org.jgroups.stack
Class ProtocolStack

java.lang.Object
  org.jgroups.stack.Protocol
      org.jgroups.stack.ProtocolStack

All Implemented Interfaces:

Transport

public class ProtocolStack
extends Protocol
implements Transport

A ProtocolStack manages a number of protocols layered above each other. It creates all protocol classes, initializes them and, when ready, starts all of them, beginning with the bottom most protocol. It also dispatches messages received from the stack to registered objects (e.g. channel, GMP) and sends messages sent by those objects down the stack.

The ProtocolStack makes use of the Configurator to setup and initialize stacks, and to destroy them again when not needed anymore

Version:

$Id: ProtocolStack.java,v 1.59 2007/11/06 17:13:51 vlada Exp $

Author:

Bela Ban

Field Summary

static int	ABOVE
static int	BELOW
protected org.jgroups.stack.ProtocolStack.PatternedThreadFactory	thread_factory
TimeScheduler	timer
protected org.jgroups.stack.ProtocolStack.PatternedThreadFactory	timer_thread_factory

Fields inherited from class org.jgroups.stack.Protocol

down_prot, log, props, stack, stats, up_prot

Constructor Summary

ProtocolStack()
Only used by Simulator; don't use

ProtocolStack(JChannel channel, java.lang.String setup_string)

ProtocolStack(ThreadFactory factory, JChannel channel, java.lang.String setup_string)

Method Summary

Protocol	createProtocol(java.lang.String prot_spec) Creates a new protocol given the protocol specification.
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.
java.util.Map<java.lang.String,java.lang.Object>	dumpStats()
java.lang.String	dumpTimerQueue()
Protocol	findProtocol(java.lang.String name) Returns a given protocol or null if not found
void	flushEvents() Deprecated.
Channel	getChannel()
java.util.Map<java.lang.Thread,java.util.concurrent.locks.ReentrantLock>	getLocks()
java.lang.String	getName()
java.util.Vector<Protocol>	getProtocols() Returns all protocols in a list, from top to bottom.
ThreadFactory	getThreadFactory()
int	getTimerThreads()
Protocol	getTransport() Returns the bottom most protocol
void	insertProtocol(Protocol prot, int position, java.lang.String neighbor_prot) Inserts an already created (and initialized) protocol into the protocol list.
static ThreadFactory	newThreadFactory(java.lang.ThreadGroup group, java.lang.String baseName, boolean createDaemons)
static ThreadFactory	newThreadFactory(ThreadNamingPattern pattern, java.lang.ThreadGroup group, java.lang.String baseName, boolean createDaemons)
java.lang.String	printProtocolSpec(boolean include_properties) Prints the names of the protocols, from the bottom to top.
java.lang.String	printProtocolSpecAsXML()
java.lang.Object	receive(long timeout)
Protocol	removeProtocol(java.lang.String prot_name) Removes a protocol from the stack.
void	send(Message msg)
void	setup()
void	startStack() Start all layers.
void	stopStack() 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.

Methods inherited from class org.jgroups.stack.Protocol

downThreadEnabled, enableStats, getDownProtocol, getProperties, getProtocolStack, getUpProtocol, init, printStats, providedDownServices, providedUpServices, requiredDownServices, requiredUpServices, resetStats, setDownProtocol, setProperties, setPropertiesInternal, setProtocolStack, setUpProtocol, start, statsEnabled, stop, upThreadEnabled

Methods inherited from class java.lang.Object

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

Field Detail

ABOVE

public static final int ABOVE

See Also:

Constant Field Values

BELOW

public static final int BELOW

See Also:

Constant Field Values

thread_factory

protected final org.jgroups.stack.ProtocolStack.PatternedThreadFactory thread_factory

timer_thread_factory

protected final org.jgroups.stack.ProtocolStack.PatternedThreadFactory timer_thread_factory

timer

public final TimeScheduler timer

Constructor Detail

ProtocolStack

public ProtocolStack(JChannel channel,
                     java.lang.String setup_string)
              throws ChannelException

Throws:

ChannelException

ProtocolStack

public ProtocolStack(ThreadFactory factory,
                     JChannel channel,
                     java.lang.String setup_string)
              throws ChannelException

Throws:

ChannelException

ProtocolStack

public ProtocolStack()
              throws ChannelException

Only used by Simulator; don't use

Throws:

ChannelException

Method Detail

getThreadFactory

public ThreadFactory getThreadFactory()

getLocks

public java.util.Map<java.lang.Thread,java.util.concurrent.locks.ReentrantLock> getLocks()

getChannel

public Channel getChannel()

getTimerThreads

public int getTimerThreads()

getProtocols

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

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

getTransport

public Protocol getTransport()

Returns the bottom most protocol

dumpStats

public java.util.Map<java.lang.String,java.lang.Object> dumpStats()

Overrides:

dumpStats in class Protocol

Returns:

Map>

dumpTimerQueue

public java.lang.String dumpTimerQueue()

printProtocolSpec

public java.lang.String printProtocolSpec(boolean include_properties)

Prints the names of the protocols, from the bottom to top. If include_properties is true, the properties for each protocol will also be printed.

printProtocolSpecAsXML

public java.lang.String printProtocolSpecAsXML()

setup

public void setup()
           throws java.lang.Exception

Throws:

java.lang.Exception

createProtocol

public Protocol createProtocol(java.lang.String prot_spec)
                        throws java.lang.Exception

Creates a new protocol given the protocol specification.

Parameters:

prot_spec - The specification of the protocol. Same convention as for specifying a protocol stack. An exception will be thrown if the class cannot be created. Example:

"VERIFY_SUSPECT(timeout=1500)"

Note that no colons (:) have to be specified

Returns:

Protocol The newly created protocol

Throws:

java.lang.Exception - Will be thrown when the new protocol cannot be created

insertProtocol

public void insertProtocol(Protocol prot,
                           int position,
                           java.lang.String neighbor_prot)
                    throws java.lang.Exception

Inserts an already created (and initialized) protocol into the protocol list. Sets the links to the protocols above and below correctly and adjusts the linked list of protocols accordingly. Note that this method may change the value of top_prot or bottom_prot.

Parameters:

prot - The protocol to be inserted. Before insertion, a sanity check will ensure that none of the existing protocols have the same name as the new protocol.

position - Where to place the protocol with respect to the neighbor_prot (ABOVE, BELOW)

neighbor_prot - The name of the neighbor protocol. An exception will be thrown if this name is not found

Throws:

java.lang.Exception - Will be thrown when the new protocol cannot be created, or inserted.

removeProtocol

public Protocol removeProtocol(java.lang.String prot_name)
                        throws java.lang.Exception

Removes a protocol from the stack. Stops the protocol and readjusts the linked lists of protocols.

Parameters:

prot_name - The name of the protocol. Since all protocol names in a stack have to be unique (otherwise the stack won't be created), the name refers to just 1 protocol.

Throws:

java.lang.Exception - Thrown if the protocol cannot be stopped correctly.

findProtocol

public Protocol findProtocol(java.lang.String name)

Returns a given protocol or null if not found

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 Protocol

startStack

public void startStack()
                throws java.lang.Exception

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

Throws:

java.lang.Exception

stopStack

public void stopStack()

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

flushEvents

public void flushEvents()

Deprecated.

Not needed anymore, just left in here for backwards compatibility with JBoss AS

send

public void send(Message msg)
          throws java.lang.Exception

Specified by:

send in interface Transport

Throws:

java.lang.Exception

receive

public java.lang.Object receive(long timeout)
                         throws java.lang.Exception

Specified by:

receive in interface Transport

Throws:

java.lang.Exception

getName

public java.lang.String getName()

Specified by:

getName in class Protocol

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 Protocol

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 Protocol

newThreadFactory

public static ThreadFactory newThreadFactory(java.lang.ThreadGroup group,
                                             java.lang.String baseName,
                                             boolean createDaemons)

newThreadFactory

public static ThreadFactory newThreadFactory(ThreadNamingPattern pattern,
                                             java.lang.ThreadGroup group,
                                             java.lang.String baseName,
                                             boolean createDaemons)