promise);
}
});
}
return promise;
}
@Override
public ChannelFuture shutdownInput() {
return shutdownInput(newPromise());
}
@Override
public ChannelFuture shutdownInput(final ChannelPromise promise) {
Executor closeExecutor = ((EpollStreamUnsafe) unsafe()).prepareToClose();
if (closeExecutor != null) {
closeExecutor.execute(new Runnable() {
@Override
public void run() {
shutdownInput0(promise);
}
});
} else {
EventLoop loop = eventLoop();
if (loop.inEventLoop()) {
shutdownInput0(promise);
} else {
loop.execute(new Runnable() {
@Override
public void run() {
shutdownInput0(promise);
}
});
}
}
return promise;
}
@Override
public ChannelFuture shutdown() {
return shutdown(newPromise());
}
@Override
public ChannelFuture shutdown(final ChannelPromise promise) {
ChannelFuture shutdownOutputFuture = shutdownOutput();
if (shutdownOutputFuture.isDone()) {
shutdownOutputDone(shutdownOutputFuture, promise);
} else {
shutdownOutputFuture.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(final ChannelFuture shutdownOutputFuture) throws Exception {
shutdownOutputDone(shutdownOutputFuture, promise);
}
});
}
return promise;
}
private void shutdownOutputDone(final ChannelFuture shutdownOutputFuture, final ChannelPromise promise) {
ChannelFuture shutdownInputFuture = shutdownInput();
if (shutdownInputFuture.isDone()) {
shutdownDone(shutdownOutputFuture, shutdownInputFuture, promise);
} else {
shutdownInputFuture.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture shutdownInputFuture) throws Exception {
shutdownDone(shutdownOutputFuture, shutdownInputFuture, promise);
}
});
}
}
private static void shutdownDone(ChannelFuture shutdownOutputFuture,
ChannelFuture shutdownInputFuture,
ChannelPromise promise) {
Throwable shutdownOutputCause = shutdownOutputFuture.cause();
Throwable shutdownInputCause = shutdownInputFuture.cause();
if (shutdownOutputCause != null) {
if (shutdownInputCause != null) {
logger.debug("Exception suppressed because a previous exception occurred.",
shutdownInputCause);
}
promise.setFailure(shutdownOutputCause);
} else if (shutdownInputCause != null) {
promise.setFailure(shutdownInputCause);
} else {
promise.setSuccess();
}
}
@Override
protected void doClose() throws Exception {
try {
// Calling super.doClose() first so spliceTo(...) will fail on next call.
super.doClose();
} finally {
safeClosePipe(pipeIn);
safeClosePipe(pipeOut);
clearSpliceQueue(null);
}
}
private void clearSpliceQueue(ClosedChannelException exception) {
Queue<SpliceInTask> sQueue = spliceQueue;
if (sQueue == null) {
return;
}
for (;;) {
SpliceInTask task = sQueue.poll();
if (task == null) {
break;
}
if (exception == null) {
exception = new ClosedChannelException();
}
task.promise.tryFailure(exception);
}
}
private static void safeClosePipe(FileDescriptor fd) {
if (fd != null) {
try {
fd.close();
} catch (IOException e) {
logger.warn("Error while closing a pipe", e);
}
}
}
class EpollStreamUnsafe extends AbstractEpollUnsafe {
// Overridden here just to be able to access this method from AbstractEpollStreamChannel
@Override
protected Executor prepareToClose() {
return super.prepareToClose();
}
private void handleReadException(ChannelPipeline pipeline, ByteBuf byteBuf, Throwable cause, boolean close,
EpollRecvByteAllocatorHandle 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) {
shutdownInput(false);
}
}
@Override
EpollRecvByteAllocatorHandle newEpollHandle(RecvByteBufAllocator.ExtendedHandle handle) {
return new EpollRecvByteAllocatorStreamingHandle(handle);
}
@Override
void epollInReady() {
final ChannelConfig config = config();
if (shouldBreakEpollInReady(config)) {
clearEpollIn0();
return;
}
final EpollRecvByteAllocatorHandle allocHandle = recvBufAllocHandle();
allocHandle.edgeTriggered(isFlagSet(Native.EPOLLET));
final ChannelPipeline pipeline = pipeline();
final ByteBufAllocator allocator = config.getAllocator();
allocHandle.reset(config);
epollInBefore();
ByteBuf byteBuf = null;
boolean close = false;
Queue<SpliceInTask> sQueue = null;
try {
do {
if (sQueue != null || (sQueue = spliceQueue) != null) {
SpliceInTask spliceTask = sQueue.peek();
if (spliceTask != null) {
boolean spliceInResult = spliceTask.spliceIn(allocHandle);
if (allocHandle.isReceivedRdHup()) {
shutdownInput(true);
}
if (spliceInResult) {
// We need to check if it is still active as if not we removed all SpliceTasks in
// doClose(...)
if (isActive()) {
sQueue.remove();
}
continue;
} else {
break;
}
}
}
// we use a direct buffer here as the native implementations only be able
// to handle direct buffers.
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;
if (shouldBreakEpollInReady(config)) {
// We need to do this for two reasons:
//
// - If the input was shutdown in between (which may be the case when the user did it in the
// fireChannelRead(...) method we should not try to read again to not produce any
// miss-leading exceptions.
//
// - If the user closes the channel we need to ensure we not try to read from it again as
// the filedescriptor may be re-used already by the OS if the system is handling a lot of
// concurrent connections and so needs a lot of filedescriptors. If not do this we risk
// reading data from a filedescriptor that belongs to another socket then the socket that
// was "wrapped" by this Channel implementation.
break;
}
} while (allocHandle.continueReading());
allocHandle.readComplete();
pipeline.fireChannelReadComplete();
if (close) {
shutdownInput(false);
}
} catch (Throwable t) {
handleReadException(pipeline, byteBuf, t, close, allocHandle);
} finally {
if (sQueue == null) {
epollInFinally(config);
} else {
if (!config.isAutoRead()) {
clearEpollIn();
}
}
}
}
}
private void addToSpliceQueue(final SpliceInTask task) {
Queue<SpliceInTask> sQueue = spliceQueue;
if (sQueue == null) {
synchronized (this) {
sQueue = spliceQueue;
if (sQueue == null) {
spliceQueue = sQueue = PlatformDependent.newMpscQueue();
}
}
}
sQueue.add(task);
}
protected abstract class SpliceInTask {
final ChannelPromise promise;
int len;
protected SpliceInTask(int len, ChannelPromise promise) {
this.promise = promise;
this.len = len;
}
abstract boolean spliceIn(RecvByteBufAllocator.Handle handle);
protected final int spliceIn(FileDescriptor pipeOut, RecvByteBufAllocator.Handle handle) throws IOException {
// calculate the maximum amount of data we are allowed to splice
int length = Math.min(handle.guess(), len);
int splicedIn = 0;
for (;;) {
// Splicing until there is nothing left to splice.
int localSplicedIn = Native.splice(socket.intValue(), -1, pipeOut.intValue(), -1, length);
handle.lastBytesRead(localSplicedIn);
if (localSplicedIn == 0) {
break;
}
splicedIn += localSplicedIn;
length -= localSplicedIn;
}
return splicedIn;
}
}
// Let it directly implement channelFutureListener as well to reduce object creation.
private final class SpliceInChannelTask extends SpliceInTask implements ChannelFutureListener {
private final AbstractEpollStreamChannel ch;
SpliceInChannelTask(AbstractEpollStreamChannel ch, int len, ChannelPromise promise) {
super(len, promise);
this.ch = ch;
}
@Override
public void operationComplete(ChannelFuture future) throws Exception {
if (!future.isSuccess()) {
// Use tryFailure(...) as the promise might already be closed by spliceTo(...)
promise.tryFailure(future.cause());
}
}
@Override
public boolean spliceIn(RecvByteBufAllocator.Handle handle) {
assert ch.eventLoop().inEventLoop();
if (len == 0) {
// Use trySuccess() as the promise might already be closed by spliceTo(...)
promise.trySuccess();
return true;
}
try {
// We create the pipe on the target channel as this will allow us to just handle pending writes
// later in a correct fashion without get into any ordering issues when spliceTo(...) is called
// on multiple Channels pointing to one target Channel.
FileDescriptor pipeOut = ch.pipeOut;
if (pipeOut == null) {
// Create a new pipe as non was created before.
FileDescriptor[] pipe = pipe();
ch.pipeIn = pipe[0];
pipeOut = ch.pipeOut = pipe[1];
}
int splicedIn = spliceIn(pipeOut, handle);
if (splicedIn > 0) {
// Integer.MAX_VALUE is a special value which will result in splice forever.
if (len != Integer.MAX_VALUE) {
len -= splicedIn;
}
// Depending on if we are done with splicing inbound data we set the right promise for the
// outbound splicing.
final ChannelPromise splicePromise;
if (len == 0) {
splicePromise = promise;
} else {
splicePromise = ch.newPromise().addListener(this);
}
boolean autoRead = config().isAutoRead();
// Just call unsafe().write(...) and flush() as we not want to traverse the whole pipeline for this
// case.
ch.unsafe().write(new SpliceOutTask(ch, splicedIn, autoRead), splicePromise);
ch.unsafe().flush();
if (autoRead && !splicePromise.isDone()) {
// Write was not done which means the target channel was not writable. In this case we need to
// disable reading until we are done with splicing to the target channel because:
//
// - The user may want to trigger another splice operation once the splicing was complete.
config().setAutoRead(false);
}
}
return len == 0;
} catch (Throwable cause) {
// Use tryFailure(...) as the promise might already be closed by spliceTo(...)
promise.tryFailure(cause);
return true;
}
}
}
private final class SpliceOutTask {
private final AbstractEpollStreamChannel ch;
private final boolean autoRead;
private int len;
SpliceOutTask(AbstractEpollStreamChannel ch, int len, boolean autoRead) {
this.ch = ch;
this.len = len;
this.autoRead = autoRead;
}
public boolean spliceOut() throws Exception {
assert ch.eventLoop().inEventLoop();
try {
int splicedOut = Native.splice(ch.pipeIn.intValue(), -1, ch.socket.intValue(), -1, len);
len -= splicedOut;
if (len == 0) {
if (autoRead) {
// AutoRead was used and we spliced everything so start reading again
config().setAutoRead(true);
}
return true;
}
return false;
} catch (IOException e) {
if (autoRead) {
// AutoRead was used and we spliced everything so start reading again
config().setAutoRead(true);
}
throw e;
}
}
}
private final class SpliceFdTask extends SpliceInTask {
private final FileDescriptor fd;
private final ChannelPromise promise;
private int offset;
SpliceFdTask(FileDescriptor fd, int offset, int len, ChannelPromise promise) {
super(len, promise);
this.fd = fd;
this.promise = promise;
this.offset = offset;
}
@Override
public boolean spliceIn(RecvByteBufAllocator.Handle handle) {
assert eventLoop().inEventLoop();
if (len == 0) {
// Use trySuccess() as the promise might already be failed by spliceTo(...)
promise.trySuccess();
return true;
}
try {
FileDescriptor[] pipe = pipe();
FileDescriptor pipeIn = pipe[0];
FileDescriptor pipeOut = pipe[1];
try {
int splicedIn = spliceIn(pipeOut, handle);
if (splicedIn > 0) {
// Integer.MAX_VALUE is a special value which will result in splice forever.
if (len != Integer.MAX_VALUE) {
len -= splicedIn;
}
do {
int splicedOut = Native.splice(pipeIn.intValue(), -1, fd.intValue(), offset, splicedIn);
offset += splicedOut;
splicedIn -= splicedOut;
} while (splicedIn > 0);
if (len == 0) {
// Use trySuccess() as the promise might already be failed by spliceTo(...)
promise.trySuccess();
return true;
}
}
return false;
} finally {
safeClosePipe(pipeIn);
safeClosePipe(pipeOut);
}
} catch (Throwable cause) {
// Use tryFailure(...) as the promise might already be failed by spliceTo(...)
promise.tryFailure(cause);
return true;
}
}
}
private final class EpollSocketWritableByteChannel extends SocketWritableByteChannel {
EpollSocketWritableByteChannel() {
super(socket);
assert fd == socket;
}
@Override
protected int write(final ByteBuffer buf, final int pos, final int limit) throws IOException {
return socket.send(buf, pos, limit);
}
@Override
protected ByteBufAllocator alloc() {
return AbstractEpollStreamChannel.this.alloc();
}
}
}