edu.umass.cs.nio

Class AbstractPacketDemultiplexer<MessageType>

java.lang.Object

edu.umass.cs.nio.AbstractPacketDemultiplexer<MessageType>

Type Parameters:

MessageType - Indicates the generic type of messages processed by this demultiplexer.

All Implemented Interfaces:

PacketDemultiplexer<MessageType>

Direct Known Subclasses:

AbstractJSONPacketDemultiplexer, PaxosPacketDemultiplexer, PaxosPacketDemultiplexerFast, ReconfigurationPacketDemultiplexer

public abstract class AbstractPacketDemultiplexer<MessageType>
extends java.lang.Object
implements PacketDemultiplexer<MessageType>

Author:

V. Arun

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	AbstractPacketDemultiplexer.Tasker

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_THREAD_POOL_SIZE The default thread pool size.
protected static java.util.logging.Logger	log

Constructor Summary

Constructors

Constructor and Description
AbstractPacketDemultiplexer()
AbstractPacketDemultiplexer(int threadPoolSize)

Method Summary

Modifier and Type	Method and Description
static void	emulateDelays() Turns on delay emulation.
static java.lang.String	getHandleMessageReport(long threshold)
protected abstract java.lang.Integer	getPacketType(MessageType message)
protected static int	getThreadPoolSize()
protected boolean	handleMessageSuper(byte[] msg, NIOHeader header)
protected boolean	isCongested(NIOHeader header)
boolean	isOrderPreserving(MessageType msg)
protected boolean	loopback(java.lang.Object obj)
protected abstract boolean	matchesType(java.lang.Object message)
protected abstract MessageType	processHeader(byte[] message, NIOHeader header)
void	register(IntegerPacketType type) Registers type with this.
void	register(IntegerPacketType[] types) Registers types with this.
void	register(IntegerPacketType[] types, PacketDemultiplexer<MessageType> pd) Registers types with this.
void	register(IntegerPacketType type, PacketDemultiplexer<MessageType> pd) Registers type with pd.
void	register(java.util.Set<IntegerPacketType> types) Registers types with this.
void	register(java.util.Set<IntegerPacketType> types, PacketDemultiplexer<MessageType> pd) Registers types with pd;
void	registerOrderPreserving(IntegerPacketType type)
AbstractPacketDemultiplexer<MessageType>	setNumDemultiplexerThreads(int corePoolSize) Sets the number of packet demultiplexing threads.
protected AbstractPacketDemultiplexer<MessageType>	setThreadName(java.lang.String name)
static void	setThreadPoolSize(int threadPoolSize)
void	stop() Any created instance of AbstractPacketDemultiplexer or its inheritors must be cleanly closed by invoking this stop method.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.umass.cs.nio.interfaces.PacketDemultiplexer

handleMessage

Field Detail

DEFAULT_THREAD_POOL_SIZE

public static final int DEFAULT_THREAD_POOL_SIZE

The default thread pool size. FIXME: Unclear what a good value is.

See Also:

Constant Field Values

log

protected static final java.util.logging.Logger log

Constructor Detail

AbstractPacketDemultiplexer

public AbstractPacketDemultiplexer(int threadPoolSize)

Parameters:

threadPoolSize - Refer documentation for setThreadPoolsize(int).

AbstractPacketDemultiplexer

public AbstractPacketDemultiplexer()

Method Detail

setThreadPoolSize

public static void setThreadPoolSize(int threadPoolSize)

Parameters:

threadPoolSize - The threadPoolSize parameter determines the level of parallelism in NIO packet processing. Setting it to 0 means no parallelism, i.e., each received packet will be fully processed by NIO before it does anything else. So if the PacketDemultiplexer.handleMessage(Object,NIOHeader) implementation blocks, NIO may deadlock. Setting the threadPoolSize higher allows PacketDemultiplexer.handleMessage(Object,NIOHeader) to include a limited number of blocking operations, but NIO can still deadlock if the number of pending PacketDemultiplexer.handleMessage(Object,NIOHeader) invocations at a node exceeds the thread pool size in this class. Thus, it is best for PacketDemultiplexer.handleMessage(Object,NIOHeader) methods to only perform operations that return quickly; if longer packet processing is needed, PacketDemultiplexer.handleMessage(Object,NIOHeader) must accordingly spawn its own helper threads. It is a bad idea, for example, for PacketDemultiplexer.handleMessage(Object,NIOHeader) to itself send a request over the network and wait until it gets back a response.

getThreadPoolSize

protected static int getThreadPoolSize()

getPacketType

protected abstract java.lang.Integer getPacketType(MessageType message)

processHeader

protected abstract MessageType processHeader(byte[] message,
                                             NIOHeader header)

matchesType

protected abstract boolean matchesType(java.lang.Object message)

setNumDemultiplexerThreads

public AbstractPacketDemultiplexer<MessageType> setNumDemultiplexerThreads(int corePoolSize)

Sets the number of packet demultiplexing threads.

Parameters:

corePoolSize -

Returns:

this

setThreadName

protected AbstractPacketDemultiplexer<MessageType> setThreadName(java.lang.String name)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

handleMessageSuper

protected boolean handleMessageSuper(byte[] msg,
                                     NIOHeader header)
                              throws org.json.JSONException

Throws:

org.json.JSONException

emulateDelays

public static final void emulateDelays()

Turns on delay emulation. There is no way to disable, so use with care.

loopback

protected boolean loopback(java.lang.Object obj)

isOrderPreserving

public boolean isOrderPreserving(MessageType msg)

Parameters:

msg -

Returns:

True if message order is preserved.

register

public void register(IntegerPacketType type)

Registers type with this.

Parameters:

type -

register

public void register(IntegerPacketType type,
                     PacketDemultiplexer<MessageType> pd)

Registers type with pd.

Parameters:

type -

pd -

isCongested

protected boolean isCongested(NIOHeader header)

Returns:

True if congested

register

public void register(java.util.Set<IntegerPacketType> types,
                     PacketDemultiplexer<MessageType> pd)

Registers types with pd;

Parameters:

types -

pd -

register

public void register(java.util.Set<IntegerPacketType> types)

Registers types with this.

Parameters:

types -

register

public void register(IntegerPacketType[] types,
                     PacketDemultiplexer<MessageType> pd)

Registers types with this.

Parameters:

types -

pd -

register

public void register(IntegerPacketType[] types)

Registers types with this.

Parameters:

types -

registerOrderPreserving

public void registerOrderPreserving(IntegerPacketType type)

Parameters:

type -

stop

public void stop()

Any created instance of AbstractPacketDemultiplexer or its inheritors must be cleanly closed by invoking this stop method.

getHandleMessageReport

public static java.lang.String getHandleMessageReport(long threshold)

Parameters:

threshold -

Returns:

Report of message(s) taking over threshold to be handled.