org.mortbay.jetty.nio
Class SelectChannelConnector

java.lang.Object
  org.mortbay.component.AbstractLifeCycle
      org.mortbay.jetty.AbstractBuffers
          org.mortbay.jetty.AbstractConnector
              org.mortbay.jetty.nio.AbstractNIOConnector
                  org.mortbay.jetty.nio.SelectChannelConnector

All Implemented Interfaces:

LifeCycle, Buffers, Connector, NIOConnector

public class SelectChannelConnector
extends AbstractNIOConnector

Selecting NIO connector.

This connector uses efficient NIO buffers with a non blocking threading model. Direct NIO buffers are used and threads are only allocated to connections with requests. Synchronization is used to simulate blocking for the servlet API, and any unflushed content at the end of request handling is written asynchronously.

This connector is best used when there are a many connections that have idle periods.

When used with Continuation, threadless waits are supported. When a filter or servlet calls getEvent on a Continuation, a RetryRequest runtime exception is thrown to allow the thread to exit the current request handling. Jetty will catch this exception and will not send a response to the client. Instead the thread is released and the Continuation is placed on the timer queue. If the Continuation timeout expires, or it's resume method is called, then the request is again allocated a thread and the request is retried. The limitation of this approach is that request content is not available on the retried request, thus if possible it should be read after the continuation or saved as a request attribute or as the associated object of the Continuation instance.

Author:

gregw

Nested Class Summary

static class	SelectChannelConnector.ConnectorEndPoint
static class	SelectChannelConnector.RetryContinuation

Field Summary

Fields inherited from class org.mortbay.jetty.AbstractConnector

_lowResourceMaxIdleTime, _maxIdleTime, _soLingerTime

Fields inherited from class org.mortbay.jetty.AbstractBuffers

_loss, BUFFER_LOSS_RATE

Constructor Summary

SelectChannelConnector()
Constructor.

Method Summary

void	accept(int acceptorID)
void	close()
void	customize(EndPoint endpoint, Request request) Customize a request for an endpoint.
protected void	doStart()
protected void	doStop()
Object	getConnection()
boolean	getDelaySelectKeyUpdate() Get delay select key update If true, the select set is not updated when a endpoint is dispatched for reading.
int	getLocalPort()
long	getLowResourcesConnections()
long	getLowResourcesMaxIdleTime()
protected Connection	newConnection(SocketChannel channel, SelectChannelEndPoint endpoint)
Continuation	newContinuation()
protected SelectChannelEndPoint	newEndPoint(SocketChannel channel, SelectorManager.SelectSet selectSet, SelectionKey key)
void	open() Opens the connector
void	persist(EndPoint endpoint) Persist an endpoint.
void	setDelaySelectKeyUpdate(boolean delay)
void	setLowResourceMaxIdleTime(int lowResourcesMaxIdleTime) Set the period in ms that a connection is allowed to be idle when this there are more than getLowResourcesConnections() connections.
void	setLowResourcesConnections(long lowResourcesConnections) Set the number of connections, which if exceeded places this manager in low resources state.
void	setLowResourcesMaxIdleTime(long lowResourcesMaxIdleTime) Deprecated. use setLowResourceMaxIdleTime(int)
void	setMaxIdleTime(int maxIdleTime)
void	stopAccept(int acceptorID)

Methods inherited from class org.mortbay.jetty.nio.AbstractNIOConnector

getUseDirectBuffers, newBuffer, setUseDirectBuffers

Methods inherited from class org.mortbay.jetty.AbstractConnector

configure, connectionClosed, connectionOpened, getAcceptorPriorityOffset, getAcceptors, getAcceptQueueSize, getConfidentialPort, getConfidentialScheme, getConnections, getConnectionsDurationAve, getConnectionsDurationMax, getConnectionsDurationMin, getConnectionsDurationTotal, getConnectionsOpen, getConnectionsOpenMax, getConnectionsOpenMin, getConnectionsRequestsAve, getConnectionsRequestsMax, getConnectionsRequestsMin, getHost, getIntegralPort, getIntegralScheme, getLowResourceMaxIdleTime, getMaxIdleTime, getName, getPort, getRequests, getResolveNames, getServer, getSoLingerTime, getStatsOn, getStatsOnMs, getThreadPool, isConfidential, isIntegral, join, setAcceptorPriorityOffset, setAcceptors, setAcceptQueueSize, setConfidentialPort, setConfidentialScheme, setHost, setIntegralPort, setIntegralScheme, setName, setPort, setResolveNames, setServer, setSoLingerTime, setStatsOn, setThreadPool, statsReset, toString

Methods inherited from class org.mortbay.jetty.AbstractBuffers

getBuffer, getHeaderBufferSize, getRequestBufferSize, getResponseBufferSize, returnBuffer, setHeaderBufferSize, setRequestBufferSize, setResponseBufferSize

Methods inherited from class org.mortbay.component.AbstractLifeCycle

isFailed, isRunning, isStarted, isStarting, isStopped, isStopping, start, stop

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.mortbay.jetty.Connector

getHeaderBufferSize, getRequestBufferSize, getResponseBufferSize, setHeaderBufferSize, setRequestBufferSize, setResponseBufferSize

Methods inherited from interface org.mortbay.component.LifeCycle

isFailed, isRunning, isStarted, isStarting, isStopped, isStopping, start, stop

Methods inherited from interface org.mortbay.io.Buffers

getBuffer, returnBuffer

Constructor Detail

SelectChannelConnector

public SelectChannelConnector()

Constructor.

Method Detail

accept

public void accept(int acceptorID)
            throws IOException

Specified by:

accept in class AbstractConnector

Throws:

IOException

stopAccept

public void stopAccept(int acceptorID)
                throws Exception

Overrides:

stopAccept in class AbstractConnector

Throws:

Exception

close

public void close()
           throws IOException

Throws:

IOException

customize

public void customize(EndPoint endpoint,
                      Request request)
               throws IOException

Description copied from interface: Connector

Customize a request for an endpoint. Called on every request to allow customization of the request for the particular endpoint (eg security properties from a SSL connection).

Specified by:

customize in interface Connector

Overrides:

customize in class AbstractConnector

Throws:

IOException

persist

public void persist(EndPoint endpoint)
             throws IOException

Description copied from interface: Connector

Persist an endpoint. Called after every request if the connection is to remain open.

Specified by:

persist in interface Connector

Overrides:

persist in class AbstractConnector

Throws:

IOException

getConnection

public Object getConnection()

Returns:

the underlying socket, channel, buffer etc. for the connector.

getDelaySelectKeyUpdate

public boolean getDelaySelectKeyUpdate()

Get delay select key update If true, the select set is not updated when a endpoint is dispatched for reading. The assumption is that the task will be short and thus will probably be complete before the select is tried again.

Returns:

Returns the assumeShortDispatch.

getLocalPort

public int getLocalPort()

Returns:

The actual port the connector is listening on or -1 if there is no port or the connector is not open.

newContinuation

public Continuation newContinuation()

Specified by:

newContinuation in interface Connector

Overrides:

newContinuation in class AbstractConnector

open

public void open()
          throws IOException

Description copied from interface: Connector

Opens the connector

Throws:

IOException

setDelaySelectKeyUpdate

public void setDelaySelectKeyUpdate(boolean delay)

Parameters:

delay - If true, updating a SelectionKey is delayed until a redundant event is schedules. This is an optimization that assumes event handling can be completed before the next select completes.

setMaxIdleTime

public void setMaxIdleTime(int maxIdleTime)

Specified by:

setMaxIdleTime in interface Connector

Overrides:

setMaxIdleTime in class AbstractConnector

Parameters:

maxIdleTime - The maxIdleTime to set.

getLowResourcesConnections

public long getLowResourcesConnections()

Returns:

the lowResourcesConnections

setLowResourcesConnections

public void setLowResourcesConnections(long lowResourcesConnections)

Set the number of connections, which if exceeded places this manager in low resources state. This is not an exact measure as the connection count is averaged over the select sets.

Parameters:

lowResourcesConnections - the number of connections

See Also:

#setLowResourcesMaxIdleTime(long)}

getLowResourcesMaxIdleTime

public long getLowResourcesMaxIdleTime()

Returns:

the lowResourcesMaxIdleTime

setLowResourcesMaxIdleTime

public void setLowResourcesMaxIdleTime(long lowResourcesMaxIdleTime)

Deprecated. use setLowResourceMaxIdleTime(int)

Set the period in ms that a connection is allowed to be idle when this there are more than getLowResourcesConnections() connections. This allows the server to rapidly close idle connections in order to gracefully handle high load situations.

Parameters:

lowResourcesMaxIdleTime - the period in ms that a connection is allowed to be idle when resources are low.

See Also:

#setMaxIdleTime(long)}

setLowResourceMaxIdleTime

public void setLowResourceMaxIdleTime(int lowResourcesMaxIdleTime)

Set the period in ms that a connection is allowed to be idle when this there are more than getLowResourcesConnections() connections. This allows the server to rapidly close idle connections in order to gracefully handle high load situations.

Specified by:

setLowResourceMaxIdleTime in interface Connector

Overrides:

setLowResourceMaxIdleTime in class AbstractConnector

Parameters:

lowResourcesMaxIdleTime - the period in ms that a connection is allowed to be idle when resources are low.

See Also:

#setMaxIdleTime(long)}

doStart

protected void doStart()
                throws Exception

Overrides:

doStart in class AbstractConnector

Throws:

Exception

doStop

protected void doStop()
               throws Exception

Overrides:

doStop in class AbstractConnector

Throws:

Exception

newEndPoint

protected SelectChannelEndPoint newEndPoint(SocketChannel channel,
                                            SelectorManager.SelectSet selectSet,
                                            SelectionKey key)
                                     throws IOException

Throws:

IOException

newConnection

protected Connection newConnection(SocketChannel channel,
                                   SelectChannelEndPoint endpoint)