Package org.jgroups.protocols

Class RingBufferBundlerLockless

java.lang.Object

org.jgroups.protocols.BaseBundler

org.jgroups.protocols.RingBufferBundlerLockless

All Implemented Interfaces:

Bundler

public class RingBufferBundlerLockless
extends BaseBundler

Bundler which doesn't use locks but relies on CAS. There is 1 reader thread which gets unparked by (exactly one) writer when the max size has been exceeded, or no other threads are sending messages.

Since:

4.0

Author:

Bela Ban

Field Summary

Fields

Modifier and Type	Field	Description
protected java.util.concurrent.atomic.AtomicLong	accumulated_bytes
protected Message[]	buf
protected Runner	bundler_thread
protected java.util.concurrent.atomic.AtomicInteger	num_threads
protected int	read_index
protected java.lang.Runnable	run_function
protected java.util.concurrent.atomic.AtomicInteger	size
protected static java.lang.String	THREAD_NAME
protected java.util.concurrent.atomic.AtomicInteger	tmp_write_index
protected java.util.concurrent.atomic.AtomicBoolean	unparking
protected int	write_index
protected java.util.concurrent.atomic.AtomicInteger	write_permits

Fields inherited from class org.jgroups.protocols.BaseBundler

count, lock, log, msgs, output, transport

Constructor Summary

Constructors

Constructor	Description
RingBufferBundlerLockless()
RingBufferBundlerLockless(int capacity)

Method Summary

Modifier and Type	Method	Description
int	_readMessages()
protected int	advanceWriteIndex()
protected static int	assertPositive(int value, java.lang.String message)
protected int	getPermitToWrite()
int	getQueueSize()	If the bundler has a queue and it should be managed by a queuing discipline (like Random Early Detection), then return the number of elements in the queue, else -1.
protected int	getWriteIndex()
protected int	increment(int index)
protected int	index(int idx)
void	init(TP transport)	Called after creation of the bundler
protected int	marshalMessagesToSameDestination(Address dest, Message[] buf, int start_index, int available_msgs, int max_bundle_size)
int	readIndex()
protected void	readMessages()
void	reset()
void	send(Message msg)
protected int	sendBundledMessages(Message[] buf, int read_index, int available_msgs)	Read and send messages in range [read-index ..
int	size()	Returns the total number of messages in the hashmap
void	start()	Called after Bundler.init(TP)
void	stop()
java.lang.String	toString()
int	writeIndex()

Methods inherited from class org.jgroups.protocols.BaseBundler

addMessage, clearMessages, sendBundledMessages, sendMessageList, sendSingleMessage, viewChange

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jgroups.protocols.Bundler

getStats, resetStats

Field Detail

buf

protected Message[] buf

read_index

protected int read_index

write_index

protected volatile int write_index

tmp_write_index

protected final java.util.concurrent.atomic.AtomicInteger tmp_write_index

write_permits

protected final java.util.concurrent.atomic.AtomicInteger write_permits

size

protected final java.util.concurrent.atomic.AtomicInteger size

num_threads

protected final java.util.concurrent.atomic.AtomicInteger num_threads

accumulated_bytes

protected final java.util.concurrent.atomic.AtomicLong accumulated_bytes

unparking

protected final java.util.concurrent.atomic.AtomicBoolean unparking

bundler_thread

protected Runner bundler_thread

THREAD_NAME

protected static final java.lang.String THREAD_NAME

See Also:

Constant Field Values

run_function

protected final java.lang.Runnable run_function

Constructor Detail

RingBufferBundlerLockless

public RingBufferBundlerLockless()

RingBufferBundlerLockless

public RingBufferBundlerLockless(int capacity)

Method Detail

readIndex

public int readIndex()

writeIndex

public int writeIndex()

size

public int size()

Description copied from class: BaseBundler

Returns the total number of messages in the hashmap

Specified by:

size in interface Bundler

Overrides:

size in class BaseBundler

getQueueSize

public int getQueueSize()

Description copied from interface: Bundler

If the bundler has a queue and it should be managed by a queuing discipline (like Random Early Detection), then return the number of elements in the queue, else -1. In the latter case, the queue won't be managed.
This method needs to be fast as it might get called on every message to be sent.

init

public void init(TP transport)

Description copied from interface: Bundler

Called after creation of the bundler

Specified by:

init in interface Bundler

Overrides:

init in class BaseBundler

Parameters:

transport - the transport, for further reference

reset

public void reset()

start

public void start()

Description copied from interface: Bundler

Called after Bundler.init(TP)

Specified by:

start in interface Bundler

Overrides:

start in class BaseBundler

stop

public void stop()

Specified by:

stop in interface Bundler

Overrides:

stop in class BaseBundler

send

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

Specified by:

send in interface Bundler

Overrides:

send in class BaseBundler

Throws:

java.lang.Exception

getWriteIndex

protected int getWriteIndex()

getPermitToWrite

protected int getPermitToWrite()

advanceWriteIndex

protected int advanceWriteIndex()

readMessages

protected void readMessages()

sendBundledMessages

protected int sendBundledMessages(Message[] buf,
                                  int read_index,
                                  int available_msgs)

Read and send messages in range [read-index .. read-index+available_msgs-1]

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

_readMessages

public int _readMessages()

marshalMessagesToSameDestination

protected int marshalMessagesToSameDestination(Address dest,
                                               Message[] buf,
                                               int start_index,
                                               int available_msgs,
                                               int max_bundle_size)
                                        throws java.lang.Exception

Throws:

java.lang.Exception

increment

protected final int increment(int index)

index

protected final int index(int idx)

assertPositive

protected static int assertPositive(int value,
                                    java.lang.String message)