com.hazelcast.internal.networking.nio

Class NioEventLoopGroup

java.lang.Object

com.hazelcast.internal.networking.nio.NioEventLoopGroup

All Implemented Interfaces:

EventLoopGroup

public class NioEventLoopGroup
extends Object
implements EventLoopGroup

A non blocking EventLoopGroup implementation that makes use of Selector to have a limited set of io threads, handle an arbitrary number of connections. Each NioChannel has 2 parts:

1. NioChannelReader: triggered by the NioThread when data is available in the socket. The NioChannelReader takes care of reading data from the socket and calling the appropriate ChannelInboundHandler
2. NioChannelWriter: triggered by the NioThread when either space is available in the socket for writing, or when there is something that needs to be written e.g. a Packet. The NioChannelWriter takes care of calling the appropriate ChannelOutboundHandler to convert the OutboundFrame to bytes in in the ByteBuffer and writing it to the socket.

By default the NioThread blocks on the Selector, but it can be put in a 'selectNow' mode that makes it spinning on the selector. This is an experimental feature and will cause the io threads to run hot. For this reason, when this feature is enabled, the number of io threads should be reduced (preferably 1).

Constructor Summary

Constructors

Constructor and Description
NioEventLoopGroup(LoggingService loggingService, MetricsRegistry metricsRegistry, String hzName, ChannelErrorHandler errorHandler, int inputThreadCount, int outputThreadCount, int balanceIntervalSeconds, ChannelInitializer channelInitializer)

Method Summary

Modifier and Type	Method and Description
NioThread[]	getInputThreads()
IOBalancer	getIOBalancer()
NioThread[]	getOutputThreads()
void	register(Channel channel) Registers a channel at this EventLoopGroup.
void	setSelectorMode(SelectorMode mode)
void	shutdown() Shuts down this EventLoopGroup.
void	start() Starts this EventLoopGroup.

Methods inherited from class java.lang.Object

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

Constructor Detail

NioEventLoopGroup

public NioEventLoopGroup(LoggingService loggingService,
                         MetricsRegistry metricsRegistry,
                         String hzName,
                         ChannelErrorHandler errorHandler,
                         int inputThreadCount,
                         int outputThreadCount,
                         int balanceIntervalSeconds,
                         ChannelInitializer channelInitializer)

Method Detail

setSelectorMode

public void setSelectorMode(SelectorMode mode)

getInputThreads

public NioThread[] getInputThreads()

getOutputThreads

public NioThread[] getOutputThreads()

getIOBalancer

public IOBalancer getIOBalancer()

start

public void start()

Description copied from interface: EventLoopGroup

Starts this EventLoopGroup.

Specified by:

start in interface EventLoopGroup

shutdown

public void shutdown()

Description copied from interface: EventLoopGroup

Shuts down this EventLoopGroup.

Specified by:

shutdown in interface EventLoopGroup

register

public void register(Channel channel)

Description copied from interface: EventLoopGroup

Registers a channel at this EventLoopGroup. Every Channel should be registered at at most 1 EventLoopGroup and it is very unlikely that during the lifespan of the Channel, it will change its EventLoopGroup.

Specified by:

register in interface EventLoopGroup

Parameters:

channel - the channel to register.