Package org.quartz.simpl

Class ZeroSizeThreadPool

  • All Implemented Interfaces:
    ThreadPool
    public class ZeroSizeThreadPool
extends java.lang.Object
implements ThreadPool

    This is class is a simple implementation of a zero size thread pool, based on the ThreadPool interface.

    The pool has zero Threads and does not grow or shrink based on demand. Which means it is obviously not useful for most scenarios. When it may be useful is to prevent creating any worker threads at all - which may be desirable for the sole purpose of preserving system resources in the case where the scheduler instance only exists in order to schedule jobs, but which will never execute jobs (e.g. will never have start() called on it).

    Author:
    Wayne Fay

    • Constructor Summary

      Constructors 
      Constructor Description
      ZeroSizeThreadPool()
      Create a new ZeroSizeThreadPool.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int blockForAvailableThreads()
      Determines the number of threads that are currently available in in the pool.
      org.slf4j.Logger getLog()  
      int getPoolSize()
      Get the current number of threads in the ThreadPool.
      void initialize()
      Must be called before the ThreadPool is used, in order to give the it a chance to initialize.
      boolean runInThread​(java.lang.Runnable runnable)
      Execute the given Runnable in the next available Thread.
      void setInstanceId​(java.lang.String schedInstId)
      Inform the ThreadPool of the Scheduler instance's Id, prior to initialize being invoked.
      void setInstanceName​(java.lang.String schedName)
      Inform the ThreadPool of the Scheduler instance's name, prior to initialize being invoked.
      void shutdown()  
      void shutdown​(boolean waitForJobsToComplete)
      Called by the QuartzScheduler to inform the ThreadPool that it should free up all of it's resources because the scheduler is shutting down.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • ZeroSizeThreadPool

        public ZeroSizeThreadPool()

        Create a new ZeroSizeThreadPool.

    • Method Detail

      • getLog

        public org.slf4j.Logger getLog()

      • getPoolSize

        public int getPoolSize()
        Description copied from interface: ThreadPool

        Get the current number of threads in the ThreadPool.

        Specified by:
        getPoolSize in interface ThreadPool

      • shutdown

        public void shutdown()

      • shutdown

        public void shutdown​(boolean waitForJobsToComplete)
        Description copied from interface: ThreadPool

        Called by the QuartzScheduler to inform the ThreadPool that it should free up all of it's resources because the scheduler is shutting down.

        Specified by:
        shutdown in interface ThreadPool

      • runInThread

        public boolean runInThread​(java.lang.Runnable runnable)
        Description copied from interface: ThreadPool

        Execute the given Runnable in the next available Thread.

        The implementation of this interface should not throw exceptions unless there is a serious problem (i.e. a serious misconfiguration). If there are no immediately available threads false should be returned.

        Specified by:
        runInThread in interface ThreadPool
        Returns:
        true, if the runnable was assigned to run on a Thread.

      • blockForAvailableThreads

        public int blockForAvailableThreads()
        Description copied from interface: ThreadPool

        Determines the number of threads that are currently available in in the pool. Useful for determining the number of times runInThread(Runnable) can be called before returning false.

        The implementation of this method should block until there is at least one available thread.

        Specified by:
        blockForAvailableThreads in interface ThreadPool
        Returns:
        the number of currently available threads

      • setInstanceId

        public void setInstanceId​(java.lang.String schedInstId)
        Description copied from interface: ThreadPool

        Inform the ThreadPool of the Scheduler instance's Id, prior to initialize being invoked.

        Specified by:
        setInstanceId in interface ThreadPool

      • setInstanceName

        public void setInstanceName​(java.lang.String schedName)
        Description copied from interface: ThreadPool

        Inform the ThreadPool of the Scheduler instance's name, prior to initialize being invoked.

        Specified by:
        setInstanceName in interface ThreadPool