Floodlight controller 线程池模型


     官方文档对于ThreadPool的描写叙述是:ThreadPool is a Floodlight module wrapper for a Java's ScheduledExecutorService.  It can be used to
have threads be run at specific times or periodically. 所以仅仅要对并发编程有点基础,就非常easy理解。它实现了俩接口:1)IThreadPoolService规范的是得到ScheduledExecutorService的方法,2)IFloodlightModule则是将实现类作为模块来管理(默认启动)。优点是方便其它模块非常easy的指明依赖。看代码就非常easy明确。

public interface IThreadPoolService extends IFloodlightService
{
    /**
     * Get the master scheduled thread pool executor maintained by the
     * ThreadPool provider.  This can be used by other modules as a centralized
     * way to schedule tasks.
     * @return
     */
    public ScheduledExecutorService
getScheduledExecutor();
}

public interface IFloodlightModule
{
     
      /**
      * Return the list of interfaces that this module implements.
      * All interfaces must inherit IFloodlightService
      * @return
      */
     
      public Collection<Class<? extends IFloodlightService>>
getModuleServices();
     
      /**
      * Instantiate (as needed) and return objects that implement each
      * of the services exported by this module.  The map returned maps
      * the implemented service to the object.  The object could be the
      * same object or different objects for different exported services.
      * @return The
map from service interface class to service implementation
      */
      public Map<Class<? extends IFloodlightService>,
                IFloodlightService> getServiceImpls();
     
      /**
      * Get a list of Modules that this module depends on.  The module system
      * will ensure that each these dependencies is resolved before the
      * subsequent calls to init().
      * @return The
Collection of IFloodlightServices that this module depends
      *         on.
      */
     
      public Collection<Class<? extends IFloodlightService>>
getModuleDependencies();
     
      /**
      * This is a hook for each module to do its <em> internal</em> initialization,
      * e.g., call setService(context.getService("Service"))
      *
      * All module dependencies are resolved when this is called, but not every module
      * is initialized.
      *
      * @param context
      * @throws FloodlightModuleException
      */
     
      void init(FloodlightModuleContext
context) throws FloodlightModuleException;
     
      /**
      * This is a hook for each module to do its <em> external</em> initializations,
      * e.g., register for callbacks or
query for state in other modules
      *
      * It is expected that this function will not block and that modules that want
      * non - event
driven CPU will spawn their own threads.
      *
      * @param context
      */
     
      void startUp(FloodlightModuleContext
context);
}

public class ThreadPool implements IThreadPoolService,
IFloodlightModule {
      protected ScheduledExecutorService executor = null ;

      // IThreadPoolService
      @Override
      public ScheduledExecutorService
getScheduledExecutor() {
           return executor ;
     }

      // IFloodlightModule
      @Override
      public Collection<Class<? extends IFloodlightService>>
getModuleServices() {
          Collection<Class<? extends IFloodlightService>>
l = new ArrayList<Class<?

extends IFloodlightService>>();

          l.add(IThreadPoolService. class );
           return l;
     }

      @Override
      public Map<Class<?

extends IFloodlightService>,
IFloodlightService> getServiceImpls() {

          Map<Class<? extends IFloodlightService>,
IFloodlightService> m = new HashMap<Class<?

extends IFloodlightService>,
IFloodlightService>();

          m.put(IThreadPoolService. class , this );
           // We are the class that implements the
service
           return m;
     }

      @Override
      public Collection<Class<? extends IFloodlightService>>
getModuleDependencies() {
           // No dependencies
           return null ;
     }

      @Override
      public void init(FloodlightModuleContext
context)
               throws FloodlightModuleException
{
           executor =
Executors. newScheduledThreadPool(15);
           // parameter - the number of threads to
keep in the pool, even if they are idle.
     }

      @Override
      public void startUp(FloodlightModuleContext
context) {
           // no-op
     }
}




版权声明:本文博客原创文章,博客,未经同意,不得转载。

上一篇:Hibernate的四种查询方式(主键查询,HQL查询,Criteria查询,本地sql查询)和修改和添加


下一篇:《DSP using MATLAB》Problem 7.10