Package org.jctools.channels.mpsc

Class MpscOffHeapFixedSizeRingBuffer

java.lang.Object

org.jctools.channels.proxy.ProxyChannelRingBuffer

org.jctools.channels.OffHeapFixedMessageSizeRingBuffer

org.jctools.channels.mpsc.MpscOffHeapFixedSizeRingBuffer

Direct Known Subclasses:

MpscChannelConsumer, MpscChannelProducer

public class MpscOffHeapFixedSizeRingBuffer
extends OffHeapFixedMessageSizeRingBuffer

Channel protocol: - Fixed message size - 'null' indicator in message preceding byte (potentially use same for type mapping in future) - Use Vyukov MPMC like algorithm relying on indicator to support in place detection of next element existence

Field Summary

Fields inherited from class org.jctools.channels.OffHeapFixedMessageSizeRingBuffer

bufferAddress, consumerIndexAddress, HEADER_SIZE, mask, MESSAGE_INDICATOR_SIZE, messageSize, producerIndexAddress, READ_ACQUIRE_INDICATOR, READ_RELEASE_INDICATOR, referenceMessageSize, references, WRITE_ACQUIRE_INDICATOR, WRITE_RELEASE_INDICATOR

Fields inherited from class org.jctools.channels.proxy.ProxyChannelRingBuffer

EOF

Constructor Summary

Constructors

Modifier	Constructor	Description
	MpscOffHeapFixedSizeRingBuffer(int capacity, int messageSize, int referenceMessageSize)
protected	MpscOffHeapFixedSizeRingBuffer(java.nio.ByteBuffer buff, int capacity, boolean isProducer, boolean isConsumer, boolean initialize, int messageSize, java.lang.Object[] references, int referenceMessageSize)	This is to be used for an IPC queue with the direct buffer used being a memory mapped file.

Method Summary

Modifier and Type	Method	Description
private boolean	casProducerIndex(long expected, long update)
protected long	readAcquire()	Acquire an offset to read from
protected void	readRelease(long offset)	Release the offset from reading
protected long	writeAcquire()	Acquire an offset to write to.
protected void	writeRelease(long offset)
protected void	writeRelease(long offset, int callTypeId)	Ordered store of the callTypeId for the message at offset

Methods inherited from class org.jctools.channels.OffHeapFixedMessageSizeRingBuffer

arrayIndexForCursor, arrayIndexForCursor, capacity, consumerReferenceArrayIndex, createReferenceArray, getRequiredArraySize, getRequiredBufferSize, isEmpty, isReadReleased, lpConsumerIndex, lpProducerIndex, lvConsumerIndex, lvProducerIndex, offsetForIndex, offsetForIndex, producerReferenceArrayIndex, readAcquireState, readReference, readReleaseState, relativeIndexForOffset, relativeIndexForOffset, size, soConsumerIndex, soProducerIndex, writeAcquireState, writeReference, writeReleaseState

Methods inherited from class java.lang.Object

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

Constructor Detail

MpscOffHeapFixedSizeRingBuffer

public MpscOffHeapFixedSizeRingBuffer(int capacity,
                                      int messageSize,
                                      int referenceMessageSize)

MpscOffHeapFixedSizeRingBuffer

protected MpscOffHeapFixedSizeRingBuffer(java.nio.ByteBuffer buff,
                                         int capacity,
                                         boolean isProducer,
                                         boolean isConsumer,
                                         boolean initialize,
                                         int messageSize,
                                         java.lang.Object[] references,
                                         int referenceMessageSize)

This is to be used for an IPC queue with the direct buffer used being a memory mapped file.

Parameters:

buff -

capacity -

Method Detail

writeAcquire

protected final long writeAcquire()

Description copied from class: ProxyChannelRingBuffer

Acquire an offset to write to. If there's no space available a wait strategy may be used.

Specified by:

writeAcquire in class OffHeapFixedMessageSizeRingBuffer

Returns:

a base address for a message acquired to be written, or EOF if none is available

writeRelease

protected final void writeRelease(long offset)

Specified by:

writeRelease in class OffHeapFixedMessageSizeRingBuffer

Parameters:

offset - the base address of a message that we are done writing and can be read now

writeRelease

protected final void writeRelease(long offset,
                                  int callTypeId)

Description copied from class: ProxyChannelRingBuffer

Ordered store of the callTypeId for the message at offset

Specified by:

writeRelease in class ProxyChannelRingBuffer

Parameters:

offset - the offset that was released for writing

callTypeId - A unique ID for the call

readAcquire

protected final long readAcquire()

Description copied from class: ProxyChannelRingBuffer

Acquire an offset to read from

Specified by:

readAcquire in class OffHeapFixedMessageSizeRingBuffer

Returns:

a base address for a message acquired to be read, or EOF if none is available

readRelease

protected final void readRelease(long offset)

Description copied from class: ProxyChannelRingBuffer

Release the offset from reading

Specified by:

readRelease in class OffHeapFixedMessageSizeRingBuffer

Parameters:

offset - the base address of a message that we are done reading and can be overwritten now

casProducerIndex

private boolean casProducerIndex(long expected,
                                 long update)