LMAX Disruptor SPSC-每秒600万操作

Question

使用Disruptor环形缓冲区，我每秒只能执行600万次操作。我想知道我哪里出了问题。我的事件处理程序只是插入一个计数器。这是单生产者和单消费者。有人能告诉我我是否语义学本身错了。程序创建一个生产者线程添加到缓冲区。并创建一个事件处理程序来处理发布事件。每次发布事件时，eventhandler都会增加一个易失性计数器。

public class MainClass{

   public static class globalVariables
   {
        static int NUMBER_OF_ITERATIONS = 33554432; // 2 power 25     
        static int NUMBER_OF_THREADS;
        static int RING_SIZE = NUMBER_OF_ITERATIONS;
        static int WRITE_CODE = 1;

        static volatile int keep_going = 1; 
   };

   public void start_execution()
   {            
        int remainder = globalVariables.NUMBER_OF_ITERATIONS % globalVariables.NUMBER_OF_THREADS;               
        int iterations_per_thread = ( globalVariables.NUMBER_OF_ITERATIONS - remainder ) / globalVariables.NUMBER_OF_THREADS ;


      /* New Shared Object */
      final sharedObject newSharedObject = new sharedObject();


    ExecutorService exec = Executors.newFixedThreadPool(1);
      Disruptor<valueEvent> disruptor = new Disruptor<valueEvent>( valueEvent.EVENT_FACTORY, globalVariables.RING_SIZE, exec );


      /* Creating event handler whenever an item is published in the queue */

           final EventHandler<valueEvent> handler = new EventHandler<valueEvent>()
           {
              public void onEvent(final valueEvent event, final long sequence, 
                          final boolean endOfBatch) throws Exception
              {         
                 newSharedObject.shared_variable++; // increment the shared variable
              }
           };


          /* Use the above handler to handler events */
          disruptor.handleEventsWith(handler);


     /* start Disruptor */
     final RingBuffer<valueEvent> ringBuffer = disruptor.start();


     final long[] runtime = new long [globalVariables.NUMBER_OF_THREADS];
     /* Code the producer thread */
     final class ProducerThread extends Thread {
        int i;

        public ProducerThread( int i )
        {
            this.i = i;
        }

        public void run()
        {
           long idle_counter = 0;
           long count;

           System.out.println("In thread "+i );

           long startTime = System.nanoTime();

           //while( globalVariables.keep_going == 1 )
           for( int counter=0; counter<globalVariables.NUMBER_OF_ITERATIONS; counter++ )
           {
              // Publishers claim events in sequence
              long sequence = ringBuffer.next();
              valueEvent event = ringBuffer.get(sequence);

              event.setValue(globalVariables.WRITE_CODE); 

              // make the event available to EventProcessors
              ringBuffer.publish(sequence);  
           }

           long stopTime = System.nanoTime();
           runtime[i] = (stopTime - startTime)/1000; 
        }
     };

     /* ------------------------------------------------------------------------------- */     
     //final class AlarmHandler extends TimerTask {     
          /*** Implements TimerTask's abstract run method.   */
    //    @Override public void run(){
    //      globalVariables.keep_going = 0;
    //    }
   //  };

     /* ------------------------------------------------------------------------------- */
     /* Creating Producer threads */
     ProducerThread[] threads = new ProducerThread[globalVariables.NUMBER_OF_THREADS];
     for (int i = 0; i < globalVariables.NUMBER_OF_THREADS; i++) {
        threads[i] = new ProducerThread( i );
        threads[i].start();
     }

     // Waiting for the threads to finish
     for (int i = 0; i < globalVariables.NUMBER_OF_THREADS; i++) {
        try
        {
         threads[i].join();
        } catch ( InterruptedException e ) { System.out.println("hi exception :)"); }
     } 

     /* shutdown */     
     disruptor.shutdown();
     exec.shutdown();

     /* Printing Statistics */
     System.out.println( "Shared Variable: " + newSharedObject.shared_variable );
     for ( int i=0; i<globalVariables.NUMBER_OF_THREADS; i++ )
     {
         System.out.println("Runtime="+ runtime[i] + "; Operations per second = " + (globalVariables.NUMBER_OF_ITERATIONS  / runtime[i] )*1000000 +"ops/sec" );         
     }     

   }

    public static void main( String args[] )
    {
        globalVariables.NUMBER_OF_THREADS = Integer.parseInt( args[0] );    

        System.out.println( "Number of Threads = "+ globalVariables.NUMBER_OF_THREADS );

        MainClass mainObj = new MainClass();
        mainObj.start_execution();
        System.exit(0);
    }
};

这里是程序的输出

共享变量：33554432；运行时=5094139微秒；每秒操作=6000000

任何帮助都将不胜感激。

Answer 1

由于您在单个线程中运行事件处理程序，并且不共享该状态，因此您应该通过让事件处理程序在非易失性字段上工作来获得显着更好的性能（但仍然是正确的功能）。中断器确保您的处理程序一次只处理一个事件，因此您无需担心丢失增量。

如果系统中的另一个组件依赖于以特定顺序出现的该值（例如：它是一个控制值），那么您应该考虑将类似AtomicInteger的东西与lazySet一起使用[1]。

[1]http://psy-lob-saw.blogspot.com.au/2012/12/atomiclazyset-is-performance-win-for.html