/*
* Copyright (c) 2014 AsyncHttpClient Project. All rights reserved.
*
* This program is licensed to you under the Apache License Version 2.0,
* and you may not use this file except in compliance with the Apache License Version 2.0.
* You may obtain a copy of the Apache License Version 2.0 at
* http://www.apache.org/licenses/LICENSE-2.0.
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the Apache License Version 2.0 is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the Apache License Version 2.0 for the specific language governing permissions and limitations there under.
*/
package org.asynchttpclient.netty.channel;
import static org.asynchttpclient.util.Assertions.assertNotNull;
import static org.asynchttpclient.util.DateUtils.unpreciseMillisTime;
import io.netty.channel.Channel;
import io.netty.channel.ChannelId;
import io.netty.util.Timeout;
import io.netty.util.Timer;
import io.netty.util.TimerTask;
import java.net.InetSocketAddress;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedDeque;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import org.asynchttpclient.AsyncHttpClientConfig;
import org.asynchttpclient.channel.ChannelPool;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A simple implementation of {@link ChannelPool} based on a {@link java.util.concurrent.ConcurrentHashMap}
*/
public final class DefaultChannelPool implements ChannelPool {
private static final Logger LOGGER = LoggerFactory.getLogger(DefaultChannelPool.class);
private final ConcurrentHashMap<Object, ConcurrentLinkedDeque<IdleChannel>> partitions = new ConcurrentHashMap<>();
private final ConcurrentHashMap<ChannelId, ChannelCreation> channelId2Creation;
private final AtomicBoolean isClosed = new AtomicBoolean(false);
private final Timer nettyTimer;
private final int connectionTtl;
private final boolean connectionTtlEnabled;
private final int maxIdleTime;
private final boolean maxIdleTimeEnabled;
private final long cleanerPeriod;
private final PoolLeaseStrategy poolLeaseStrategy;
public DefaultChannelPool(AsyncHttpClientConfig config, Timer hashedWheelTimer) {
this(config.getPooledConnectionIdleTimeout(),//
config.getConnectionTtl(),//
hashedWheelTimer,//
config.getConnectionPoolCleanerPeriod());
}
public DefaultChannelPool(int maxIdleTime,//
int connectionTtl,//
Timer nettyTimer,//
int cleanerPeriod) {
this(maxIdleTime,//
connectionTtl,//
PoolLeaseStrategy.LIFO,//
nettyTimer,//
cleanerPeriod);
}
public DefaultChannelPool(int maxIdleTime,//
int connectionTtl,//
PoolLeaseStrategy poolLeaseStrategy,//
Timer nettyTimer,//
int cleanerPeriod) {
this.maxIdleTime = maxIdleTime;
this.connectionTtl = connectionTtl;
connectionTtlEnabled = connectionTtl > 0;
channelId2Creation = connectionTtlEnabled ? new ConcurrentHashMap<>() : null;
this.nettyTimer = nettyTimer;
maxIdleTimeEnabled = maxIdleTime > 0;
this.poolLeaseStrategy = poolLeaseStrategy;
this.cleanerPeriod = Math.min(cleanerPeriod, Math.min(connectionTtlEnabled ? connectionTtl : Integer.MAX_VALUE, maxIdleTimeEnabled ? maxIdleTime : Integer.MAX_VALUE));
if (connectionTtlEnabled || maxIdleTimeEnabled)
scheduleNewIdleChannelDetector(new IdleChannelDetector());
}
private void scheduleNewIdleChannelDetector(TimerTask task) {
nettyTimer.newTimeout(task, cleanerPeriod, TimeUnit.MILLISECONDS);
}
private static final class ChannelCreation {
final long creationTime;
final Object partitionKey;
ChannelCreation(long creationTime, Object partitionKey) {
this.creationTime = creationTime;
this.partitionKey = partitionKey;
}
}
private static final class IdleChannel {
final Channel channel;
final long start;
final AtomicBoolean owned = new AtomicBoolean(false);
IdleChannel(Channel channel, long start) {
this.channel = assertNotNull(channel, "channel");
this.start = start;
}
public boolean takeOwnership() {
return owned.compareAndSet(false, true);
}
public Channel getChannel() {
return channel;
}
@Override
// only depends on channel
public boolean equals(Object o) {
return this == o || (o instanceof IdleChannel && channel.equals(IdleChannel.class.cast(o).channel));
}
@Override
public int hashCode() {
return channel.hashCode();
}
}
private boolean isTtlExpired(Channel channel, long now) {
if (!connectionTtlEnabled)
return false;
ChannelCreation creation = channelId2Creation.get(channel.id());
return creation != null && now - creation.creationTime >= connectionTtl;
}
private boolean isRemotelyClosed(Channel channel) {
return !channel.isActive();
}
private final class IdleChannelDetector implements TimerTask {
private boolean isIdleTimeoutExpired(IdleChannel idleChannel, long now) {
return maxIdleTimeEnabled && now - idleChannel.start >= maxIdleTime;
}
private List<IdleChannel> expiredChannels(ConcurrentLinkedDeque<IdleChannel> partition, long now) {
// lazy create
List<IdleChannel> idleTimeoutChannels = null;
for (IdleChannel idleChannel : partition) {
boolean isIdleTimeoutExpired = isIdleTimeoutExpired(idleChannel, now);
boolean isRemotelyClosed = isRemotelyClosed(idleChannel.channel);
boolean isTtlExpired = isTtlExpired(idleChannel.channel, now);
if (isIdleTimeoutExpired || isRemotelyClosed || isTtlExpired) {
LOGGER.debug("Adding Candidate expired Channel {} isIdleTimeoutExpired={} isRemotelyClosed={} isTtlExpired={}", idleChannel.channel, isIdleTimeoutExpired, isRemotelyClosed, isTtlExpired);
if (idleTimeoutChannels == null)
idleTimeoutChannels = new ArrayList<>(1);
idleTimeoutChannels.add(idleChannel);
}
}
return idleTimeoutChannels != null ? idleTimeoutChannels : Collections.<IdleChannel> emptyList();
}
private List<IdleChannel> closeChannels(List<IdleChannel> candidates) {
// lazy create, only if we hit a non-closeable channel
List<IdleChannel> closedChannels = null;
for (int i = 0; i < candidates.size(); i++) {
// We call takeOwnership here to avoid closing a channel that has just been taken out
// of the pool, otherwise we risk closing an active connection.
IdleChannel idleChannel = candidates.get(i);
if (idleChannel.takeOwnership()) {
LOGGER.debug("Closing Idle Channel {}", idleChannel.channel);
close(idleChannel.channel);
if (closedChannels != null) {
closedChannels.add(idleChannel);
}
} else if (closedChannels == null) {
// first non closeable to be skipped, copy all
// previously skipped closeable channels
closedChannels = new ArrayList<>(candidates.size());
for (int j = 0; j < i; j++)
closedChannels.add(candidates.get(j));
}
}
return closedChannels != null ? closedChannels : candidates;
}
public void run(Timeout timeout) throws Exception {
if (isClosed.get())
return;
if (LOGGER.isDebugEnabled())
for (Object key : partitions.keySet()) {
int size = partitions.get(key).size();
if (size > 0) {
LOGGER.debug("Entry count for : {} : {}", key, size);
}
}
long start = unpreciseMillisTime();
int closedCount = 0;
int totalCount = 0;
for (ConcurrentLinkedDeque<IdleChannel> partition : partitions.values()) {
// store in intermediate unsynchronized lists to minimize
// the impact on the ConcurrentLinkedDeque
if (LOGGER.isDebugEnabled())
totalCount += partition.size();
List<IdleChannel> closedChannels = closeChannels(expiredChannels(partition, start));
if (!closedChannels.isEmpty()) {
if (connectionTtlEnabled) {
for (IdleChannel closedChannel : closedChannels)
channelId2Creation.remove(closedChannel.channel.id());
}
partition.removeAll(closedChannels);
closedCount += closedChannels.size();
}
}
if (LOGGER.isDebugEnabled()) {
long duration = unpreciseMillisTime() - start;
if (closedCount > 0) {
LOGGER.debug("Closed {} connections out of {} in {} ms", closedCount, totalCount, duration);
}
}
scheduleNewIdleChannelDetector(timeout.task());
}
}
/**
* {@inheritDoc}
*/
public boolean offer(Channel channel, Object partitionKey) {
if (isClosed.get())
return false;
long now = unpreciseMillisTime();
if (isTtlExpired(channel, now))
return false;
boolean offered = offer0(channel, partitionKey, now);
if (connectionTtlEnabled && offered) {
registerChannelCreation(channel, partitionKey, now);
}
return offered;
}
private boolean offer0(Channel channel, Object partitionKey, long now) {
ConcurrentLinkedDeque<IdleChannel> partition = partitions.get(partitionKey);
if (partition == null) {
partition = partitions.computeIfAbsent(partitionKey, pk -> new ConcurrentLinkedDeque<>());
}
return partition.offerFirst(new IdleChannel(channel, now));
}
private void registerChannelCreation(Channel channel, Object partitionKey, long now) {
ChannelId id = channel.id();
if (!channelId2Creation.containsKey(id)) {
channelId2Creation.putIfAbsent(id, new ChannelCreation(now, partitionKey));
}
}
/**
* {@inheritDoc}
*/
public Channel poll(Object partitionKey) {
IdleChannel idleChannel = null;
ConcurrentLinkedDeque<IdleChannel> partition = partitions.get(partitionKey);
if (partition != null) {
while (idleChannel == null) {
idleChannel = poolLeaseStrategy.lease(partition);
if (idleChannel == null)
// pool is empty
break;
else if (isRemotelyClosed(idleChannel.channel)) {
idleChannel = null;
LOGGER.trace("Channel not connected or not opened, probably remotely closed!");
} else if (!idleChannel.takeOwnership()) {
idleChannel = null;
LOGGER.trace("Couldn't take ownership of channel, probably in the process of being expired!");
}
}
}
return idleChannel != null ? idleChannel.channel : null;
}
/**
* {@inheritDoc}
*/
public boolean removeAll(Channel channel) {
ChannelCreation creation = connectionTtlEnabled ? channelId2Creation.remove(channel.id()) : null;
return !isClosed.get() && creation != null && partitions.get(creation.partitionKey).remove(channel);
}
/**
* {@inheritDoc}
*/
public boolean isOpen() {
return !isClosed.get();
}
/**
* {@inheritDoc}
*/
public void destroy() {
if (isClosed.getAndSet(true))
return;
partitions.clear();
if (connectionTtlEnabled) {
channelId2Creation.clear();
}
}
private void close(Channel channel) {
// FIXME pity to have to do this here
Channels.setDiscard(channel);
if (connectionTtlEnabled) {
channelId2Creation.remove(channel.id());
}
Channels.silentlyCloseChannel(channel);
}
private void flushPartition(Object partitionKey, ConcurrentLinkedDeque<IdleChannel> partition) {
if (partition != null) {
partitions.remove(partitionKey);
for (IdleChannel idleChannel : partition)
close(idleChannel.channel);
}
}
@Override
public void flushPartitions(Predicate<Object> predicate) {
for (Map.Entry<Object, ConcurrentLinkedDeque<IdleChannel>> partitionsEntry : partitions.entrySet()) {
Object partitionKey = partitionsEntry.getKey();
if (predicate.test(partitionKey))
flushPartition(partitionKey, partitionsEntry.getValue());
}
}
@Override
public Map<String, Long> getIdleChannelCountPerHost() {
return partitions
.values()
.stream()
.flatMap(ConcurrentLinkedDeque::stream)
.map(idle -> idle.getChannel().remoteAddress())
.filter(a -> a.getClass() == InetSocketAddress.class)
.map(a -> (InetSocketAddress) a)
.map(InetSocketAddress::getHostName)
.collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
}
public enum PoolLeaseStrategy {
LIFO {
public <E> E lease(Deque<E> d) {
return d.pollFirst();
}
},
FIFO {
public <E> E lease(Deque<E> d) {
return d.pollLast();
}
};
abstract <E> E lease(Deque<E> d);
}
}