High Performance(2)Ringbuffer and Disruptor

High Performance(2)Ringbuffer and Disruptor

1. Disruptor Introduction
a set circle array, lock-free ring buffer
Component - Ringbuffer
current number % size = order number   12%10=2 
the end of the array is managed by consumer.

Component - Sequence
thread safe, counter

Component - SequenceBarrier
consumers wait for sequence

Component - WaitStrategy
BusySpinWaitStrategy, BlockingWaitStrategy, SleepingWaitStrategy, YieldingWaitStragegy
PhasedBackoffWaitStrategy

BactchEventProcessor
consumer

WorkProcessor
consumers share one sequence

WorkerPool
All the WorkProcessor which share the same Sequence are managed by WorkerPool

2. Simple Producer and Consumer
All the example codes are in easydisruptor.
dependencies
libraryDependencies ++= Seq(
    "org.scalatest"       %   "scalatest_2.10"            % "1.9.1"   % "test",
    "org.specs2"          %%  "specs2"                    % "1.13"    % "test",
    "com.lmax"            %   "disruptor"                 % "3.3.0"
)

model
package com.sillycat.easydisruptor.model
class LongEvent(){
  var value = Long.MinValue
}
factory
package com.sillycat.easydisruptor.factory
import com.lmax.disruptor.EventFactory
import com.sillycat.easydisruptor.model.LongEvent

class LongEventFactory extends EventFactory[LongEvent] {
  def  newInstance():LongEvent = {
    return new LongEvent()
  }
}

translator
package com.sillycat.easydisruptor.translator

import com.sillycat.easydisruptor.model.LongEvent
import java.nio.ByteBuffer
import com.lmax.disruptor.EventTranslatorOneArg;

class CustomEventTranslatorOneArg extends EventTranslatorOneArg[LongEvent,ByteBuffer]{

  def translateTo(event: LongEvent, sequence: Long, bb: ByteBuffer) = {
    event.value = bb.getLong(0)
  }

}

consumer
package com.sillycat.easydisruptor.consumer

import com.lmax.disruptor.EventHandler
import com.sillycat.easydisruptor.model.LongEvent

class LongEventHandler extends EventHandler[LongEvent]{

  def onEvent(event:LongEvent,sequence:Long,endOfBatch:Boolean): Unit ={
    println("Event: " + event.value)
  }

}

producer
package com.sillycat.easydisruptor.producer

import com.lmax.disruptor.RingBuffer
import java.nio.ByteBuffer
import com.sillycat.easydisruptor.translator.CustomEventTranslatorOneArg
import com.sillycat.easydisruptor.model.LongEvent

class LongEventProducer(ringBuffer: RingBuffer[LongEvent]) {
  val translator = new CustomEventTranslatorOneArg()
  def onData(bb:ByteBuffer) = {
    ringBuffer.publishEvent(translator,bb)
  }
}

App to run
package com.sillycat.easydisruptor

import java.util.concurrent.Executors
import com.sillycat.easydisruptor.factory.LongEventFactory
import com.lmax.disruptor.dsl.Disruptor
import com.sillycat.easydisruptor.consumer.LongEventHandler
import com.sillycat.easydisruptor.producer.LongEventProducer
import java.nio.ByteBuffer

object LongEventApp extends App{
  val executor = Executors.newCachedThreadPool()
  val factory = new LongEventFactory()

  // Specify the size of the ring buffer, must be power of 2.
  val bufferSize = 1024

  val disruptor = new Disruptor(factory, bufferSize, executor)
  //set consumer/handler
  disruptor.handleEventsWith(new LongEventHandler())
  disruptor.start()

  val ringBuffer = disruptor.getRingBuffer()
  val producer = new LongEventProducer(ringBuffer)

  val bb = ByteBuffer.allocate(8);
  for( a <- 1 to 10){
    bb.putLong(0, a)
    producer.onData(bb)
    Thread.sleep(1000)
  }
  sys.exit(0)
}

We can also define the Disruptor as follow:
val disruptor = new Disruptor[LongEvent](factory, bufferSize, executor,ProducerType.SINGLE, new SleepingWaitStrategy())


References:
http://developer.51cto.com/art/201306/399341.htm
http://liuxun.org/blog/disruptor-yi-ge-kai-yuan-de-gao-xiao-nei-cun-wu-suo-dui-lie/
http://ziyue1987.github.io/pages/2013/09/22/disruptor-use-manual.html

http://lmax-exchange.github.io/disruptor/

More Example
https://code.google.com/p/disruptor/source/browse/trunk/code/src/perf/?r=421#perf%2Fcom%2Flmax%2Fdisruptor