org.apache.mina.core.polling

Class AbstractPollingIoProcessor<S extends AbstractIoSession>

java.lang.Object

org.apache.mina.core.polling.AbstractPollingIoProcessor<S>

Type Parameters:

S - the type of the IoSession this processor can handle

All Implemented Interfaces:

IoProcessor<S>

Direct Known Subclasses:

AprIoProcessor, NioProcessor

public abstract class AbstractPollingIoProcessor<S extends AbstractIoSession>
extends Object
implements IoProcessor<S>

An abstract implementation of IoProcessor which helps transport developers to write an IoProcessor easily. This class is in charge of active polling a set of IoSession and trigger events when some I/O operation is possible.

Author:

Apache MINA Project

Field Summary

Fields

Modifier and Type	Field and Description
protected AtomicBoolean	wakeupCalled

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractPollingIoProcessor(Executor executor) Create an AbstractPollingIoProcessor with the given Executor for handling I/Os events.

Method Summary

Modifier and Type	Method and Description
void	add(S session) Adds the specified session to the I/O processor so that the I/O processor starts to perform any I/O operations related with the session.
protected abstract Iterator<S>	allSessions() Get an Iterator for the list of IoSession polled by this IoProcessor
protected abstract int	allSessionsCount() Get the number of IoSession polled by this IoProcessor
protected abstract void	destroy(S session) Destroy the underlying client socket handle
void	dispose() Releases any resources allocated by this processor.
protected abstract void	doDispose() Dispose the resources used by this IoProcessor for polling the client connections.
void	flush(S session) Flushes the internal write request queue of the specified session.
protected abstract SessionState	getState(S session) Get the state of a session (One of OPENING, OPEN, CLOSING)
protected abstract void	init(S session) Initialize the polling of a session.
protected abstract boolean	isBrokenConnection() Check that the select() has not exited immediately just because of a broken connection.
boolean	isDisposed()
boolean	isDisposing()
protected abstract boolean	isInterestedInRead(S session) Tells if this session is registered for reading
protected abstract boolean	isInterestedInWrite(S session) Tells if this session is registered for writing
protected abstract boolean	isReadable(S session) Tells if the session ready for reading
protected abstract boolean	isSelectorEmpty() Say if the list of IoSession polled by this IoProcessor is empty
protected abstract boolean	isWritable(S session) Tells if the session ready for writing
protected abstract int	read(S session, IoBuffer buf) Reads a sequence of bytes from a IoSession into the given IoBuffer.
protected abstract void	registerNewSelector() In the case we are using the java select() method, this method is used to trash the buggy selector and create a new one, registring all the sockets on it.
void	remove(S session) Removes and closes the specified session from the I/O processor so that the I/O processor closes the connection associated with the session and releases any other related resources.
protected abstract int	select() poll those sessions forever
protected abstract int	select(long timeout) poll those sessions for the given timeout
protected abstract Iterator<S>	selectedSessions() Get an Iterator for the list of IoSession found selected by the last call of select(long)
protected abstract void	setInterestedInRead(S session, boolean isInterested) Set the session to be informed when a read event should be processed
protected abstract void	setInterestedInWrite(S session, boolean isInterested) Set the session to be informed when a write event should be processed
protected abstract int	transferFile(S session, FileRegion region, int length) Write a part of a file to a IoSession, if the underlying API isn't supporting system calls like sendfile(), you can throw a UnsupportedOperationException so the file will be send using usual write(AbstractIoSession, IoBuffer, int) call.
void	updateTrafficControl(S session) Controls the traffic of the specified session depending of the IoSession.isReadSuspended() and IoSession.isWriteSuspended() flags
void	updateTrafficMask(S session) Updates the traffic mask for a given session
protected abstract void	wakeup() Interrupt the select(long) call.
protected abstract int	write(S session, IoBuffer buf, int length) Write a sequence of bytes to a IoSession, means to be called when a session was found ready for writing.
void	write(S session, WriteRequest writeRequest) Writes the WriteRequest for the specified session.

Methods inherited from class java.lang.Object

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

Field Detail

wakeupCalled

protected AtomicBoolean wakeupCalled

Constructor Detail

AbstractPollingIoProcessor

protected AbstractPollingIoProcessor(Executor executor)

Create an AbstractPollingIoProcessor with the given Executor for handling I/Os events.

Parameters:

executor - the Executor for handling I/O events

Method Detail

isDisposing

public final boolean isDisposing()

Specified by:

isDisposing in interface IoProcessor<S extends AbstractIoSession>

Returns:

true if and if only IoProcessor.dispose() method has been called. Please note that this method will return true even after all the related resources are released.

isDisposed

public final boolean isDisposed()

Specified by:

isDisposed in interface IoProcessor<S extends AbstractIoSession>

Returns:

true if and if only all resources of this processor have been disposed.

dispose

public final void dispose()

Releases any resources allocated by this processor. Please note that the resources might not be released as long as there are any sessions managed by this processor. Most implementations will close all sessions immediately and release the related resources.

Specified by:

dispose in interface IoProcessor<S extends AbstractIoSession>

doDispose

protected abstract void doDispose()
                           throws Exception

Dispose the resources used by this IoProcessor for polling the client connections. The implementing class doDispose method will be called.

Throws:

Exception - if some low level IO error occurs

select

protected abstract int select(long timeout)
                       throws Exception

poll those sessions for the given timeout

Parameters:

timeout - milliseconds before the call timeout if no event appear

Returns:

The number of session ready for read or for write

Throws:

Exception - if some low level IO error occurs

select

protected abstract int select()
                       throws Exception

poll those sessions forever

Returns:

The number of session ready for read or for write

Throws:

Exception - if some low level IO error occurs

isSelectorEmpty

protected abstract boolean isSelectorEmpty()

Say if the list of IoSession polled by this IoProcessor is empty

Returns:

true if at least a session is managed by this IoProcessor

wakeup

protected abstract void wakeup()

Interrupt the select(long) call.

allSessions

protected abstract Iterator<S> allSessions()

Get an Iterator for the list of IoSession polled by this IoProcessor

Returns:

Iterator of IoSession

allSessionsCount

protected abstract int allSessionsCount()

Get the number of IoSession polled by this IoProcessor

Returns:

the number of sessions attached to this IoProcessor

selectedSessions

protected abstract Iterator<S> selectedSessions()

Get an Iterator for the list of IoSession found selected by the last call of select(long)

Returns:

Iterator of IoSession read for I/Os operation

getState

protected abstract SessionState getState(S session)

Get the state of a session (One of OPENING, OPEN, CLOSING)

Parameters:

session - the IoSession to inspect

Returns:

the state of the session

isWritable

protected abstract boolean isWritable(S session)

Tells if the session ready for writing

Parameters:

session - the queried session

Returns:

true is ready, false if not ready

isReadable

protected abstract boolean isReadable(S session)

Tells if the session ready for reading

Parameters:

session - the queried session

Returns:

true is ready, false if not ready

setInterestedInWrite

protected abstract void setInterestedInWrite(S session,
                                             boolean isInterested)
                                      throws Exception

Set the session to be informed when a write event should be processed

Parameters:

session - the session for which we want to be interested in write events

isInterested - true for registering, false for removing

Throws:

Exception - If there was a problem while registering the session

setInterestedInRead

protected abstract void setInterestedInRead(S session,
                                            boolean isInterested)
                                     throws Exception

Set the session to be informed when a read event should be processed

Parameters:

session - the session for which we want to be interested in read events

isInterested - true for registering, false for removing

Throws:

Exception - If there was a problem while registering the session

isInterestedInRead

protected abstract boolean isInterestedInRead(S session)

Tells if this session is registered for reading

Parameters:

session - the queried session

Returns:

true is registered for reading

isInterestedInWrite

protected abstract boolean isInterestedInWrite(S session)

Tells if this session is registered for writing

Parameters:

session - the queried session

Returns:

true is registered for writing

init

protected abstract void init(S session)
                      throws Exception

Initialize the polling of a session. Add it to the polling process.

Parameters:

session - the IoSession to add to the polling

Throws:

Exception - any exception thrown by the underlying system calls

destroy

protected abstract void destroy(S session)
                         throws Exception

Destroy the underlying client socket handle

Parameters:

session - the IoSession

Throws:

Exception - any exception thrown by the underlying system calls

read

protected abstract int read(S session,
                            IoBuffer buf)
                     throws Exception

Reads a sequence of bytes from a IoSession into the given IoBuffer. Is called when the session was found ready for reading.

Parameters:

session - the session to read

buf - the buffer to fill

Returns:

the number of bytes read

Throws:

Exception - any exception thrown by the underlying system calls

write

protected abstract int write(S session,
                             IoBuffer buf,
                             int length)
                      throws IOException

Write a sequence of bytes to a IoSession, means to be called when a session was found ready for writing.

Parameters:

session - the session to write

buf - the buffer to write

length - the number of bytes to write can be superior to the number of bytes remaining in the buffer

Returns:

the number of byte written

Throws:

IOException - any exception thrown by the underlying system calls

transferFile

protected abstract int transferFile(S session,
                                    FileRegion region,
                                    int length)
                             throws Exception

Write a part of a file to a IoSession, if the underlying API isn't supporting system calls like sendfile(), you can throw a UnsupportedOperationException so the file will be send using usual write(AbstractIoSession, IoBuffer, int) call.

Parameters:

session - the session to write

region - the file region to write

length - the length of the portion to send

Returns:

the number of written bytes

Throws:

Exception - any exception thrown by the underlying system calls

add

public final void add(S session)

Adds the specified session to the I/O processor so that the I/O processor starts to perform any I/O operations related with the session.

Specified by:

add in interface IoProcessor<S extends AbstractIoSession>

Parameters:

session - The added session

remove

public final void remove(S session)

Removes and closes the specified session from the I/O processor so that the I/O processor closes the connection associated with the session and releases any other related resources.

Specified by:

remove in interface IoProcessor<S extends AbstractIoSession>

Parameters:

session - The session to be removed

write

public void write(S session,
                  WriteRequest writeRequest)

Writes the WriteRequest for the specified session.

Specified by:

write in interface IoProcessor<S extends AbstractIoSession>

Parameters:

session - The session we want the message to be written

writeRequest - the WriteRequest to write

flush

public final void flush(S session)

Flushes the internal write request queue of the specified session.

Specified by:

flush in interface IoProcessor<S extends AbstractIoSession>

Parameters:

session - The session we want the message to be written

updateTrafficMask

public final void updateTrafficMask(S session)

Updates the traffic mask for a given session

Parameters:

session - the session to update

registerNewSelector

protected abstract void registerNewSelector()
                                     throws IOException

In the case we are using the java select() method, this method is used to trash the buggy selector and create a new one, registring all the sockets on it.

Throws:

IOException - If we got an exception

isBrokenConnection

protected abstract boolean isBrokenConnection()
                                       throws IOException

Check that the select() has not exited immediately just because of a broken connection. In this case, this is a standard case, and we just have to loop.

Returns:

true if a connection has been brutally closed.

Throws:

IOException - If we got an exception

updateTrafficControl

public void updateTrafficControl(S session)

Controls the traffic of the specified session depending of the IoSession.isReadSuspended() and IoSession.isWriteSuspended() flags

Specified by:

updateTrafficControl in interface IoProcessor<S extends AbstractIoSession>

Parameters:

session - The session to be updated