org.apache.mina.core.polling

Class AbstractPollingIoAcceptor<S extends AbstractIoSession,H>

java.lang.Object

org.apache.mina.core.service.AbstractIoService

org.apache.mina.core.service.AbstractIoAcceptor

org.apache.mina.core.polling.AbstractPollingIoAcceptor<S,H>

All Implemented Interfaces:

IoAcceptor, IoService

Direct Known Subclasses:

NioSocketAcceptor

public abstract class AbstractPollingIoAcceptor<S extends AbstractIoSession,H>
extends AbstractIoAcceptor

A base class for implementing transport using a polling strategy. The underlying sockets will be checked in an active loop and woke up when an socket needed to be processed. This class handle the logic behind binding, accepting and disposing the server sockets. An Executor will be used for running client accepting and an AbstractPollingIoProcessor will be used for processing client I/O operations like reading, writing and closing. All the low level methods for binding, accepting, closing need to be provided by the subclassing implementation.

See Also:

for a example of implementation

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	AbstractPollingIoAcceptor.Acceptor This class is called by the startupAcceptor() method and is placed into a NamePreservingRunnable class.

Nested classes/interfaces inherited from class org.apache.mina.core.service.AbstractIoAcceptor

AbstractIoAcceptor.AcceptorOperationFuture

Nested classes/interfaces inherited from class org.apache.mina.core.service.AbstractIoService

AbstractIoService.ServiceOperationFuture

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.concurrent.atomic.AtomicReference<AbstractPollingIoAcceptor.Acceptor>	acceptorRef The thread responsible of accepting incoming requests
protected int	backlog Define the number of socket that can wait to be accepted.
private java.util.Map<java.net.SocketAddress,H>	boundHandles
private java.util.Queue<AbstractIoAcceptor.AcceptorOperationFuture>	cancelQueue
private boolean	createdProcessor
private AbstractIoService.ServiceOperationFuture	disposalFuture
private java.util.concurrent.Semaphore	lock A lock used to protect the selector to be waked up before it's created
private IoProcessor<S>	processor
private java.util.Queue<AbstractIoAcceptor.AcceptorOperationFuture>	registerQueue
protected boolean	reuseAddress
private boolean	selectable A flag set when the acceptor has been created and initialized

Fields inherited from class org.apache.mina.core.service.AbstractIoAcceptor

bindLock

Fields inherited from class org.apache.mina.core.service.AbstractIoService

disposalLock, sessionConfig

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractPollingIoAcceptor(IoSessionConfig sessionConfig, java.lang.Class<? extends IoProcessor<S>> processorClass) Constructor for AbstractPollingIoAcceptor.
protected	AbstractPollingIoAcceptor(IoSessionConfig sessionConfig, java.lang.Class<? extends IoProcessor<S>> processorClass, int processorCount) Constructor for AbstractPollingIoAcceptor.
protected	AbstractPollingIoAcceptor(IoSessionConfig sessionConfig, java.lang.Class<? extends IoProcessor<S>> processorClass, int processorCount, java.nio.channels.spi.SelectorProvider selectorProvider) Constructor for AbstractPollingIoAcceptor.
protected	AbstractPollingIoAcceptor(IoSessionConfig sessionConfig, java.util.concurrent.Executor executor, IoProcessor<S> processor) Constructor for AbstractPollingIoAcceptor.
private	AbstractPollingIoAcceptor(IoSessionConfig sessionConfig, java.util.concurrent.Executor executor, IoProcessor<S> processor, boolean createdProcessor, java.nio.channels.spi.SelectorProvider selectorProvider) Constructor for AbstractPollingIoAcceptor.
protected	AbstractPollingIoAcceptor(IoSessionConfig sessionConfig, IoProcessor<S> processor) Constructor for AbstractPollingIoAcceptor.

Method Summary

Modifier and Type	Method and Description
protected abstract S	accept(IoProcessor<S> processor, H handle) Accept a client connection for a server socket and return a new IoSession associated with the given IoProcessor
protected java.util.Set<java.net.SocketAddress>	bindInternal(java.util.List<? extends java.net.SocketAddress> localAddresses) Starts the acceptor, and register the given addresses
protected abstract void	close(H handle) Close a server socket.
protected abstract void	destroy() Destroy the polling system, will be called when this IoAcceptor implementation will be disposed.
protected void	dispose0() Implement this method to release any acquired resources.
int	getBacklog()
SocketSessionConfig	getSessionConfig() Returns the default configuration of the new IoSessions created by this service.
protected abstract void	init() Initialize the polling system, will be called at construction time.
protected abstract void	init(java.nio.channels.spi.SelectorProvider selectorProvider) Initialize the polling system, will be called at construction time.
boolean	isReuseAddress()
protected abstract java.net.SocketAddress	localAddress(H handle) Get the local address associated with a given server socket
IoSession	newSession(java.net.SocketAddress remoteAddress, java.net.SocketAddress localAddress) (Optional) Returns an IoSession that is bound to the specified localAddress and the specified remoteAddress which reuses the local address that is already bound by this service.
protected abstract H	open(java.net.SocketAddress localAddress) Open a server socket for a given local address.
private int	registerHandles() Sets up the socket communications.
protected abstract int	select() Check for acceptable connections, interrupt when at least a server is ready for accepting.
protected abstract java.util.Iterator<H>	selectedHandles() Iterator for the set of server sockets found with acceptable incoming connections during the last select() call.
void	setBacklog(int backlog) Sets the Backlog parameter
void	setReuseAddress(boolean reuseAddress) Set the Reuse Address flag
private void	startupAcceptor() This method is called by the doBind() and doUnbind() methods.
protected void	unbind0(java.util.List<? extends java.net.SocketAddress> localAddresses) Implement this method to perform the actual unbind operation.
private int	unregisterHandles() This method just checks to see if anything has been placed into the cancellation queue.
protected abstract void	wakeup() Interrupt the select() method.

Methods inherited from class org.apache.mina.core.service.AbstractIoAcceptor

bind, bind, bind, bind, bind, getDefaultLocalAddress, getDefaultLocalAddresses, getLocalAddress, getLocalAddresses, isCloseOnDeactivation, setCloseOnDeactivation, setDefaultLocalAddress, setDefaultLocalAddresses, setDefaultLocalAddresses, setDefaultLocalAddresses, toString, unbind, unbind, unbind, unbind

Methods inherited from class org.apache.mina.core.service.AbstractIoService

addListener, broadcast, dispose, dispose, executeWorker, executeWorker, finishSessionInitialization0, getActivationTime, getFilterChain, getFilterChainBuilder, getHandler, getListeners, getManagedSessionCount, getManagedSessions, getScheduledWriteBytes, getScheduledWriteMessages, getSessionDataStructureFactory, getStatistics, initSession, isActive, isDisposed, isDisposing, removeListener, setFilterChainBuilder, setHandler, setSessionDataStructureFactory

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.mina.core.service.IoService

addListener, broadcast, dispose, dispose, getActivationTime, getFilterChain, getFilterChainBuilder, getHandler, getManagedSessionCount, getManagedSessions, getScheduledWriteBytes, getScheduledWriteMessages, getSessionDataStructureFactory, getStatistics, getTransportMetadata, isActive, isDisposed, isDisposing, removeListener, setFilterChainBuilder, setHandler, setSessionDataStructureFactory

Field Detail

lock

private final java.util.concurrent.Semaphore lock

A lock used to protect the selector to be waked up before it's created

processor

private final IoProcessor<S extends AbstractIoSession> processor

createdProcessor

private final boolean createdProcessor

registerQueue

private final java.util.Queue<AbstractIoAcceptor.AcceptorOperationFuture> registerQueue

cancelQueue

private final java.util.Queue<AbstractIoAcceptor.AcceptorOperationFuture> cancelQueue

boundHandles

private final java.util.Map<java.net.SocketAddress,H> boundHandles

disposalFuture

private final AbstractIoService.ServiceOperationFuture disposalFuture

selectable

private volatile boolean selectable

A flag set when the acceptor has been created and initialized

acceptorRef

private java.util.concurrent.atomic.AtomicReference<AbstractPollingIoAcceptor.Acceptor> acceptorRef

The thread responsible of accepting incoming requests

reuseAddress

protected boolean reuseAddress

backlog

protected int backlog

Define the number of socket that can wait to be accepted. Default to 50 (as in the SocketServer default).

Constructor Detail

AbstractPollingIoAcceptor

protected AbstractPollingIoAcceptor(IoSessionConfig sessionConfig,
                                    java.lang.Class<? extends IoProcessor<S>> processorClass)

Constructor for AbstractPollingIoAcceptor. You need to provide a default session configuration, a class of IoProcessor which will be instantiated in a SimpleIoProcessorPool for better scaling in multiprocessor systems. The default pool size will be used.

Parameters:

sessionConfig - the default configuration for the managed IoSession

processorClass - a Class of IoProcessor for the associated IoSession type.

See Also:

SimpleIoProcessorPool

AbstractPollingIoAcceptor

protected AbstractPollingIoAcceptor(IoSessionConfig sessionConfig,
                                    java.lang.Class<? extends IoProcessor<S>> processorClass,
                                    int processorCount)

Constructor for AbstractPollingIoAcceptor. You need to provide a default session configuration, a class of IoProcessor which will be instantiated in a SimpleIoProcessorPool for using multiple thread for better scaling in multiprocessor systems.

Parameters:

sessionConfig - the default configuration for the managed IoSession

processorClass - a Class of IoProcessor for the associated IoSession type.

processorCount - the amount of processor to instantiate for the pool

See Also:

SimpleIoProcessorPool

AbstractPollingIoAcceptor

protected AbstractPollingIoAcceptor(IoSessionConfig sessionConfig,
                                    java.lang.Class<? extends IoProcessor<S>> processorClass,
                                    int processorCount,
                                    java.nio.channels.spi.SelectorProvider selectorProvider)

Constructor for AbstractPollingIoAcceptor. You need to provide a default session configuration, a class of IoProcessor which will be instantiated in a SimpleIoProcessorPool for using multiple thread for better scaling in multiprocessor systems.

Parameters:

sessionConfig - the default configuration for the managed IoSession

processorClass - a Class�of IoProcessor for the associated IoSession type.

processorCount - the amount of processor to instantiate for the pool

selectorProvider - The SelectorProvider to use

See Also:

SimpleIoProcessorPool

AbstractPollingIoAcceptor

protected AbstractPollingIoAcceptor(IoSessionConfig sessionConfig,
                                    IoProcessor<S> processor)

Constructor for AbstractPollingIoAcceptor. You need to provide a default session configuration, a default Executor will be created using Executors.newCachedThreadPool().

Parameters:

sessionConfig - the default configuration for the managed IoSession

processor - the IoProcessor for processing the IoSession of this transport, triggering events to the bound IoHandler and processing the chains of IoFilter

See Also:

AbstractIoService

AbstractPollingIoAcceptor

protected AbstractPollingIoAcceptor(IoSessionConfig sessionConfig,
                                    java.util.concurrent.Executor executor,
                                    IoProcessor<S> processor)

Constructor for AbstractPollingIoAcceptor. You need to provide a default session configuration and an Executor for handling I/O events. If a null Executor is provided, a default one will be created using Executors.newCachedThreadPool().

Parameters:

sessionConfig - the default configuration for the managed IoSession

executor - the Executor used for handling asynchronous execution of I/O events. Can be null.

processor - the IoProcessor for processing the IoSession of this transport, triggering events to the bound IoHandler and processing the chains of IoFilter

See Also:

AbstractIoService(IoSessionConfig, Executor)

AbstractPollingIoAcceptor

private AbstractPollingIoAcceptor(IoSessionConfig sessionConfig,
                                  java.util.concurrent.Executor executor,
                                  IoProcessor<S> processor,
                                  boolean createdProcessor,
                                  java.nio.channels.spi.SelectorProvider selectorProvider)

Constructor for AbstractPollingIoAcceptor. You need to provide a default session configuration and an Executor for handling I/O events. If a null Executor is provided, a default one will be created using Executors.newCachedThreadPool().

Parameters:

sessionConfig - the default configuration for the managed IoSession

executor - the Executor used for handling asynchronous execution of I/O events. Can be null.

processor - the IoProcessor for processing the IoSession of this transport, triggering events to the bound IoHandler and processing the chains of IoFilter

createdProcessor - tagging the processor as automatically created, so it will be automatically disposed

See Also:

AbstractIoService(IoSessionConfig, Executor)

Method Detail

init

protected abstract void init()
                      throws java.lang.Exception

Initialize the polling system, will be called at construction time.

Throws:

java.lang.Exception - any exception thrown by the underlying system calls

init

protected abstract void init(java.nio.channels.spi.SelectorProvider selectorProvider)
                      throws java.lang.Exception

Initialize the polling system, will be called at construction time.

Throws:

java.lang.Exception - any exception thrown by the underlying system calls

destroy

protected abstract void destroy()
                         throws java.lang.Exception

Destroy the polling system, will be called when this IoAcceptor implementation will be disposed.

Throws:

java.lang.Exception - any exception thrown by the underlying systems calls

select

protected abstract int select()
                       throws java.lang.Exception

Check for acceptable connections, interrupt when at least a server is ready for accepting. All the ready server socket descriptors need to be returned by selectedHandles()

Returns:

The number of sockets having got incoming client

Throws:

java.lang.Exception - any exception thrown by the underlying systems calls

wakeup

protected abstract void wakeup()

Interrupt the select() method. Used when the poll set need to be modified.

selectedHandles

protected abstract java.util.Iterator<H> selectedHandles()

Iterator for the set of server sockets found with acceptable incoming connections during the last select() call.

Returns:

the list of server handles ready

open

protected abstract H open(java.net.SocketAddress localAddress)
                   throws java.lang.Exception

Open a server socket for a given local address.

Parameters:

localAddress - the associated local address

Returns:

the opened server socket

Throws:

java.lang.Exception - any exception thrown by the underlying systems calls

localAddress

protected abstract java.net.SocketAddress localAddress(H handle)
                                                throws java.lang.Exception

Get the local address associated with a given server socket

Parameters:

handle - the server socket

Returns:

the local SocketAddress associated with this handle

Throws:

java.lang.Exception - any exception thrown by the underlying systems calls

accept

protected abstract S accept(IoProcessor<S> processor,
                            H handle)
                     throws java.lang.Exception

Accept a client connection for a server socket and return a new IoSession associated with the given IoProcessor

Parameters:

processor - the IoProcessor to associate with the IoSession

handle - the server handle

Returns:

the created IoSession

Throws:

java.lang.Exception - any exception thrown by the underlying systems calls

close

protected abstract void close(H handle)
                       throws java.lang.Exception

Close a server socket.

Parameters:

handle - the server socket

Throws:

java.lang.Exception - any exception thrown by the underlying systems calls

dispose0

protected void dispose0()
                 throws java.lang.Exception

Implement this method to release any acquired resources. This method is invoked only once by AbstractIoService.dispose().

Specified by:

dispose0 in class AbstractIoService

Throws:

java.lang.Exception

bindInternal

protected final java.util.Set<java.net.SocketAddress> bindInternal(java.util.List<? extends java.net.SocketAddress> localAddresses)
                                                            throws java.lang.Exception

Starts the acceptor, and register the given addresses

Specified by:

bindInternal in class AbstractIoAcceptor

Returns:

the Set of the local addresses which is bound actually

Throws:

java.lang.Exception

startupAcceptor

private void startupAcceptor()
                      throws java.lang.InterruptedException

This method is called by the doBind() and doUnbind() methods. If the acceptor is null, the acceptor object will be created and kicked off by the executor. If the acceptor object is null, probably already created and this class is now working, then nothing will happen and the method will just return.

Throws:

java.lang.InterruptedException

unbind0

protected final void unbind0(java.util.List<? extends java.net.SocketAddress> localAddresses)
                      throws java.lang.Exception

Implement this method to perform the actual unbind operation.

Specified by:

unbind0 in class AbstractIoAcceptor

Throws:

java.lang.Exception

registerHandles

private int registerHandles()

Sets up the socket communications. Sets items such as:

Blocking Reuse address Receive buffer size Bind to listen port Registers OP_ACCEPT for selector

unregisterHandles

private int unregisterHandles()

This method just checks to see if anything has been placed into the cancellation queue. The only thing that should be in the cancelQueue is CancellationRequest objects and the only place this happens is in the doUnbind() method.

newSession

public final IoSession newSession(java.net.SocketAddress remoteAddress,
                                  java.net.SocketAddress localAddress)

(Optional) Returns an IoSession that is bound to the specified localAddress and the specified remoteAddress which reuses the local address that is already bound by this service.

This operation is optional. Please throw UnsupportedOperationException if the transport type doesn't support this operation. This operation is usually implemented for connectionless transport types.

getBacklog

public int getBacklog()

Returns:

the backLog

setBacklog

public void setBacklog(int backlog)

Sets the Backlog parameter

Parameters:

backlog - the backlog variable

isReuseAddress

public boolean isReuseAddress()

Returns:

the flag that sets the reuseAddress information

setReuseAddress

public void setReuseAddress(boolean reuseAddress)

Set the Reuse Address flag

Parameters:

reuseAddress - The flag to set

getSessionConfig

public SocketSessionConfig getSessionConfig()

Returns the default configuration of the new IoSessions created by this service.