org.xnio.channels.TranslatingSuspendableChannel Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source
* Copyright 2011, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.xnio.channels;
import static java.lang.Thread.currentThread;
import static java.util.Arrays.copyOf;
import static java.util.concurrent.locks.LockSupport.park;
import static java.util.concurrent.locks.LockSupport.parkNanos;
import static java.util.concurrent.locks.LockSupport.unpark;
import java.io.IOException;
import java.nio.channels.Channel;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
import org.xnio.ChannelListener;
import org.xnio.ChannelListeners;
import org.xnio.IoUtils;
import org.xnio.Option;
import org.xnio.XnioExecutor;
import org.xnio.XnioWorker;
import static org.xnio.Bits.*;
/**
* An abstract wrapped channel.
*
* @param the channel type implemented by this class
* @param the channel type being wrapped by this class
*
* @author David M. Lloyd
*/
@SuppressWarnings("unused")
public abstract class TranslatingSuspendableChannel implements SuspendableChannel, WrappedChannel {
/**
* The wrapped channel.
*/
protected final W channel;
private final ChannelListener.SimpleSetter readSetter = new ChannelListener.SimpleSetter();
private final ChannelListener.SimpleSetter writeSetter = new ChannelListener.SimpleSetter();
private final ChannelListener.SimpleSetter closeSetter = new ChannelListener.SimpleSetter();
private volatile int state;
private volatile Thread[] readWaiters = NOT_WAITING;
private volatile Thread[] writeWaiters = NOT_WAITING;
private static final Thread[] NOT_WAITING = new Thread[0];
private static final AtomicIntegerFieldUpdater stateUpdater = AtomicIntegerFieldUpdater.newUpdater(TranslatingSuspendableChannel.class, "state");
private static final AtomicReferenceFieldUpdater readWaitersUpdater = AtomicReferenceFieldUpdater.newUpdater(TranslatingSuspendableChannel.class, Thread[].class, "readWaiters");
private static final AtomicReferenceFieldUpdater writeWaitersUpdater = AtomicReferenceFieldUpdater.newUpdater(TranslatingSuspendableChannel.class, Thread[].class, "writeWaiters");
// read-side
private static final int READ_REQUESTED = 1 << 0x00; // user wants to be notified on read
private static final int READ_REQUIRES_WRITE = 1 << 0x01; // channel cannot be read due to pending write
private static final int READ_READY = 1 << 0x02; // channel is always ready to be read
private static final int READ_SHUT_DOWN = 1 << 0x03; // user shut down reads
private static final int READ_REQUIRES_EXT = intBitMask(0x0B, 0x0F); // channel cannot be read until external event completes, up to 32 events
private static final int READ_SINGLE_EXT = 1 << 0x0B; // one external event count value
private static final int READ_FLAGS = intBitMask(0x00, 0x0F);
// write-side
private static final int WRITE_REQUESTED = 1 << 0x10;
private static final int WRITE_REQUIRES_READ = 1 << 0x11;
private static final int WRITE_READY = 1 << 0x12;
private static final int WRITE_SHUT_DOWN = 1 << 0x13; // user requested shut down of writes
private static final int WRITE_COMPLETE = 1 << 0x14; // flush acknowledged full write shutdown
private static final int WRITE_REQUIRES_EXT = intBitMask(0x1B, 0x1F); // up to 32 events
private static final int WRITE_SINGLE_EXT = 1 << 0x1B;
private static final int WRITE_FLAGS = intBitMask(0x10, 0x1F);
private final ChannelListener readListener = new ChannelListener() {
public void handleEvent(final Channel channel) {
handleReadable();
}
public String toString() {
return "Read listener for " + TranslatingSuspendableChannel.this;
}
};
private final ChannelListener writeListener = new ChannelListener() {
public void handleEvent(final Channel channel) {
handleWritable();
}
public String toString() {
return "Write listener for " + TranslatingSuspendableChannel.this;
}
};
private final ChannelListener closeListener = new ChannelListener() {
public void handleEvent(final Channel channel) {
IoUtils.safeClose(TranslatingSuspendableChannel.this);
}
public String toString() {
return "Close listener for " + TranslatingSuspendableChannel.this;
}
};
/**
* Construct a new instance.
*
* @param channel the channel being wrapped
*/
protected TranslatingSuspendableChannel(final W channel) {
if (channel == null) {
throw new IllegalArgumentException("channel is null");
}
this.channel = channel;
channel.getReadSetter().set(readListener);
channel.getWriteSetter().set(writeListener);
channel.getCloseSetter().set(closeListener);
}
/**
* Called when the underlying channel is readable.
*/
protected void handleReadable() {
int oldState;
oldState = clearFlags(WRITE_REQUIRES_READ);
if (allAreSet(oldState, WRITE_REQUIRES_READ)) {
unparkWriteWaiters();
if (allAreSet(oldState, WRITE_REQUESTED)) {
channel.wakeupWrites();
}
}
if (allAreClear(oldState, READ_READY) && anyAreSet(oldState, READ_REQUIRES_WRITE | READ_REQUIRES_EXT)) {
channel.suspendReads();
oldState = state;
if (anyAreSet(oldState, READ_READY) || allAreClear(oldState, READ_REQUIRES_WRITE | READ_REQUIRES_EXT)) {
// undo
channel.resumeReads();
} else {
return;
}
}
do {
if (anyAreSet(oldState, READ_SHUT_DOWN)) {
channel.suspendReads();
return;
}
if (allAreClear(oldState, READ_REQUESTED)) {
channel.suspendReads();
oldState = state;
if (allAreSet(oldState, READ_REQUESTED)) {
// undo
channel.resumeReads();
} else {
return;
}
}
unparkReadWaiters();
final ChannelListener listener = readSetter.get();
if (listener == null) {
// damage control
oldState = clearFlag(READ_REQUESTED | WRITE_REQUIRES_READ) & ~READ_REQUESTED;
} else {
ChannelListeners.invokeChannelListener(thisTyped(), listener);
oldState = clearFlags(WRITE_REQUIRES_READ);
}
if (allAreSet(oldState, WRITE_REQUIRES_READ)) {
unparkWriteWaiters();
// race is OK
channel.wakeupWrites();
}
} while (allAreSet(oldState, READ_READY));
}
/**
* Called when the underlying channel is writable.
*/
protected void handleWritable() {
int oldState;
oldState = clearFlags(READ_REQUIRES_WRITE);
if (allAreSet(oldState, READ_REQUIRES_WRITE)) {
unparkReadWaiters();
if (allAreSet(oldState, READ_REQUESTED)) {
channel.wakeupReads();
}
}
if (allAreClear(oldState, WRITE_READY) && anyAreSet(oldState, WRITE_REQUIRES_READ | WRITE_REQUIRES_EXT)) {
channel.suspendWrites();
oldState = state;
if (anyAreSet(oldState, WRITE_READY) || allAreClear(oldState, WRITE_REQUIRES_READ | WRITE_REQUIRES_EXT)) {
// undo
channel.resumeWrites();
} else {
return;
}
}
do {
if (anyAreSet(oldState, WRITE_COMPLETE)) {
channel.suspendWrites();
return;
}
if (allAreClear(oldState, WRITE_REQUESTED)) {
channel.suspendWrites();
oldState = state;
if (allAreSet(oldState, WRITE_REQUESTED)) {
// undo
channel.resumeWrites();
} else {
return;
}
}
unparkWriteWaiters();
final ChannelListener listener = writeSetter.get();
if (listener == null) {
// damage control
oldState = clearFlags(WRITE_REQUESTED | READ_REQUIRES_WRITE) & ~WRITE_REQUESTED;
} else {
ChannelListeners.invokeChannelListener(thisTyped(), listener);
oldState = clearFlags(READ_REQUIRES_WRITE);
}
if (allAreSet(oldState, READ_REQUIRES_WRITE)) {
unparkReadWaiters();
// race is OK
channel.wakeupReads();
}
} while (allAreSet(oldState, WRITE_READY));
}
/**
* Called when the underlying channel is closed.
*
*/
protected void handleClosed() {
ChannelListeners.invokeChannelListener(thisTyped(), closeSetter.get());
}
// --- read ---
/**
* Indicate that the channel is definitely immediately readable, regardless of the underlying channel state.
*/
protected void setReadReady() {
int oldState = setFlags(READ_READY);
if (allAreSet(oldState, READ_READY)) {
// idempotent
return;
}
if (allAreSet(oldState, READ_REQUESTED) && anyAreSet(oldState, READ_REQUIRES_EXT | READ_REQUIRES_WRITE)) {
// wakeup is required to proceed
channel.wakeupReads();
}
}
/**
* Indicate that the channel is no longer definitely immediately readable.
*/
protected void clearReadReady() {
int oldState = clearFlags(READ_READY);
if (allAreClear(oldState, READ_READY)) {
// idempotent
return;
}
if (!allAreClear(oldState, READ_REQUESTED) && !anyAreSet(oldState, READ_REQUIRES_EXT | READ_REQUIRES_WRITE)) {
// we can read again when the underlying channel is ready
channel.resumeReads();
}
}
/**
* Indicate that the channel will not be readable until the write handler is called.
*/
protected void setReadRequiresWrite() {
int oldState = setFlags(READ_REQUIRES_WRITE);
if (allAreSet(oldState, READ_REQUIRES_WRITE)) {
// not the first caller
return;
}
if (allAreClear(oldState, READ_READY | READ_REQUIRES_EXT)) {
// read cannot proceed until write does
channel.resumeWrites();
}
}
/**
* Indicate if the channel is not readable until the write handler is called.
*/
protected boolean readRequiresWrite() {
return allAreSet(state, READ_REQUIRES_WRITE);
}
/**
* Indicate that the channel no longer requires writability for reads to proceed.
*/
protected void clearReadRequiresWrite() {
int oldState = clearFlags(READ_REQUIRES_WRITE);
if (allAreClear(oldState, READ_REQUIRES_WRITE)) {
// idempotent
return;
}
if (allAreClear(oldState, READ_REQUIRES_EXT) && allAreSet(oldState, READ_REQUESTED)) {
if (allAreSet(oldState, READ_READY)) {
channel.wakeupReads();
} else {
channel.resumeReads();
}
}
}
/**
* Indicate that read requires an external task to complete.
*
* @return {@code true} if the flag was set, {@code false} if too many tasks are already outstanding
*/
protected boolean tryAddReadRequiresExternal() {
int oldState = addFlag(READ_REQUIRES_EXT, READ_SINGLE_EXT);
return (oldState & READ_REQUIRES_EXT) != READ_REQUIRES_EXT;
}
/**
* Indicate that one external read task was completed. This method should be called once for every time
* that {@link #tryAddReadRequiresExternal()} returned {@code true}.
*/
protected void removeReadRequiresExternal() {
clearFlag(READ_SINGLE_EXT);
}
/**
* Set the channel read shut down flag.
*
* @return {@code true} if the channel has fully closed due to this call, {@code false} otherwise
*/
protected boolean setReadShutDown() {
return (setFlags(READ_SHUT_DOWN) & (READ_SHUT_DOWN | WRITE_SHUT_DOWN)) == WRITE_SHUT_DOWN;
}
// --- write ---
/**
* Indicate that the channel is definitely immediately writable, regardless of the underlying channel state.
*/
protected void setWriteReady() {
int oldState = setFlags(WRITE_READY);
if (allAreSet(oldState, WRITE_READY)) {
// idempotent
return;
}
if (allAreSet(oldState, WRITE_REQUESTED) && anyAreSet(oldState, WRITE_REQUIRES_EXT | WRITE_REQUIRES_READ)) {
// wakeup is required to proceed
channel.wakeupWrites();
}
}
/**
* Indicate that the channel is no longer definitely immediately writable.
*/
protected void clearWriteReady() {
int oldState = clearFlags(WRITE_READY);
if (allAreClear(oldState, WRITE_READY)) {
// idempotent
return;
}
if (!allAreClear(oldState, WRITE_REQUESTED) && ! anyAreSet(oldState, WRITE_REQUIRES_EXT | WRITE_REQUIRES_READ)) {
// we can write again when the underlying channel is ready
channel.resumeWrites();
}
}
/**
* Indicate that the channel will not be writable until the read handler is called.
*/
protected void setWriteRequiresRead() {
int oldState = setFlags(WRITE_REQUIRES_READ);
if (allAreSet(oldState, WRITE_REQUIRES_READ)) {
// not the first caller
return;
}
if (allAreClear(oldState, WRITE_READY | WRITE_REQUIRES_EXT)) {
// write cannot proceed until read does
channel.resumeReads();
}
}
/**
* Indicate if the channel is not writable until the read handler is called.
*/
protected boolean writeRequiresRead() {
return allAreSet(state, WRITE_REQUIRES_READ);
}
/**
* Indicate that the channel no longer requires writability for writes to proceed.
*/
protected void clearWriteRequiresRead() {
int oldState = clearFlags(WRITE_REQUIRES_READ);
if (allAreClear(oldState, WRITE_REQUIRES_READ)) {
// idempotent
return;
}
if (allAreClear(oldState, WRITE_REQUIRES_EXT) && allAreSet(oldState, WRITE_REQUESTED)) {
if (allAreSet(oldState, WRITE_READY)) {
channel.wakeupWrites();
} else {
channel.resumeWrites();
}
}
}
/**
* Indicate that write requires an external task to complete.
*
* @return {@code true} if the flag was set, {@code false} if too many tasks are already outstanding
*/
protected boolean tryAddWriteRequiresExternal() {
int oldState = addFlag(WRITE_REQUIRES_EXT, WRITE_SINGLE_EXT);
return (oldState & WRITE_REQUIRES_EXT) != WRITE_REQUIRES_EXT;
}
/**
* Indicate that one external write task was completed. This method should be called once for every time
* that {@link #tryAddWriteRequiresExternal()} returned {@code true}.
*/
protected void removeWriteRequiresExternal() {
clearFlag(WRITE_SINGLE_EXT);
}
/**
* Set the channel write shut down flag.
*
* @return {@code true} if the channel has fully closed due to this call, {@code false} otherwise
*/
protected boolean setWriteShutDown() {
return (setFlags(WRITE_SHUT_DOWN) & (WRITE_SHUT_DOWN | READ_SHUT_DOWN)) == READ_SHUT_DOWN;
}
// --- read & write ---
/**
* Set both the channel read and write shut down flags.
*
* @return {@code true} if the channel has fully closed (for the first time) due to this call, {@code false} otherwise
*/
protected boolean setClosed() {
return (setFlags(READ_SHUT_DOWN | WRITE_SHUT_DOWN) & (READ_SHUT_DOWN | WRITE_SHUT_DOWN)) != (READ_SHUT_DOWN | WRITE_SHUT_DOWN);
}
/**
* Get this channel, cast to the implemented channel type.
*
* @return {@code this}
*/
@SuppressWarnings("unchecked")
protected final C thisTyped() {
return (C) this;
}
/** {@inheritDoc} */
public ChannelListener.Setter getCloseSetter() {
return closeSetter;
}
/** {@inheritDoc} */
public ChannelListener.Setter getReadSetter() {
return readSetter;
}
/** {@inheritDoc} */
public ChannelListener.Setter getWriteSetter() {
return writeSetter;
}
/** {@inheritDoc} */
public void suspendReads() {
clearFlags(READ_REQUESTED);
// let the read/write handler actually suspend, to avoid awkward race conditions
}
/** {@inheritDoc} */
public void resumeReads() {
final int oldState = setFlags(READ_REQUESTED);
if (anyAreSet(oldState, READ_REQUESTED | READ_SHUT_DOWN)) {
// idempotent or shut down, either way
return;
}
if (allAreSet(oldState, READ_READY)) {
// reads are known to be ready so trigger listener right away
channel.wakeupReads();
return;
}
if (allAreClear(oldState, READ_REQUIRES_EXT)) {
if (allAreSet(oldState, READ_REQUIRES_WRITE)) {
channel.resumeWrites();
} else {
channel.resumeReads();
}
}
}
public boolean isReadResumed() {
return allAreSet(state, READ_REQUESTED);
}
/** {@inheritDoc} */
public void wakeupReads() {
final int oldState = setFlags(READ_REQUESTED);
if (anyAreSet(oldState, READ_SHUT_DOWN)) {
return;
}
channel.wakeupReads();
}
/** {@inheritDoc} */
public void suspendWrites() {
clearFlags(WRITE_REQUESTED);
// let the read/write handler actually suspend, to avoid awkward race conditions
}
/** {@inheritDoc} */
public void resumeWrites() {
final int oldState = setFlags(WRITE_REQUESTED);
if (anyAreSet(oldState, WRITE_REQUESTED | WRITE_COMPLETE)) {
// idempotent or shut down, either way
return;
}
if (allAreSet(oldState, WRITE_READY)) {
// reads are known to be ready so trigger listener right away
channel.wakeupWrites();
return;
}
if (allAreClear(oldState, WRITE_REQUIRES_EXT)) {
if (allAreSet(oldState, WRITE_REQUIRES_READ)) {
channel.resumeReads();
} else {
channel.resumeWrites();
}
}
}
public boolean isWriteResumed() {
return allAreSet(state, WRITE_REQUESTED);
}
/** {@inheritDoc} */
public void wakeupWrites() {
final int oldState = setFlags(WRITE_REQUESTED);
if (anyAreSet(oldState, WRITE_COMPLETE)) {
return;
}
channel.wakeupWrites();
}
/** {@inheritDoc} */
public boolean supportsOption(final Option option) {
return channel.supportsOption(option);
}
/** {@inheritDoc} */
public T getOption(final Option option) throws IOException {
return channel.getOption(option);
}
/** {@inheritDoc} */
public T setOption(final Option option, final T value) throws IllegalArgumentException, IOException {
return channel.setOption(option, value);
}
/**
* Perform channel flush. To change the action taken to flush, subclasses should override {@link #flushAction(boolean)}.
*
* @return {@code true} if the flush completed, or {@code false} if the operation would block
* @throws IOException if an error occurs
*/
public final boolean flush() throws IOException {
int oldState, newState;
oldState = stateUpdater.get(this);
if (allAreSet(oldState, WRITE_COMPLETE)) {
return channel.flush();
}
final boolean shutDown = allAreSet(oldState, WRITE_SHUT_DOWN);
if (! flushAction(shutDown)) {
return false;
}
if (! shutDown) {
return true;
}
newState = oldState | WRITE_COMPLETE;
while (! stateUpdater.compareAndSet(this, oldState, newState)) {
oldState = stateUpdater.get(this);
if (allAreSet(oldState, WRITE_COMPLETE)) {
return channel.flush();
}
newState = oldState | WRITE_COMPLETE;
}
final boolean readShutDown = allAreSet(oldState, READ_SHUT_DOWN);
try {
shutdownWritesComplete(readShutDown);
} finally {
if (readShutDown) ChannelListeners.invokeChannelListener(thisTyped(), closeSetter.get());
}
return channel.flush();
}
/**
* The action to perform when the channel is flushed. By default, this method delegates to the underlying channel.
* If the {@code shutDown} parameter is set, and this method returns {@code true}, the underlying channel will be
* shut down and this method will never be called again (future calls to {@link #flush()} will flush the underlying
* channel until it returns {@code true}).
*
* @param shutDown {@code true} if the channel's write side has been shut down, {@code false} otherwise
* @return {@code true} if the flush succeeded, {@code false} if it would block
* @throws IOException if an error occurs
*/
protected boolean flushAction(final boolean shutDown) throws IOException {
return channel.flush();
}
/**
* Notification that the channel has successfully flushed after having shut down writes. The underlying
* channel may not yet be fully flushed at this time.
*
* @param readShutDown {@code true} if the read side was already shut down, {@code false} otherwise
* @throws IOException if an error occurs
*/
protected void shutdownWritesComplete(final boolean readShutDown) throws IOException {
}
/**
* Perform the read shutdown action if it hasn't been performed already.
*
* @throws IOException if an I/O error occurs
*/
public void shutdownReads() throws IOException {
int old = setFlags(READ_SHUT_DOWN);
if (allAreClear(old, READ_SHUT_DOWN)) {
final boolean writeComplete = allAreSet(old, WRITE_COMPLETE);
try {
shutdownReadsAction(writeComplete);
} finally {
if (writeComplete) {
ChannelListeners.invokeChannelListener(thisTyped(), closeSetter.get());
}
}
}
}
/**
* The action to perform when reads are shut down. By default, this method delegates to the underlying channel.
*
* @throws IOException if an error occurs
* @param writeComplete
*/
protected void shutdownReadsAction(final boolean writeComplete) throws IOException {
channel.shutdownReads();
}
/**
* Determine whether the channel is shut down for reads.
*
* @return whether the channel is shut down for reads
*/
protected boolean isReadShutDown() {
return allAreSet(state, READ_SHUT_DOWN);
}
/**
* Base implementation method which simply delegates the shutdown request to the delegate channel. Subclasses may
* override this method and call up to this method as appropriate.
*
* @return {@code true} if the channel was shut down, or {@code false} if the operation would block
* @throws IOException if an I/O error occurs
*/
public void shutdownWrites() throws IOException {
int old = setFlags(WRITE_SHUT_DOWN);
if (allAreClear(old, WRITE_SHUT_DOWN)) {
shutdownWritesAction();
}
}
/**
* The action to perform when writes are requested to be shut down. By default, this method delegates to the
* underlying channel.
*
* @throws IOException if an error occurs
*/
protected void shutdownWritesAction() throws IOException {
channel.shutdownWrites();
}
/**
* Determine whether the channel is shut down for writes.
*
* @return whether the channel is shut down for writes
*/
protected boolean isWriteShutDown() {
return allAreSet(state, WRITE_SHUT_DOWN);
}
protected boolean isWriteComplete() {
return allAreSet(state, WRITE_COMPLETE);
}
/** {@inheritDoc} */
public void awaitReadable() throws IOException {
int oldState = state;
if (anyAreSet(oldState, READ_READY | READ_SHUT_DOWN)) {
return;
}
if (addReadWaiter()) {
if (allAreSet(oldState, READ_REQUIRES_WRITE)) {
channel.resumeWrites();
} else {
channel.resumeReads();
}
park(this);
}
return;
}
/** {@inheritDoc} */
public void awaitReadable(final long time, final TimeUnit timeUnit) throws IOException {
int oldState = state;
if (anyAreSet(oldState, READ_READY | READ_SHUT_DOWN)) {
return;
}
if (addReadWaiter()) {
if (allAreSet(oldState, READ_REQUIRES_WRITE)) {
channel.resumeWrites();
} else {
channel.resumeReads();
}
parkNanos(this, timeUnit.toNanos(time));
}
return;
}
public XnioExecutor getReadThread() {
return channel.getReadThread();
}
/** {@inheritDoc} */
public void awaitWritable() throws IOException {
int oldState = state;
if (anyAreSet(oldState, WRITE_READY | WRITE_SHUT_DOWN)) {
return;
}
if (addWriteWaiter()) {
if (allAreSet(oldState, WRITE_REQUIRES_READ)) {
channel.resumeReads();
} else {
channel.resumeWrites();
}
park(this);
}
return;
}
/** {@inheritDoc} */
public void awaitWritable(final long time, final TimeUnit timeUnit) throws IOException {
int oldState = state;
if (anyAreSet(oldState, WRITE_READY | WRITE_SHUT_DOWN)) {
return;
}
if (addWriteWaiter()) {
if (allAreSet(oldState, WRITE_REQUIRES_READ)) {
channel.resumeReads();
} else {
channel.resumeWrites();
}
parkNanos(this, timeUnit.toNanos(time));
}
return;
}
public XnioExecutor getWriteThread() {
return channel.getWriteThread();
}
/**
* Close this channel. This method is idempotent.
*
* @throws IOException if an I/O error occurs
*/
public void close() throws IOException {
int old = setFlags(READ_SHUT_DOWN | WRITE_SHUT_DOWN | WRITE_COMPLETE);
final boolean readShutDown = allAreSet(old, READ_SHUT_DOWN), writeShutDown = allAreSet(old, WRITE_COMPLETE);
if (! (readShutDown && writeShutDown)) try {
closeAction(readShutDown, writeShutDown);
} finally {
ChannelListeners.invokeChannelListener(thisTyped(), closeSetter.get());
}
}
/**
* The action to perform when the channel is closed via the {@link #close()} method. By default, the underlying
* channel is closed.
*
* @param readShutDown if reads were previously shut down
* @param writeShutDown if writes were previously shut down
* @throws IOException if an error occurs
*/
protected void closeAction(final boolean readShutDown, final boolean writeShutDown) throws IOException {
channel.close();
}
/** {@inheritDoc} */
public boolean isOpen() {
return ! allAreSet(state, READ_SHUT_DOWN | WRITE_COMPLETE);
}
/** {@inheritDoc} */
public W getChannel() {
return channel;
}
/** {@inheritDoc} */
public XnioWorker getWorker() {
return channel.getWorker();
}
/** {@inheritDoc} */
public String toString() {
return getClass().getName() + " around " + channel;
}
// state operations
private int setFlags(int flags) {
int oldState;
do {
oldState = state;
if ((oldState & flags) == flags) {
return oldState;
}
} while (! stateUpdater.compareAndSet(this, oldState, oldState | flags));
return oldState;
}
private int clearFlags(int flags) {
int oldState;
do {
oldState = state;
if ((oldState & flags) == 0) {
return oldState;
}
} while (! stateUpdater.compareAndSet(this, oldState, oldState & ~flags));
return oldState;
}
private int addFlag(final int mask, final int count) {
int oldState;
do {
oldState = state;
if ((oldState & mask) == mask) {
return oldState;
}
} while (! stateUpdater.compareAndSet(this, oldState, oldState + count));
return oldState;
}
private int clearFlag(final int count) {
return stateUpdater.getAndAdd(this, -count);
}
private boolean addReadWaiter() {
Thread[] oldWaiters, newWaiters;
do {
oldWaiters = readWaiters;
if (oldWaiters == NOT_WAITING) {
return false;
} else if (oldWaiters == null) {
newWaiters = new Thread[] { currentThread() };
} else {
final int oldLength = oldWaiters.length;
for (int i = 0; i < oldLength; i++) {
if (oldWaiters[i] == currentThread()) {
return true;
}
}
newWaiters = copyOf(oldWaiters, oldLength + 1);
newWaiters[oldLength] = currentThread();
}
} while (! readWaitersUpdater.compareAndSet(this, oldWaiters, newWaiters));
return true;
}
private boolean addWriteWaiter() {
Thread[] oldWaiters, newWaiters;
do {
oldWaiters = writeWaiters;
if (oldWaiters == NOT_WAITING) {
return false;
} else if (oldWaiters == null) {
newWaiters = new Thread[] { currentThread() };
} else {
final int oldLength = oldWaiters.length;
for (int i = 0; i < oldLength; i++) {
if (oldWaiters[i] == currentThread()) {
return true;
}
}
newWaiters = copyOf(oldWaiters, oldLength + 1);
newWaiters[oldLength] = currentThread();
}
} while (! writeWaitersUpdater.compareAndSet(this, oldWaiters, newWaiters));
return true;
}
private void unparkReadWaiters() {
final Thread[] waiters = readWaitersUpdater.getAndSet(this, NOT_WAITING);
for (Thread waiter : waiters) {
unpark(waiter);
}
}
private void unparkWriteWaiters() {
final Thread[] waiters = writeWaitersUpdater.getAndSet(this, NOT_WAITING);
for (Thread waiter : waiters) {
unpark(waiter);
}
}
}
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