Package generic.concurrent

Class GThreadPool

java.lang.Object
generic.concurrent.GThreadPool
public class GThreadPool extends Object
Class for managing and sharing thread pools. The GThreadPool is simplified version of the ThreadPoolExecutor, which can be confusing to use with its many configuration parameters. The GThreadPool has a simple behavior that is controlled by only two configuration parameters - the minimum number of threads and the maximum number of threads.

The simple behavior for when new tasks are submitted:
1) If there any idle threads, use that thread.
2) If all existing threads are busy and the number of threads is less than max threads, add a new thread and use it.
3) if all threads are busy and there are max number of threads, queue the item until a thread becomes free.

The simple behavior for when tasks are completed by a thread:
1) If there are tasks in the queue, start processing a new item in the newly freed thread.
2) if there are more threads that min threads, allow this thread to die if no new jobs arrive before the "KEEP ALIVE" time expires which is currently 15 seconds.
3) if there are min threads or less, allow this thread to wait forever for a new job to arrive.

  • Method Details

    • getPrivateThreadPool

      public static GThreadPool getPrivateThreadPool(String name)
      Creates a new, private thread pool with the given name.
      Parameters:
      name - the name of the thread pool
      Returns:
      a private GThreadPool with the given name.

    • getSharedThreadPool

      public static GThreadPool getSharedThreadPool(String name)
      Returns a shared GThreadPool. If a shared GThreadPool already exists with the given name, it is returned. Otherwise, a new shared GThreadPool is created and returned.
      Parameters:
      name - the name of the GThreadPool.
      Returns:
      a shared GThreadPool with the given name.

    • runAsync

      public static CompletableFuture<Void> runAsync(String poolName, Runnable r)
      Runs the given runnable in a background thread using a shared thread pool of the given name.
      Parameters:
      poolName - the thread pool name
      r - the runnable
      Returns:
      the future

    • setMaxThreadCount

      public void setMaxThreadCount(int maxThreadCount)
      Sets the max number of threads to use in this thread pool. The default is the number of processors + 1.
      Parameters:
      maxThreadCount - the maximum number of threads to use in this thread pool.

    • getMinThreadCount

      public int getMinThreadCount()
      Returns the minimum number of threads to keep alive in this thread pool.
      Returns:
      the minimum number of threads to keep alive in this thread pool.

    • setMinThreadCount

      public void setMinThreadCount(int minThreadCount)
      Sets the minimum number of threads to keep alive in this thread pool.
      Parameters:
      minThreadCount - the minimum number of threads to keep alive in this thread pool.

    • getMaxThreadCount

      public int getMaxThreadCount()
      Returns the maximum number of threads to use in this thread pool.
      Returns:
      the maximum number of threads to use in this thread pool.

    • submit

      public void submit(FutureTask<?> futureTask)
      Submits a FutreTask to be executed by a thread in this thread pool.
      Parameters:
      futureTask - the future task to be executed.

    • submit

      public Future<?> submit(Runnable task)
      Submits a runnable to be executed by this thread pool.
      Parameters:
      task - the runnable to be executed.
      Returns:
      a Future for that runnable.

    • submit

      public <T> Future<T> submit(Runnable task, T result)
      Submits a runnable to be executed by this thread pool.
      Parameters:
      task - the runnable to be executed.
      result - the result to be returned after the runnable has executed.
      Returns:
      a Future for that runnable.

    • submit

      public <T> Future<T> submit(Callable<T> task)
      Submits a callable to be executed by this thread pool.
      Parameters:
      task - the callable to be executed.
      Returns:
      a Future for that callable.

    • shutdownNow

      public void shutdownNow()

    • isPrivate

      public boolean isPrivate()
      Returns true if this is not a shared thread pool.
      Returns:
      true if this is not a shared thread pool.

    • getExecutor

      public Executor getExecutor()
      Returns the Executor used by this thread pool.

      Note: normal usage of this thread pool contraindicates accessing the executor of this pool. For managing your own jobs, you should use the method on this class directly. The intent of this method is to provide access to the executor so that it may be passed to other asynchronous APIs, such as the CompletableFuture.

      Returns:
      the executor