io.netty.channel.ChannelOutboundBuffer 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 2013 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:
*
* 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 io.netty.channel;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufHolder;
import io.netty.buffer.Unpooled;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.util.Recycler;
import io.netty.util.Recycler.Handle;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.concurrent.FastThreadLocal;
import io.netty.util.internal.InternalThreadLocalMap;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
import java.util.concurrent.atomic.AtomicLongFieldUpdater;
/**
* (Transport implementors only) an internal data structure used by {@link AbstractChannel} to store its pending
* outbound write requests.
*
* All methods must be called by a transport implementation from an I/O thread, except the following ones:
*
* - {@link #size()} and {@link #isEmpty()}
* - {@link #isWritable()}
* - {@link #getUserDefinedWritability(int)} and {@link #setUserDefinedWritability(int, boolean)}
*
*
*/
public final class ChannelOutboundBuffer {
private static final InternalLogger logger = InternalLoggerFactory.getInstance(ChannelOutboundBuffer.class);
private static final FastThreadLocal NIO_BUFFERS = new FastThreadLocal() {
@Override
protected ByteBuffer[] initialValue() throws Exception {
return new ByteBuffer[1024];
}
};
private final Channel channel;
// Entry(flushedEntry) --> ... Entry(unflushedEntry) --> ... Entry(tailEntry)
//
// The Entry that is the first in the linked-list structure that was flushed
private Entry flushedEntry;
// The Entry which is the first unflushed in the linked-list structure
private Entry unflushedEntry;
// The Entry which represents the tail of the buffer
private Entry tailEntry;
// The number of flushed entries that are not written yet
private int flushed;
private int nioBufferCount;
private long nioBufferSize;
private boolean inFail;
private static final AtomicLongFieldUpdater TOTAL_PENDING_SIZE_UPDATER;
@SuppressWarnings("UnusedDeclaration")
private volatile long totalPendingSize;
private static final AtomicIntegerFieldUpdater UNWRITABLE_UPDATER;
@SuppressWarnings("UnusedDeclaration")
private volatile int unwritable;
private volatile Runnable fireChannelWritabilityChangedTask;
static {
AtomicIntegerFieldUpdater unwritableUpdater =
PlatformDependent.newAtomicIntegerFieldUpdater(ChannelOutboundBuffer.class, "unwritable");
if (unwritableUpdater == null) {
unwritableUpdater = AtomicIntegerFieldUpdater.newUpdater(ChannelOutboundBuffer.class, "unwritable");
}
UNWRITABLE_UPDATER = unwritableUpdater;
AtomicLongFieldUpdater pendingSizeUpdater =
PlatformDependent.newAtomicLongFieldUpdater(ChannelOutboundBuffer.class, "totalPendingSize");
if (pendingSizeUpdater == null) {
pendingSizeUpdater = AtomicLongFieldUpdater.newUpdater(ChannelOutboundBuffer.class, "totalPendingSize");
}
TOTAL_PENDING_SIZE_UPDATER = pendingSizeUpdater;
}
ChannelOutboundBuffer(AbstractChannel channel) {
this.channel = channel;
}
/**
* Add given message to this {@link ChannelOutboundBuffer}. The given {@link ChannelPromise} will be notified once
* the message was written.
*/
public void addMessage(Object msg, int size, ChannelPromise promise) {
Entry entry = Entry.newInstance(msg, size, total(msg), promise);
if (tailEntry == null) {
flushedEntry = null;
tailEntry = entry;
} else {
Entry tail = tailEntry;
tail.next = entry;
tailEntry = entry;
}
if (unflushedEntry == null) {
unflushedEntry = entry;
}
// increment pending bytes after adding message to the unflushed arrays.
// See https://github.com/netty/netty/issues/1619
incrementPendingOutboundBytes(size, false);
}
/**
* Add a flush to this {@link ChannelOutboundBuffer}. This means all previous added messages are marked as flushed
* and so you will be able to handle them.
*/
public void addFlush() {
// There is no need to process all entries if there was already a flush before and no new messages
// where added in the meantime.
//
// See https://github.com/netty/netty/issues/2577
Entry entry = unflushedEntry;
if (entry != null) {
if (flushedEntry == null) {
// there is no flushedEntry yet, so start with the entry
flushedEntry = entry;
}
do {
flushed ++;
if (!entry.promise.setUncancellable()) {
// Was cancelled so make sure we free up memory and notify about the freed bytes
int pending = entry.cancel();
decrementPendingOutboundBytes(pending, false);
}
entry = entry.next;
} while (entry != null);
// All flushed so reset unflushedEntry
unflushedEntry = null;
}
}
/**
* Increment the pending bytes which will be written at some point.
* This method is thread-safe!
*/
void incrementPendingOutboundBytes(long size) {
incrementPendingOutboundBytes(size, true);
}
private void incrementPendingOutboundBytes(long size, boolean invokeLater) {
if (size == 0) {
return;
}
long newWriteBufferSize = TOTAL_PENDING_SIZE_UPDATER.addAndGet(this, size);
if (newWriteBufferSize >= channel.config().getWriteBufferHighWaterMark()) {
setUnwritable(invokeLater);
}
}
/**
* Decrement the pending bytes which will be written at some point.
* This method is thread-safe!
*/
void decrementPendingOutboundBytes(long size) {
decrementPendingOutboundBytes(size, true);
}
private void decrementPendingOutboundBytes(long size, boolean invokeLater) {
if (size == 0) {
return;
}
long newWriteBufferSize = TOTAL_PENDING_SIZE_UPDATER.addAndGet(this, -size);
if (newWriteBufferSize == 0 || newWriteBufferSize <= channel.config().getWriteBufferLowWaterMark()) {
setWritable(invokeLater);
}
}
private static long total(Object msg) {
if (msg instanceof ByteBuf) {
return ((ByteBuf) msg).readableBytes();
}
if (msg instanceof FileRegion) {
return ((FileRegion) msg).count();
}
if (msg instanceof ByteBufHolder) {
return ((ByteBufHolder) msg).content().readableBytes();
}
return -1;
}
/**
* Return the current message to write or {@code null} if nothing was flushed before and so is ready to be written.
*/
public Object current() {
Entry entry = flushedEntry;
if (entry == null) {
return null;
}
return entry.msg;
}
/**
* Notify the {@link ChannelPromise} of the current message about writing progress.
*/
public void progress(long amount) {
Entry e = flushedEntry;
assert e != null;
ChannelPromise p = e.promise;
if (p instanceof ChannelProgressivePromise) {
long progress = e.progress + amount;
e.progress = progress;
((ChannelProgressivePromise) p).tryProgress(progress, e.total);
}
}
/**
* Will remove the current message, mark its {@link ChannelPromise} as success and return {@code true}. If no
* flushed message exists at the time this method is called it will return {@code false} to signal that no more
* messages are ready to be handled.
*/
public boolean remove() {
Entry e = flushedEntry;
if (e == null) {
return false;
}
Object msg = e.msg;
ChannelPromise promise = e.promise;
int size = e.pendingSize;
removeEntry(e);
if (!e.cancelled) {
// only release message, notify and decrement if it was not canceled before.
ReferenceCountUtil.safeRelease(msg);
safeSuccess(promise);
decrementPendingOutboundBytes(size, false);
}
// recycle the entry
e.recycle();
return true;
}
/**
* Will remove the current message, mark its {@link ChannelPromise} as failure using the given {@link Throwable}
* and return {@code true}. If no flushed message exists at the time this method is called it will return
* {@code false} to signal that no more messages are ready to be handled.
*/
public boolean remove(Throwable cause) {
Entry e = flushedEntry;
if (e == null) {
return false;
}
Object msg = e.msg;
ChannelPromise promise = e.promise;
int size = e.pendingSize;
removeEntry(e);
if (!e.cancelled) {
// only release message, fail and decrement if it was not canceled before.
ReferenceCountUtil.safeRelease(msg);
safeFail(promise, cause);
decrementPendingOutboundBytes(size, false);
}
// recycle the entry
e.recycle();
return true;
}
private void removeEntry(Entry e) {
if (-- flushed == 0) {
// processed everything
flushedEntry = null;
if (e == tailEntry) {
tailEntry = null;
unflushedEntry = null;
}
} else {
flushedEntry = e.next;
}
}
/**
* Removes the fully written entries and update the reader index of the partially written entry.
* This operation assumes all messages in this buffer is {@link ByteBuf}.
*/
public void removeBytes(long writtenBytes) {
for (;;) {
Object msg = current();
if (!(msg instanceof ByteBuf)) {
assert writtenBytes == 0;
break;
}
final ByteBuf buf = (ByteBuf) msg;
final int readerIndex = buf.readerIndex();
final int readableBytes = buf.writerIndex() - readerIndex;
if (readableBytes <= writtenBytes) {
if (writtenBytes != 0) {
progress(readableBytes);
writtenBytes -= readableBytes;
}
remove();
} else { // readableBytes > writtenBytes
if (writtenBytes != 0) {
buf.readerIndex(readerIndex + (int) writtenBytes);
progress(writtenBytes);
}
break;
}
}
}
/**
* Returns an array of direct NIO buffers if the currently pending messages are made of {@link ByteBuf} only.
* {@link #nioBufferCount()} and {@link #nioBufferSize()} will return the number of NIO buffers in the returned
* array and the total number of readable bytes of the NIO buffers respectively.
*
* Note that the returned array is reused and thus should not escape
* {@link AbstractChannel#doWrite(ChannelOutboundBuffer)}.
* Refer to {@link NioSocketChannel#doWrite(ChannelOutboundBuffer)} for an example.
*
*/
public ByteBuffer[] nioBuffers() {
long nioBufferSize = 0;
int nioBufferCount = 0;
final InternalThreadLocalMap threadLocalMap = InternalThreadLocalMap.get();
ByteBuffer[] nioBuffers = NIO_BUFFERS.get(threadLocalMap);
Entry entry = flushedEntry;
while (isFlushedEntry(entry) && entry.msg instanceof ByteBuf) {
if (!entry.cancelled) {
ByteBuf buf = (ByteBuf) entry.msg;
final int readerIndex = buf.readerIndex();
final int readableBytes = buf.writerIndex() - readerIndex;
if (readableBytes > 0) {
nioBufferSize += readableBytes;
int count = entry.count;
if (count == -1) {
//noinspection ConstantValueVariableUse
entry.count = count = buf.nioBufferCount();
}
int neededSpace = nioBufferCount + count;
if (neededSpace > nioBuffers.length) {
nioBuffers = expandNioBufferArray(nioBuffers, neededSpace, nioBufferCount);
NIO_BUFFERS.set(threadLocalMap, nioBuffers);
}
if (count == 1) {
ByteBuffer nioBuf = entry.buf;
if (nioBuf == null) {
// cache ByteBuffer as it may need to create a new ByteBuffer instance if its a
// derived buffer
entry.buf = nioBuf = buf.internalNioBuffer(readerIndex, readableBytes);
}
nioBuffers[nioBufferCount ++] = nioBuf;
} else {
ByteBuffer[] nioBufs = entry.bufs;
if (nioBufs == null) {
// cached ByteBuffers as they may be expensive to create in terms
// of Object allocation
entry.bufs = nioBufs = buf.nioBuffers();
}
nioBufferCount = fillBufferArray(nioBufs, nioBuffers, nioBufferCount);
}
}
}
entry = entry.next;
}
this.nioBufferCount = nioBufferCount;
this.nioBufferSize = nioBufferSize;
return nioBuffers;
}
private static int fillBufferArray(ByteBuffer[] nioBufs, ByteBuffer[] nioBuffers, int nioBufferCount) {
for (ByteBuffer nioBuf: nioBufs) {
if (nioBuf == null) {
break;
}
nioBuffers[nioBufferCount ++] = nioBuf;
}
return nioBufferCount;
}
private static ByteBuffer[] expandNioBufferArray(ByteBuffer[] array, int neededSpace, int size) {
int newCapacity = array.length;
do {
// double capacity until it is big enough
// See https://github.com/netty/netty/issues/1890
newCapacity <<= 1;
if (newCapacity < 0) {
throw new IllegalStateException();
}
} while (neededSpace > newCapacity);
ByteBuffer[] newArray = new ByteBuffer[newCapacity];
System.arraycopy(array, 0, newArray, 0, size);
return newArray;
}
/**
* Returns the number of {@link ByteBuffer} that can be written out of the {@link ByteBuffer} array that was
* obtained via {@link #nioBuffers()}. This method MUST be called after {@link #nioBuffers()}
* was called.
*/
public int nioBufferCount() {
return nioBufferCount;
}
/**
* Returns the number of bytes that can be written out of the {@link ByteBuffer} array that was
* obtained via {@link #nioBuffers()}. This method MUST be called after {@link #nioBuffers()}
* was called.
*/
public long nioBufferSize() {
return nioBufferSize;
}
/**
* Returns {@code true} if and only if {@linkplain #totalPendingWriteBytes() the total number of pending bytes} did
* not exceed the write watermark of the {@link Channel} and
* no {@linkplain #setUserDefinedWritability(int, boolean) user-defined writability flag} has been set to
* {@code false}.
*/
public boolean isWritable() {
return unwritable == 0;
}
/**
* Returns {@code true} if and only if the user-defined writability flag at the specified index is set to
* {@code true}.
*/
public boolean getUserDefinedWritability(int index) {
return (unwritable & writabilityMask(index)) == 0;
}
/**
* Sets a user-defined writability flag at the specified index.
*/
public void setUserDefinedWritability(int index, boolean writable) {
if (writable) {
setUserDefinedWritability(index);
} else {
clearUserDefinedWritability(index);
}
}
private void setUserDefinedWritability(int index) {
final int mask = ~writabilityMask(index);
for (;;) {
final int oldValue = unwritable;
final int newValue = oldValue & mask;
if (UNWRITABLE_UPDATER.compareAndSet(this, oldValue, newValue)) {
if (oldValue != 0 && newValue == 0) {
fireChannelWritabilityChanged(true);
}
break;
}
}
}
private void clearUserDefinedWritability(int index) {
final int mask = writabilityMask(index);
for (;;) {
final int oldValue = unwritable;
final int newValue = oldValue | mask;
if (UNWRITABLE_UPDATER.compareAndSet(this, oldValue, newValue)) {
if (oldValue == 0 && newValue != 0) {
fireChannelWritabilityChanged(true);
}
break;
}
}
}
private static int writabilityMask(int index) {
if (index < 1 || index > 31) {
throw new IllegalArgumentException("index: " + index + " (expected: 1~31)");
}
return 1 << index;
}
private void setWritable(boolean invokeLater) {
for (;;) {
final int oldValue = unwritable;
final int newValue = oldValue & ~1;
if (UNWRITABLE_UPDATER.compareAndSet(this, oldValue, newValue)) {
if (oldValue != 0 && newValue == 0) {
fireChannelWritabilityChanged(invokeLater);
}
break;
}
}
}
private void setUnwritable(boolean invokeLater) {
for (;;) {
final int oldValue = unwritable;
final int newValue = oldValue | 1;
if (UNWRITABLE_UPDATER.compareAndSet(this, oldValue, newValue)) {
if (oldValue == 0 && newValue != 0) {
fireChannelWritabilityChanged(invokeLater);
}
break;
}
}
}
private void fireChannelWritabilityChanged(boolean invokeLater) {
final ChannelPipeline pipeline = channel.pipeline();
if (invokeLater) {
Runnable task = fireChannelWritabilityChangedTask;
if (task == null) {
fireChannelWritabilityChangedTask = task = new Runnable() {
@Override
public void run() {
pipeline.fireChannelWritabilityChanged();
}
};
}
channel.eventLoop().execute(task);
} else {
pipeline.fireChannelWritabilityChanged();
}
}
/**
* Returns the number of flushed messages in this {@link ChannelOutboundBuffer}.
*/
public int size() {
return flushed;
}
/**
* Returns {@code true} if there are flushed messages in this {@link ChannelOutboundBuffer} or {@code false}
* otherwise.
*/
public boolean isEmpty() {
return flushed == 0;
}
void failFlushed(Throwable cause) {
// Make sure that this method does not reenter. A listener added to the current promise can be notified by the
// current thread in the tryFailure() call of the loop below, and the listener can trigger another fail() call
// indirectly (usually by closing the channel.)
//
// See https://github.com/netty/netty/issues/1501
if (inFail) {
return;
}
try {
inFail = true;
for (;;) {
if (!remove(cause)) {
break;
}
}
} finally {
inFail = false;
}
}
void close(final ClosedChannelException cause) {
if (inFail) {
channel.eventLoop().execute(new Runnable() {
@Override
public void run() {
close(cause);
}
});
return;
}
inFail = true;
if (channel.isOpen()) {
throw new IllegalStateException("close() must be invoked after the channel is closed.");
}
if (!isEmpty()) {
throw new IllegalStateException("close() must be invoked after all flushed writes are handled.");
}
// Release all unflushed messages.
try {
Entry e = unflushedEntry;
while (e != null) {
// Just decrease; do not trigger any events via decrementPendingOutboundBytes()
int size = e.pendingSize;
TOTAL_PENDING_SIZE_UPDATER.addAndGet(this, -size);
if (!e.cancelled) {
ReferenceCountUtil.safeRelease(e.msg);
safeFail(e.promise, cause);
}
e = e.recycleAndGetNext();
}
} finally {
inFail = false;
}
}
private static void safeSuccess(ChannelPromise promise) {
if (!(promise instanceof VoidChannelPromise) && !promise.trySuccess()) {
logger.warn("Failed to mark a promise as success because it is done already: {}", promise);
}
}
private static void safeFail(ChannelPromise promise, Throwable cause) {
if (!(promise instanceof VoidChannelPromise) && !promise.tryFailure(cause)) {
logger.warn("Failed to mark a promise as failure because it's done already: {}", promise, cause);
}
}
@Deprecated
public void recycle() {
// NOOP
}
public long totalPendingWriteBytes() {
return totalPendingSize;
}
/**
* Call {@link MessageProcessor#processMessage(Object)} for each flushed message
* in this {@link ChannelOutboundBuffer} until {@link MessageProcessor#processMessage(Object)}
* returns {@code false} or there are no more flushed messages to process.
*/
public void forEachFlushedMessage(MessageProcessor processor) throws Exception {
if (processor == null) {
throw new NullPointerException("processor");
}
Entry entry = flushedEntry;
if (entry == null) {
return;
}
do {
if (!entry.cancelled) {
if (!processor.processMessage(entry.msg)) {
return;
}
}
entry = entry.next;
} while (isFlushedEntry(entry));
}
private boolean isFlushedEntry(Entry e) {
return e != null && e != unflushedEntry;
}
public interface MessageProcessor {
/**
* Will be called for each flushed message until it either there are no more flushed messages or this
* method returns {@code false}.
*/
boolean processMessage(Object msg) throws Exception;
}
static final class Entry {
private static final Recycler RECYCLER = new Recycler() {
@Override
protected Entry newObject(Handle handle) {
return new Entry(handle);
}
};
private final Handle handle;
Entry next;
Object msg;
ByteBuffer[] bufs;
ByteBuffer buf;
ChannelPromise promise;
long progress;
long total;
int pendingSize;
int count = -1;
boolean cancelled;
private Entry(Handle handle) {
this.handle = handle;
}
static Entry newInstance(Object msg, int size, long total, ChannelPromise promise) {
Entry entry = RECYCLER.get();
entry.msg = msg;
entry.pendingSize = size;
entry.total = total;
entry.promise = promise;
return entry;
}
int cancel() {
if (!cancelled) {
cancelled = true;
int pSize = pendingSize;
// release message and replace with an empty buffer
ReferenceCountUtil.safeRelease(msg);
msg = Unpooled.EMPTY_BUFFER;
pendingSize = 0;
total = 0;
progress = 0;
bufs = null;
buf = null;
return pSize;
}
return 0;
}
void recycle() {
next = null;
bufs = null;
buf = null;
msg = null;
promise = null;
progress = 0;
total = 0;
pendingSize = 0;
count = -1;
cancelled = false;
RECYCLER.recycle(this, handle);
}
Entry recycleAndGetNext() {
Entry next = this.next;
recycle();
return next;
}
}
}