Package jadex.commons.concurrent

Class Executor

  • All Implemented Interfaces:
    java.lang.Runnable
    public class Executor
extends java.lang.Object
implements java.lang.Runnable
    A helper class for running a single instance of code using the thread pool. The code to be executed has to be placed in the code() method. Once created, the execute() method may be called as often as desired. When no thread is currently executing the object, a new thread is used from the thread pool. Otherwise, the already existing thread continues execution. After shutdown() is called, the executor stops execution, even when execute() is called afterwards.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected IExecutable executable
      The executable.
      static java.lang.ThreadLocal<Executor> EXECUTOR
      The executor belonging to a thread.
      protected int exethreadcnt
      The number of current threads for this executor.
      protected java.lang.Object monitor
      The monitor to synchronize with at thread start (if any).
      protected boolean running
      Flag indicating if the thread is running.
      protected java.util.List<Future<java.lang.Void>> shutdownfutures
      The shutdown futures.
      protected java.util.List<java.lang.Object> switchtos
      The monitors of blocked threads that need to be reactivated.
      protected IThreadPool threadpool
      The thread pool.
      protected java.util.Map<java.lang.Object,​java.lang.Throwable> throwables
      The exceptions (if any) to be thrown in threads that need to be reactivated.
      protected boolean wanttorun
      Flag indicating if the thread wants to run.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void blockThread​(java.lang.Object monitor)
      Adjust to execution of current thread to be blocked.
      protected boolean code()
      The code to be run.
      boolean execute()
      Make sure a thread is executing the code.
      protected int getThreadCount()
      Get the number of threads (running blocked) for this executor.
      protected boolean isRunning()
      Check if the executor is running.
      boolean isSwitching()
      Check if the executor wants to switch threads.
      void run()
      Execute the code.
      void setExecutable​(IExecutable executable)
      Set the executable.
      IFuture<java.lang.Void> shutdown()
      Shutdown the executor.
      void switchThread​(java.lang.Object monitor, java.lang.Throwable t)
      Cease execution of the current thread and switch to another thread waiting for the given monitor.
      java.lang.String toString()
      String representation.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • EXECUTOR

        public static final java.lang.ThreadLocal<Executor> EXECUTOR
        The executor belonging to a thread.

      • running

        protected boolean running
        Flag indicating if the thread is running.

      • wanttorun

        protected boolean wanttorun
        Flag indicating if the thread wants to run.

      • threadpool

        protected IThreadPool threadpool
        The thread pool.

      • executable

        protected IExecutable executable
        The executable.

      • shutdownfutures

        protected java.util.List<Future<java.lang.Void>> shutdownfutures
        The shutdown futures.

      • monitor

        protected java.lang.Object monitor
        The monitor to synchronize with at thread start (if any).

      • exethreadcnt

        protected int exethreadcnt
        The number of current threads for this executor.

      • switchtos

        protected java.util.List<java.lang.Object> switchtos
        The monitors of blocked threads that need to be reactivated.

      • throwables

        protected java.util.Map<java.lang.Object,​java.lang.Throwable> throwables
        The exceptions (if any) to be thrown in threads that need to be reactivated.

    • Constructor Detail

      • Executor

        public Executor​(IThreadPool threadpool)
        Create an executor object. Constructor for subclasses overriding the code() method.

    • Method Detail

      • run

        public void run()
        Execute the code.
        Specified by:
        run in interface java.lang.Runnable

      • execute

        public boolean execute()
        Make sure a thread is executing the code.

      • shutdown

        public IFuture<java.lang.Void> shutdown()
        Shutdown the executor.

      • setExecutable

        public void setExecutable​(IExecutable executable)
        Set the executable.
        Parameters:
        executable - The executable.

      • code

        protected boolean code()
        The code to be run.
        Returns:
        True, when execution should continue.

      • isRunning

        protected boolean isRunning()
        Check if the executor is running. Should only be called, when access to executor is correctly synchronized, otherwise inconsistent values might be returned.

      • getThreadCount

        protected int getThreadCount()
        Get the number of threads (running blocked) for this executor.

      • switchThread

        public void switchThread​(java.lang.Object monitor,
                         java.lang.Throwable t)
        Cease execution of the current thread and switch to another thread waiting for the given monitor.
        Parameters:
        monitor - The monitor to be notified.
        t - The exception to be thrown on the unblocked thread (null for continuing normal execution).

      • blockThread

        public void blockThread​(java.lang.Object monitor)
        Adjust to execution of current thread to be blocked.

      • toString

        public java.lang.String toString()
        String representation.
        Overrides:
        toString in class java.lang.Object

      • isSwitching

        public boolean isSwitching()
        Check if the executor wants to switch threads.