Class SimpleChannelPool

java.lang.Object

io.netty.channel.pool.SimpleChannelPool

All Implemented Interfaces:

ChannelPool, Closeable, AutoCloseable

Direct Known Subclasses:

FixedChannelPool

public class SimpleChannelPool
extends Object
implements ChannelPool

Simple ChannelPool implementation which will create new Channels if someone tries to acquire a Channel but none is in the pool atm. No limit on the maximal concurrent Channels is enforced. This implementation uses LIFO order for Channels in the ChannelPool.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	SimpleChannelPool.ChannelPoolFullException

Field Summary

Fields

Modifier and Type	Field	Description
private final Bootstrap	bootstrap
private final Deque<Channel>	deque
private final ChannelPoolHandler	handler
private final ChannelHealthChecker	healthCheck
private final boolean	lastRecentUsed
private static final AttributeKey<SimpleChannelPool>	POOL_KEY
private final boolean	releaseHealthCheck

Constructor Summary

Constructors

Constructor	Description
SimpleChannelPool(Bootstrap bootstrap, ChannelPoolHandler handler)	Creates a new instance using the ChannelHealthChecker.ACTIVE.
SimpleChannelPool(Bootstrap bootstrap, ChannelPoolHandler handler, ChannelHealthChecker healthCheck)	Creates a new instance.
SimpleChannelPool(Bootstrap bootstrap, ChannelPoolHandler handler, ChannelHealthChecker healthCheck, boolean releaseHealthCheck)	Creates a new instance.
SimpleChannelPool(Bootstrap bootstrap, ChannelPoolHandler handler, ChannelHealthChecker healthCheck, boolean releaseHealthCheck, boolean lastRecentUsed)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
final Future<Channel>	acquire()	Acquire a Channel from this ChannelPool.
Future<Channel>	acquire(Promise<Channel> promise)	Acquire a Channel from this ChannelPool.
private Future<Channel>	acquireHealthyFromPoolOrNew(Promise<Channel> promise)	Tries to retrieve healthy channel from the pool if any or creates a new channel otherwise.
protected Bootstrap	bootstrap()	Returns the Bootstrap this pool will use to open new connections.
void	close()
private void	closeAndFail(Channel channel, Throwable cause, Promise<?> promise)
Future<Void>	closeAsync()	Closes the pool in an async manner.
private void	closeChannel(Channel channel)
protected ChannelFuture	connectChannel(Bootstrap bs)	Bootstrap a new Channel.
private void	doHealthCheck(Channel channel, Promise<Channel> promise)
private void	doHealthCheckOnRelease(Channel channel, Promise<Void> promise)
private void	doReleaseChannel(Channel channel, Promise<Void> promise)
protected ChannelPoolHandler	handler()	Returns the ChannelPoolHandler that will be notified for the different pool actions.
protected ChannelHealthChecker	healthChecker()	Returns the ChannelHealthChecker that will be used to check if a Channel is healthy.
private void	notifyConnect(ChannelFuture future, Promise<Channel> promise)
private void	notifyHealthCheck(Future<Boolean> future, Channel channel, Promise<Channel> promise)
protected boolean	offerChannel(Channel channel)	Offer a Channel back to the internal storage.
protected Channel	pollChannel()	Poll a Channel out of the internal storage to reuse it.
final Future<Void>	release(Channel channel)	Release a Channel back to this ChannelPool.
Future<Void>	release(Channel channel, Promise<Void> promise)	Release a Channel back to this ChannelPool.
private void	releaseAndOffer(Channel channel, Promise<Void> promise)
private void	releaseAndOfferIfHealthy(Channel channel, Promise<Void> promise, Future<Boolean> future)	Adds the channel back to the pool only if the channel is healthy.
protected boolean	releaseHealthCheck()	Indicates whether this pool will check the health of channels before offering them back into the pool.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

POOL_KEY

private static final AttributeKey<SimpleChannelPool> POOL_KEY

deque

private final Deque<Channel> deque

handler

private final ChannelPoolHandler handler

healthCheck

private final ChannelHealthChecker healthCheck

bootstrap

private final Bootstrap bootstrap

releaseHealthCheck

private final boolean releaseHealthCheck

lastRecentUsed

private final boolean lastRecentUsed

Constructor Details

SimpleChannelPool

public SimpleChannelPool(Bootstrap bootstrap,
 ChannelPoolHandler handler)

Creates a new instance using the ChannelHealthChecker.ACTIVE.

Parameters:

bootstrap - the Bootstrap that is used for connections

handler - the ChannelPoolHandler that will be notified for the different pool actions

SimpleChannelPool

public SimpleChannelPool(Bootstrap bootstrap,
 ChannelPoolHandler handler,
 ChannelHealthChecker healthCheck)

Creates a new instance.

Parameters:

bootstrap - the Bootstrap that is used for connections

handler - the ChannelPoolHandler that will be notified for the different pool actions

healthCheck - the ChannelHealthChecker that will be used to check if a Channel is still healthy when obtain from the ChannelPool

SimpleChannelPool

public SimpleChannelPool(Bootstrap bootstrap,
 ChannelPoolHandler handler,
 ChannelHealthChecker healthCheck,
 boolean releaseHealthCheck)

Creates a new instance.

Parameters:

bootstrap - the Bootstrap that is used for connections

handler - the ChannelPoolHandler that will be notified for the different pool actions

healthCheck - the ChannelHealthChecker that will be used to check if a Channel is still healthy when obtain from the ChannelPool

releaseHealthCheck - will check channel health before offering back if this parameter set to true; otherwise, channel health is only checked at acquisition time

SimpleChannelPool

public SimpleChannelPool(Bootstrap bootstrap,
 ChannelPoolHandler handler,
 ChannelHealthChecker healthCheck,
 boolean releaseHealthCheck,
 boolean lastRecentUsed)

Creates a new instance.

Parameters:

bootstrap - the Bootstrap that is used for connections

handler - the ChannelPoolHandler that will be notified for the different pool actions

healthCheck - the ChannelHealthChecker that will be used to check if a Channel is still healthy when obtain from the ChannelPool

releaseHealthCheck - will check channel health before offering back if this parameter set to true; otherwise, channel health is only checked at acquisition time

lastRecentUsed - true Channel selection will be LIFO, if false FIFO.

Method Details

bootstrap

protected Bootstrap bootstrap()

Returns the Bootstrap this pool will use to open new connections.

Returns:

the Bootstrap this pool will use to open new connections

handler

protected ChannelPoolHandler handler()

Returns the ChannelPoolHandler that will be notified for the different pool actions.

Returns:

the ChannelPoolHandler that will be notified for the different pool actions

healthChecker

protected ChannelHealthChecker healthChecker()

Returns the ChannelHealthChecker that will be used to check if a Channel is healthy.

Returns:

the ChannelHealthChecker that will be used to check if a Channel is healthy

releaseHealthCheck

protected boolean releaseHealthCheck()

Indicates whether this pool will check the health of channels before offering them back into the pool.

Returns:

true if this pool will check the health of channels before offering them back into the pool, or false if channel health is only checked at acquisition time

acquire

public final Future<Channel> acquire()

Description copied from interface: ChannelPool

Acquire a Channel from this ChannelPool. The returned Future is notified once the acquire is successful and failed otherwise. Its important that an acquired is always released to the pool again, even if the Channel is explicitly closed..

Specified by:

acquire in interface ChannelPool

acquire

public Future<Channel> acquire(Promise<Channel> promise)

Description copied from interface: ChannelPool

Acquire a Channel from this ChannelPool. The given Promise is notified once the acquire is successful and failed otherwise. Its important that an acquired is always released to the pool again, even if the Channel is explicitly closed..

Specified by:

acquire in interface ChannelPool

acquireHealthyFromPoolOrNew

private Future<Channel> acquireHealthyFromPoolOrNew(Promise<Channel> promise)

Tries to retrieve healthy channel from the pool if any or creates a new channel otherwise.

Parameters:

promise - the promise to provide acquire result.

Returns:

future for acquiring a channel.

notifyConnect

private void notifyConnect(ChannelFuture future,
 Promise<Channel> promise)

doHealthCheck

private void doHealthCheck(Channel channel,
 Promise<Channel> promise)

notifyHealthCheck

private void notifyHealthCheck(Future<Boolean> future,
 Channel channel,
 Promise<Channel> promise)

connectChannel

protected ChannelFuture connectChannel(Bootstrap bs)

Bootstrap a new Channel. The default implementation uses Bootstrap.connect(), sub-classes may override this.

The Bootstrap that is passed in here is cloned via Bootstrap.clone(), so it is safe to modify.

release

public final Future<Void> release(Channel channel)

Description copied from interface: ChannelPool

Release a Channel back to this ChannelPool. The returned Future is notified once the release is successful and failed otherwise. When failed the Channel will automatically closed.

Specified by:

release in interface ChannelPool

release

public Future<Void> release(Channel channel,
 Promise<Void> promise)

Description copied from interface: ChannelPool

Release a Channel back to this ChannelPool. The given Promise is notified once the release is successful and failed otherwise. When failed the Channel will automatically closed.

Specified by:

release in interface ChannelPool

doReleaseChannel

private void doReleaseChannel(Channel channel,
 Promise<Void> promise)

doHealthCheckOnRelease

private void doHealthCheckOnRelease(Channel channel,
 Promise<Void> promise)
                             throws Exception

Throws:

Exception

releaseAndOfferIfHealthy

private void releaseAndOfferIfHealthy(Channel channel,
 Promise<Void> promise,
 Future<Boolean> future)

Adds the channel back to the pool only if the channel is healthy.

Parameters:

channel - the channel to put back to the pool

promise - offer operation promise.

future - the future that contains information fif channel is healthy or not.

Throws:

Exception - in case when failed to notify handler about release operation.

releaseAndOffer

private void releaseAndOffer(Channel channel,
 Promise<Void> promise)
                      throws Exception

Throws:

Exception

closeChannel

private void closeChannel(Channel channel)
                   throws Exception

Throws:

Exception

closeAndFail

private void closeAndFail(Channel channel,
 Throwable cause,
 Promise<?> promise)

pollChannel

protected Channel pollChannel()

Poll a Channel out of the internal storage to reuse it. This will return null if no Channel is ready to be reused. Sub-classes may override pollChannel() and offerChannel(Channel). Be aware that implementations of these methods needs to be thread-safe!

offerChannel

protected boolean offerChannel(Channel channel)

Offer a Channel back to the internal storage. This will return true if the Channel could be added, false otherwise. Sub-classes may override pollChannel() and offerChannel(Channel). Be aware that implementations of these methods needs to be thread-safe!

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface ChannelPool

Specified by:

close in interface Closeable

closeAsync

public Future<Void> closeAsync()

Closes the pool in an async manner.

Returns:

Future which represents completion of the close task