org.jgroups.fork

Class ForkProtocolStack

java.lang.Object

org.jgroups.stack.Protocol

org.jgroups.stack.ProtocolStack

org.jgroups.fork.ForkProtocolStack

public class ForkProtocolStack
extends ProtocolStack

Protocol stack which maintains the mapping between fork-channel IDs and ForkChannels

Since:

3.4

Author:

Bela Ban

Nested Class Summary

Nested classes/interfaces inherited from class org.jgroups.stack.ProtocolStack

ProtocolStack.RefCounter

Field Summary

Fields

Modifier and Type	Field and Description
protected int	connects
protected java.util.concurrent.ConcurrentMap<java.lang.String,JChannel>	fork_channels
protected java.lang.String	fork_stack_id
protected int	inits
protected Address	local_addr
protected java.util.List<Protocol>	protocols
protected UnknownForkHandler	unknownForkHandler

Fields inherited from class org.jgroups.stack.ProtocolStack

ABOVE, BELOW, bottom_prot, channel, max_list_print_size, props_handler, singleton_transports, stopped, top_prot

Fields inherited from class org.jgroups.stack.Protocol

after_creation_hook, down_prot, ergonomics, id, log, name, stack, stats, up_prot

Constructor Summary

Constructors

Constructor and Description
ForkProtocolStack(UnknownForkHandler unknownForkHandler, java.util.List<Protocol> protocols, java.lang.String fork_stack_id)

Method Summary

Modifier and Type	Method and Description
void	destroy() This method is called on a Channel.close().
java.lang.Object	down(Event evt) An event is to be sent down the stack.
JChannel	get(java.lang.String fork_channel_id)
int	getConnects()
java.util.concurrent.ConcurrentMap<java.lang.String,JChannel>	getForkChannels()
int	getInits()
java.util.List<Protocol>	getProtocols() Returns all protocols in a list, from top to bottom.
ForkProtocolStack	incrInits()
void	init() Called after instance has been created (null constructor) and before protocol is started.
JChannel	putIfAbsent(java.lang.String id, JChannel fc)
void	remove(java.lang.String fork_channel_id)
void	setLocalAddress(Address addr)
void	startStack(java.lang.String cluster, Address local_addr) Start all layers.
void	stopStack(java.lang.String cluster) Iterates through all the protocols from top to bottom and does the following: Waits until all messages in the down queue have been flushed (ie., size is 0) Calls stop() on the protocol
java.lang.Object	up(Event evt) An event was received from the layer below.
void	up(MessageBatch batch) Sends up a multiple messages in a MessageBatch.

Methods inherited from class org.jgroups.stack.ProtocolStack

addProtocol, addProtocols, addProtocols, bottomProtocol, callAfterCreationHook, copyProtocols, createProtocol, dumpStats, dumpStats, dumpStats, findProtocol, findProtocol, findProtocol, getBottomProtocol, getChannel, getName, getSingletonTransports, getTopProtocol, getTransport, initProtocolStack, insertProtocol, insertProtocol, insertProtocol, insertProtocolAtTop, insertProtocolInStack, printProtocolSpec, printProtocolSpecAsPlainString, printProtocolSpecAsXML, removeProtocol, removeProtocol, removeProtocol, removeProtocol, removeProtocols, replaceProtocol, setChannel, setup, setup, topProtocol

Methods inherited from class org.jgroups.stack.Protocol

accept, afterCreationHook, enableStats, getConfigurableObjects, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getLog, getProtocolStack, getSocketFactory, getThreadFactory, getUpProtocol, getUpServices, getValue, isErgonomics, level, parse, printStats, providedDownServices, providedUpServices, requiredDownServices, requiredUpServices, resetStatistics, resetStats, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setSocketFactory, setUpProtocol, setValue, setValues, start, statsEnabled, stop

Methods inherited from class java.lang.Object

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

Field Detail

local_addr

protected Address local_addr

fork_stack_id

protected final java.lang.String fork_stack_id

fork_channels

protected final java.util.concurrent.ConcurrentMap<java.lang.String,JChannel> fork_channels

unknownForkHandler

protected final UnknownForkHandler unknownForkHandler

protocols

protected final java.util.List<Protocol> protocols

inits

protected int inits

connects

protected int connects

Constructor Detail

ForkProtocolStack

public ForkProtocolStack(UnknownForkHandler unknownForkHandler,
                         java.util.List<Protocol> protocols,
                         java.lang.String fork_stack_id)

Method Detail

getForkChannels

public java.util.concurrent.ConcurrentMap<java.lang.String,JChannel> getForkChannels()

get

public JChannel get(java.lang.String fork_channel_id)

putIfAbsent

public JChannel putIfAbsent(java.lang.String id,
                            JChannel fc)

remove

public void remove(java.lang.String fork_channel_id)

getInits

public int getInits()

getConnects

public int getConnects()

down

public java.lang.Object down(Event evt)

Description copied from class: Protocol

An event is to be sent down the stack. The layer may want to examine its type and perform some action on it, depending on the event's type. If the event is a message MSG, then the layer may need to add a header to it (or do nothing at all) before sending it down the stack using down_prot.down(). In case of a GET_ADDRESS event (which tries to retrieve the stack's address from one of the bottom layers), the layer may need to send a new response event back up the stack using up_prot.up().

Overrides:

down in class ProtocolStack

setLocalAddress

public void setLocalAddress(Address addr)

getProtocols

public java.util.List<Protocol> getProtocols()

Description copied from class: ProtocolStack

Returns all protocols in a list, from top to bottom. These are not copies of protocols, so modifications will affect the actual instances !

Overrides:

getProtocols in class ProtocolStack

incrInits

public ForkProtocolStack incrInits()

init

public void init()
          throws java.lang.Exception

Description copied from class: Protocol

Called after instance has been created (null constructor) and before protocol is started. Properties are already set. Other protocols are not yet connected and events cannot yet be sent.

Overrides:

init in class ProtocolStack

Throws:

java.lang.Exception - Thrown if protocol cannot be initialized successfully. This will cause the ProtocolStack to fail, so the channel constructor will throw an exception

startStack

public void startStack(java.lang.String cluster,
                       Address local_addr)
                throws java.lang.Exception

Description copied from class: ProtocolStack

Start all layers. The Protocol.start() method is called in each protocol, from top to bottom. Each layer can perform some initialization, e.g. create a multicast socket

Overrides:

startStack in class ProtocolStack

Throws:

java.lang.Exception

stopStack

public void stopStack(java.lang.String cluster)

Description copied from class: ProtocolStack

Iterates through all the protocols from top to bottom and does the following:

1. Waits until all messages in the down queue have been flushed (ie., size is 0)
2. Calls stop() on the protocol

Overrides:

stopStack in class ProtocolStack

destroy

public void destroy()

Description copied from class: Protocol

This method is called on a Channel.close(). Does some cleanup; after the call the VM will terminate

Overrides:

destroy in class ProtocolStack

up

public java.lang.Object up(Event evt)

Description copied from class: Protocol

An event was received from the layer below. Usually the current layer will want to examine the event type and - depending on its type - perform some computation (e.g. removing headers from a MSG event type, or updating the internal membership list when receiving a VIEW_CHANGE event). Finally the event is either a) discarded, or b) an event is sent down the stack using down_prot.down() or c) the event (or another event) is sent up the stack using up_prot.up().

Overrides:

up in class ProtocolStack

up

public void up(MessageBatch batch)

Description copied from class: Protocol

Sends up a multiple messages in a MessageBatch. The sender of the batch is always the same, and so is the destination (null == multicast messages). Messages in a batch can be OOB messages, regular messages, or mixed messages, although the transport itself will create initial MessageBatches that contain only either OOB or regular messages.

The default processing below sends messages up the stack individually, based on a matching criteria (calling Protocol.accept(org.jgroups.Message)), and - if true - calls Protocol.up(org.jgroups.Event) for that message and removes the message. If the batch is not empty, it is passed up, or else it is dropped.

Subclasses should check if there are any messages destined for them (e.g. using MessageBatch.getMatchingMessages(short,boolean)), then possibly remove and process them and finally pass the batch up to the next protocol. Protocols can also modify messages in place, e.g. ENCRYPT could decrypt all encrypted messages in the batch, not remove them, and pass the batch up when done.

Overrides:

up in class ProtocolStack

Parameters:

batch - The message batch