org.eclipse.jetty.client.AbstractConnectionPool Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
// which is available at https://www.apache.org/licenses/LICENSE-2.0.
//
// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
// ========================================================================
//
package org.eclipse.jetty.client;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Objects;
import java.util.Queue;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.stream.Collectors;
import org.eclipse.jetty.client.api.Connection;
import org.eclipse.jetty.util.Attachable;
import org.eclipse.jetty.util.Callback;
import org.eclipse.jetty.util.IO;
import org.eclipse.jetty.util.Pool;
import org.eclipse.jetty.util.Promise;
import org.eclipse.jetty.util.annotation.ManagedAttribute;
import org.eclipse.jetty.util.annotation.ManagedObject;
import org.eclipse.jetty.util.component.ContainerLifeCycle;
import org.eclipse.jetty.util.component.Dumpable;
import org.eclipse.jetty.util.thread.Sweeper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static java.util.stream.Collectors.toCollection;
@ManagedObject
public abstract class AbstractConnectionPool extends ContainerLifeCycle implements ConnectionPool, Dumpable, Sweeper.Sweepable
{
private static final Logger LOG = LoggerFactory.getLogger(AbstractConnectionPool.class);
private final AtomicInteger pending = new AtomicInteger();
private final HttpDestination destination;
private final Callback requester;
private final Pool pool;
private boolean maximizeConnections;
private volatile long maxDurationNanos = 0L;
protected AbstractConnectionPool(HttpDestination destination, int maxConnections, boolean cache, Callback requester)
{
this(destination, Pool.StrategyType.FIRST, maxConnections, cache, requester);
}
protected AbstractConnectionPool(HttpDestination destination, Pool.StrategyType strategy, int maxConnections, boolean cache, Callback requester)
{
this(destination, new Pool<>(strategy, maxConnections, cache), requester);
}
protected AbstractConnectionPool(HttpDestination destination, Pool pool, Callback requester)
{
this.destination = destination;
this.requester = requester;
this.pool = pool;
pool.setMaxMultiplex(1); // Force the use of multiplexing.
addBean(pool);
}
@Override
protected void doStop() throws Exception
{
pool.close();
}
@Override
public CompletableFuture preCreateConnections(int connectionCount)
{
if (LOG.isDebugEnabled())
LOG.debug("Pre-creating connections {}/{}", connectionCount, getMaxConnectionCount());
List> futures = new ArrayList<>();
for (int i = 0; i < connectionCount; i++)
{
Pool.Entry entry = pool.reserve();
if (entry == null)
break;
pending.incrementAndGet();
Promise.Completable future = new FutureConnection(entry);
futures.add(future);
if (LOG.isDebugEnabled())
LOG.debug("Pre-creating connection {}/{} at {}", futures.size(), getMaxConnectionCount(), entry);
destination.newConnection(future);
}
return CompletableFuture.allOf(futures.toArray(new CompletableFuture[0]));
}
/**
* Get the max usage duration in milliseconds of the pool's connections.
* Values {@code 0} and negative mean that there is no limit.
* This only guarantees that a connection cannot be acquired after the configured
* duration elapses, so that is only enforced when {@link #acquire(boolean)} is called.
* If a pool stays completely idle for a duration longer than the value
* returned by this method, the max duration will not be enforced.
* It's up to the idle timeout mechanism (see {@link HttpClient#getIdleTimeout()})
* to handle closing idle connections.
*/
@ManagedAttribute(value = "The maximum duration in milliseconds a connection can be used for before it gets closed")
public long getMaxDuration()
{
return TimeUnit.NANOSECONDS.toMillis(maxDurationNanos);
}
public void setMaxDuration(long maxDurationInMs)
{
this.maxDurationNanos = TimeUnit.MILLISECONDS.toNanos(maxDurationInMs);
}
protected int getMaxMultiplex()
{
return pool.getMaxMultiplex();
}
protected void setMaxMultiplex(int maxMultiplex)
{
pool.setMaxMultiplex(maxMultiplex);
}
protected int getMaxUsageCount()
{
return pool.getMaxUsageCount();
}
protected void setMaxUsageCount(int maxUsageCount)
{
pool.setMaxUsageCount(maxUsageCount);
}
@ManagedAttribute(value = "The number of active connections", readonly = true)
public int getActiveConnectionCount()
{
return pool.getInUseCount();
}
@ManagedAttribute(value = "The number of idle connections", readonly = true)
public int getIdleConnectionCount()
{
return pool.getIdleCount();
}
@ManagedAttribute(value = "The max number of connections", readonly = true)
public int getMaxConnectionCount()
{
return pool.getMaxEntries();
}
@ManagedAttribute(value = "The number of connections", readonly = true)
public int getConnectionCount()
{
return pool.size();
}
@ManagedAttribute(value = "The number of pending connections", readonly = true)
public int getPendingConnectionCount()
{
return pending.get();
}
@Override
public boolean isEmpty()
{
return pool.size() == 0;
}
@Override
@ManagedAttribute("Whether this pool is closed")
public boolean isClosed()
{
return pool.isClosed();
}
@ManagedAttribute("Whether the pool tries to maximize the number of connections used")
public boolean isMaximizeConnections()
{
return maximizeConnections;
}
/**
* Sets whether the number of connections should be maximized.
*
* @param maximizeConnections whether the number of connections should be maximized
*/
public void setMaximizeConnections(boolean maximizeConnections)
{
this.maximizeConnections = maximizeConnections;
}
/**
* Returns an idle connection, if available;
* if an idle connection is not available, and the given {@code create} parameter is {@code true}
* or {@link #isMaximizeConnections()} is {@code true},
* then attempts to open a new connection, if possible within the configuration of this
* connection pool (for example, if it does not exceed the max connection count);
* otherwise it attempts to open a new connection, if the number of queued requests is
* greater than the number of pending connections;
* if no connection is available even after the attempts to open, return {@code null}.
* The {@code create} parameter is just a hint: the connection may be created even if
* {@code false}, or may not be created even if {@code true}.
*
* @param create a hint to attempt to open a new connection if no idle connections are available
* @return an idle connection or {@code null} if no idle connections are available
* @see #tryCreate(boolean)
*/
@Override
public Connection acquire(boolean create)
{
if (LOG.isDebugEnabled())
LOG.debug("Acquiring create={} on {}", create, this);
Connection connection = activate();
if (connection == null)
{
tryCreate(create);
connection = activate();
}
return connection;
}
/**
* Tries to create a new connection.
* Whether a new connection is created is determined by the {@code create} parameter
* and a count of demand and supply, where the demand is derived from the number of
* queued requests, and the supply is the number of pending connections time the
* {@link #getMaxMultiplex()} factor: if the demand is less than the supply, the
* connection will not be created.
* Since the number of queued requests used to derive the demand may be a stale
* value, it is possible that few more connections than strictly necessary may be
* created, but enough to satisfy the demand.
*
* @param create a hint to request to create a connection
*/
protected void tryCreate(boolean create)
{
int connectionCount = getConnectionCount();
if (LOG.isDebugEnabled())
LOG.debug("Try creating connection {}/{} with {} pending", connectionCount, getMaxConnectionCount(), getPendingConnectionCount());
// If we have already pending sufficient multiplexed connections, then do not create another.
int multiplexed = getMaxMultiplex();
while (true)
{
int pending = this.pending.get();
int supply = pending * multiplexed;
int demand = destination.getQueuedRequestCount() + (create ? 1 : 0);
boolean tryCreate = isMaximizeConnections() || supply < demand;
if (LOG.isDebugEnabled())
LOG.debug("Try creating({}) connection, pending/demand/supply: {}/{}/{}, result={}", create, pending, demand, supply, tryCreate);
if (!tryCreate)
return;
if (this.pending.compareAndSet(pending, pending + 1))
break;
}
// Create the connection.
Pool.Entry entry = pool.reserve();
if (entry == null)
{
pending.decrementAndGet();
if (LOG.isDebugEnabled())
LOG.debug("Not creating connection as pool is full, pending: {}", pending);
return;
}
if (LOG.isDebugEnabled())
LOG.debug("Creating connection {}/{} at {}", connectionCount, getMaxConnectionCount(), entry);
Promise future = new FutureConnection(entry);
destination.newConnection(future);
}
@Override
public boolean accept(Connection connection)
{
if (!(connection instanceof Attachable))
throw new IllegalArgumentException("Invalid connection object: " + connection);
Pool.Entry entry = pool.reserve();
if (entry == null)
return false;
if (LOG.isDebugEnabled())
LOG.debug("onCreating {} {}", entry, connection);
Attachable attachable = (Attachable)connection;
attachable.setAttachment(new EntryHolder(entry));
onCreated(connection);
entry.enable(connection, false);
idle(connection, false);
return true;
}
protected void proceed()
{
requester.succeeded();
}
protected Connection activate()
{
while (true)
{
Pool.Entry entry = pool.acquire();
if (entry != null)
{
Connection connection = entry.getPooled();
long maxDurationNanos = this.maxDurationNanos;
if (maxDurationNanos > 0L)
{
EntryHolder holder = (EntryHolder)((Attachable)connection).getAttachment();
if (holder.isExpired(maxDurationNanos))
{
boolean canClose = remove(connection);
if (canClose)
IO.close(connection);
if (LOG.isDebugEnabled())
LOG.debug("Connection removed{} due to expiration {} {}", (canClose ? " and closed" : ""), entry, pool);
continue;
}
}
if (LOG.isDebugEnabled())
LOG.debug("Activated {} {}", entry, pool);
acquired(connection);
return connection;
}
return null;
}
}
@Override
public boolean isActive(Connection connection)
{
if (!(connection instanceof Attachable))
throw new IllegalArgumentException("Invalid connection object: " + connection);
Attachable attachable = (Attachable)connection;
EntryHolder holder = (EntryHolder)attachable.getAttachment();
if (holder == null)
return false;
return !holder.entry.isIdle();
}
@Override
public boolean release(Connection connection)
{
if (!deactivate(connection))
return false;
released(connection);
return idle(connection, isClosed());
}
protected boolean deactivate(Connection connection)
{
if (!(connection instanceof Attachable))
throw new IllegalArgumentException("Invalid connection object: " + connection);
Attachable attachable = (Attachable)connection;
EntryHolder holder = (EntryHolder)attachable.getAttachment();
if (holder == null)
return true;
long maxDurationNanos = this.maxDurationNanos;
if (maxDurationNanos > 0L && holder.isExpired(maxDurationNanos))
{
// Remove instead of release if the connection expired.
return !remove(connection);
}
else
{
// Release if the connection has not expired, then remove if not reusable.
boolean reusable = pool.release(holder.entry);
if (LOG.isDebugEnabled())
LOG.debug("Released ({}) {} {}", reusable, holder.entry, pool);
if (reusable)
return true;
return !remove(connection);
}
}
@Override
public boolean remove(Connection connection)
{
if (!(connection instanceof Attachable))
throw new IllegalArgumentException("Invalid connection object: " + connection);
Attachable attachable = (Attachable)connection;
EntryHolder holder = (EntryHolder)attachable.getAttachment();
if (holder == null)
return false;
boolean removed = pool.remove(holder.entry);
if (removed)
attachable.setAttachment(null);
if (LOG.isDebugEnabled())
LOG.debug("Removed ({}) {} {}", removed, holder.entry, pool);
if (removed)
{
released(connection);
removed(connection);
}
return removed;
}
@Deprecated
protected boolean remove(Connection connection, boolean force)
{
return remove(connection);
}
protected void onCreated(Connection connection)
{
}
protected boolean idle(Connection connection, boolean close)
{
return !close;
}
protected void acquired(Connection connection)
{
}
protected void released(Connection connection)
{
}
protected void removed(Connection connection)
{
}
Queue getIdleConnections()
{
return pool.values().stream()
.filter(Pool.Entry::isIdle)
.filter(entry -> !entry.isClosed())
.map(Pool.Entry::getPooled)
.collect(toCollection(ArrayDeque::new));
}
Collection getActiveConnections()
{
return pool.values().stream()
.filter(entry -> !entry.isIdle())
.filter(entry -> !entry.isClosed())
.map(Pool.Entry::getPooled)
.collect(Collectors.toList());
}
@Override
public void close()
{
// Forcibly release and remove entries to do our best effort calling the listeners.
try
{
for (Pool.Entry entry : pool.values())
{
while (entry.isInUse())
{
if (entry.release())
{
released(entry.getPooled());
break;
}
}
if (entry.remove())
removed(entry.getPooled());
}
}
catch (Throwable x)
{
if (LOG.isDebugEnabled())
LOG.debug("Detected concurrent modification while forcibly releasing the pooled connections", x);
// We could not call the listeners for all entries, but at least the following
// pool.close() call will still release all resources.
}
pool.close();
}
@Override
public void dump(Appendable out, String indent) throws IOException
{
Dumpable.dumpObjects(out, indent, this);
}
@Override
public boolean sweep()
{
pool.values().stream()
.map(Pool.Entry::getPooled)
.filter(connection -> connection instanceof Sweeper.Sweepable)
.forEach(connection ->
{
if (((Sweeper.Sweepable)connection).sweep())
{
boolean removed = remove(connection);
LOG.warn("Connection swept: {}{}{} from active connections{}{}",
connection,
System.lineSeparator(),
removed ? "Removed" : "Not removed",
System.lineSeparator(),
dump());
}
});
return false;
}
@Override
public String toString()
{
return String.format("%s@%x[c=%d/%d/%d,a=%d,i=%d,q=%d]",
getClass().getSimpleName(),
hashCode(),
getPendingConnectionCount(),
getConnectionCount(),
getMaxConnectionCount(),
getActiveConnectionCount(),
getIdleConnectionCount(),
destination.getQueuedRequestCount());
}
private class FutureConnection extends Promise.Completable
{
private final Pool.Entry reserved;
public FutureConnection(Pool.Entry reserved)
{
this.reserved = reserved;
}
@Override
public void succeeded(Connection connection)
{
if (LOG.isDebugEnabled())
LOG.debug("Connection creation succeeded {}: {}", reserved, connection);
if (connection instanceof Attachable)
{
((Attachable)connection).setAttachment(new EntryHolder(reserved));
onCreated(connection);
pending.decrementAndGet();
reserved.enable(connection, false);
idle(connection, false);
complete(null);
proceed();
}
else
{
// reduce pending on failure and if not multiplexing also reduce demand
failed(new IllegalArgumentException("Invalid connection object: " + connection));
}
}
@Override
public void failed(Throwable x)
{
if (LOG.isDebugEnabled())
LOG.debug("Connection creation failed {}", reserved, x);
// reduce pending on failure and if not multiplexing also reduce demand
pending.decrementAndGet();
reserved.remove();
completeExceptionally(x);
requester.failed(x);
}
}
private static class EntryHolder
{
private final Pool.Entry entry;
private final long creationTimestamp = System.nanoTime();
private EntryHolder(Pool.Entry entry)
{
this.entry = Objects.requireNonNull(entry);
}
private boolean isExpired(long timeoutNanos)
{
return System.nanoTime() - creationTimestamp >= timeoutNanos;
}
}
}