Package com.vividsolutions.jump.workbench.ui.renderer

Class ThreadQueue

  • public class ThreadQueue
extends Object
    This thread queue executes at maximum N Runnables in parallel were N is a given number of worker threads that should be used. If N threads are running and busy each further incoming Runnable is queued until one of the threads has finished its current job. If a worker thread becomes idle (no more job in the queue) it is hold alive for 5 seconds. If during this period of time no new Runnable is enqueued the worker thread dies.
    Author:
    Sascha L. Teichmann (sascha.teichmann@intevation.de)

    • Field Detail

      • WORKER_STAY_ALIVE_TIME

        public static final long WORKER_STAY_ALIVE_TIME
        The time a worker thread stays alive if idle
        See Also:
        Constant Field Values

      • runningThreads

        protected int[] runningThreads
        Number of running threads

      • maxRunningThreads

        protected int maxRunningThreads
        max. Number of threads running parallel

      • waitingThreads

        protected int waitingThreads
        Number of threads that are currently idle

      • queuedRunnables

        protected final LinkedList queuedRunnables
        The queue of Runnables jobs waiting to be run

      • disposed

        protected boolean disposed
        Singals that the ThreadQueue is going to quit

      • listeners

        protected ArrayList listeners
        List of Listeners

    • Constructor Detail

      • ThreadQueue

        public ThreadQueue()
        Creates a ThreadQueue with one worker thread.

      • ThreadQueue

        public ThreadQueue​(int maxRunningThreads)
        Creates a ThreadQueue with a given number of worker threads.
        Parameters:
        maxRunningThreads - the max. number of threads to be run parallel.

    • Method Detail

      • add

        public void add​(ThreadQueue.Listener listener)
        Adds a Listener to this ThreadQueue.
        Parameters:
        listener - the listener to add.

      • remove

        public void remove​(ThreadQueue.Listener listener)
        Removes a Listener from this ThreadQueue.
        Parameters:
        listener - the listener to be removed.

      • fireAllRunningThreadsFinished

        protected void fireAllRunningThreadsFinished()
        Informs Listeners of the fact that the number of running threads went to zero.

      • runningThreads

        public int runningThreads()
        The number of currently running worker threads.
        Returns:
        number of currently running worker threads.

      • getRunningThreads

        public int getRunningThreads()
        The number of currently running worker threads. Alias for runningThreads()
        Returns:
        number of currently running worker threads.

      • waitingRunnables

        public int waitingRunnables()
        The number of currently waiting Runnables.
        Returns:
        number of currently waiting Runnables.

      • waitingThreads

        public int waitingThreads()
        The number of currently idle worker threads.
        Returns:
        number of currently idle worker threads.

      • add

        public void add​(Runnable runnable)
        Adds a Runnables to the queue. It will be run in one of the worker threads.
        Parameters:
        runnable - The Runnables to add

      • clear

        public void clear()
        Empties the queue of waiting Runnables.

      • dispose

        public void dispose()
        Shuts down the ThreadQueue.