Class ThreadPoolExecutor

  • All Implemented Interfaces:
    ExecutorService, java.util.concurrent.Executor, java.util.concurrent.ExecutorService
    Direct Known Subclasses:
    TimeScheduledThreadPoolExecutor

    public class ThreadPoolExecutor
    extends java.util.concurrent.ThreadPoolExecutor
    implements ExecutorService
    An ExecutorService that executes each submitted task using one of possibly several pooled threads, normally configured using Executors factory methods.
    • Nested Class Summary

      • Nested classes/interfaces inherited from class java.util.concurrent.ThreadPoolExecutor

        java.util.concurrent.ThreadPoolExecutor.AbortPolicy, java.util.concurrent.ThreadPoolExecutor.CallerRunsPolicy, java.util.concurrent.ThreadPoolExecutor.DiscardOldestPolicy, java.util.concurrent.ThreadPoolExecutor.DiscardPolicy
    • Constructor Summary

      Constructors 
      Constructor Description
      ThreadPoolExecutor​(int corePoolSize, int maximumPoolSize, long keepAliveTime, java.util.concurrent.TimeUnit unit, java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue)
      Creates a new ThreadPoolExecutor with the given initial parameters and default thread factory and rejected execution handler.
      ThreadPoolExecutor​(int corePoolSize, int maximumPoolSize, long keepAliveTime, java.util.concurrent.TimeUnit unit, java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue, java.util.concurrent.RejectedExecutionHandler handler)
      Creates a new ThreadPoolExecutor with the given initial parameters and default thread factory.
      ThreadPoolExecutor​(int corePoolSize, int maximumPoolSize, long keepAliveTime, java.util.concurrent.TimeUnit unit, java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue, java.util.concurrent.ThreadFactory threadFactory)
      Creates a new ThreadPoolExecutor with the given initial parameters and default rejected execution handler.
      ThreadPoolExecutor​(int corePoolSize, int maximumPoolSize, long keepAliveTime, java.util.concurrent.TimeUnit unit, java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue, java.util.concurrent.ThreadFactory threadFactory, java.util.concurrent.RejectedExecutionHandler handler)
      Creates a new ThreadPoolExecutor with the given initial parameters.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected <T> java.util.concurrent.RunnableFuture<T> newTaskFor​(java.lang.Runnable runnable, T value)
      Returns a RunnableFuture for the given runnable and default value.
      protected <T> java.util.concurrent.RunnableFuture<T> newTaskFor​(java.util.concurrent.Callable<T> callable)
      Returns a RunnableFuture for the given callable task.
      AsyncFuture<?> submit​(java.lang.Runnable task)
      Submits a Runnable task for execution and returns a Future representing that task.
      <T> AsyncFuture<T> submit​(java.lang.Runnable task, T result)
      Submits a Runnable task for execution and returns a Future representing that task.
      <T> AsyncFuture<T> submit​(java.util.concurrent.Callable<T> task)
      Submits a value-returning task for execution and returns a Future representing the pending results of the task.
      • Methods inherited from class java.util.concurrent.ThreadPoolExecutor

        afterExecute, allowCoreThreadTimeOut, allowsCoreThreadTimeOut, awaitTermination, beforeExecute, execute, finalize, getActiveCount, getCompletedTaskCount, getCorePoolSize, getKeepAliveTime, getLargestPoolSize, getMaximumPoolSize, getPoolSize, getQueue, getRejectedExecutionHandler, getTaskCount, getThreadFactory, isShutdown, isTerminated, isTerminating, prestartAllCoreThreads, prestartCoreThread, purge, remove, setCorePoolSize, setKeepAliveTime, setMaximumPoolSize, setRejectedExecutionHandler, setThreadFactory, shutdown, shutdownNow, terminated, toString
      • Methods inherited from class java.util.concurrent.AbstractExecutorService

        invokeAll, invokeAll, invokeAny, invokeAny
      • Methods inherited from class java.lang.Object

        clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
      • Methods inherited from interface java.util.concurrent.Executor

        execute
      • Methods inherited from interface java.util.concurrent.ExecutorService

        awaitTermination, invokeAll, invokeAll, invokeAny, invokeAny, isShutdown, isTerminated, shutdown, shutdownNow
    • Constructor Detail

      • ThreadPoolExecutor

        public ThreadPoolExecutor​(int corePoolSize,
                                  int maximumPoolSize,
                                  long keepAliveTime,
                                  java.util.concurrent.TimeUnit unit,
                                  java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue)
        Creates a new ThreadPoolExecutor with the given initial parameters and default thread factory and rejected execution handler. It may be more convenient to use one of the Executors factory methods instead of this general purpose constructor.
        Parameters:
        corePoolSize - the number of threads to keep in the pool, even if they are idle, unless allowCoreThreadTimeOut is set
        maximumPoolSize - the maximum number of threads to allow in the pool
        keepAliveTime - when the number of threads is greater than the core, this is the maximum time that excess idle threads will wait for new tasks before terminating.
        unit - the time unit for the keepAliveTime argument
        workQueue - the queue to use for holding tasks before they are executed. This queue will hold only the Runnable tasks submitted by the execute method.
        Throws:
        java.lang.IllegalArgumentException - if one of the following holds:
        corePoolSize < 0
        keepAliveTime < 0
        maximumPoolSize <= 0
        maximumPoolSize < corePoolSize
        java.lang.NullPointerException - if workQueue is null
      • ThreadPoolExecutor

        public ThreadPoolExecutor​(int corePoolSize,
                                  int maximumPoolSize,
                                  long keepAliveTime,
                                  java.util.concurrent.TimeUnit unit,
                                  java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue,
                                  java.util.concurrent.ThreadFactory threadFactory)
        Creates a new ThreadPoolExecutor with the given initial parameters and default rejected execution handler.
        Parameters:
        corePoolSize - the number of threads to keep in the pool, even if they are idle, unless allowCoreThreadTimeOut is set
        maximumPoolSize - the maximum number of threads to allow in the pool
        keepAliveTime - when the number of threads is greater than the core, this is the maximum time that excess idle threads will wait for new tasks before terminating.
        unit - the time unit for the keepAliveTime argument
        workQueue - the queue to use for holding tasks before they are executed. This queue will hold only the Runnable tasks submitted by the execute method.
        threadFactory - the factory to use when the executor creates a new thread
        Throws:
        java.lang.IllegalArgumentException - if one of the following holds:
        corePoolSize < 0
        keepAliveTime < 0
        maximumPoolSize <= 0
        maximumPoolSize < corePoolSize
        java.lang.NullPointerException - if workQueue or threadFactory is null
      • ThreadPoolExecutor

        public ThreadPoolExecutor​(int corePoolSize,
                                  int maximumPoolSize,
                                  long keepAliveTime,
                                  java.util.concurrent.TimeUnit unit,
                                  java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue,
                                  java.util.concurrent.RejectedExecutionHandler handler)
        Creates a new ThreadPoolExecutor with the given initial parameters and default thread factory.
        Parameters:
        corePoolSize - the number of threads to keep in the pool, even if they are idle, unless allowCoreThreadTimeOut is set
        maximumPoolSize - the maximum number of threads to allow in the pool
        keepAliveTime - when the number of threads is greater than the core, this is the maximum time that excess idle threads will wait for new tasks before terminating.
        unit - the time unit for the keepAliveTime argument
        workQueue - the queue to use for holding tasks before they are executed. This queue will hold only the Runnable tasks submitted by the execute method.
        handler - the handler to use when execution is blocked because the thread bounds and queue capacities are reached
        Throws:
        java.lang.IllegalArgumentException - if one of the following holds:
        corePoolSize < 0
        keepAliveTime < 0
        maximumPoolSize <= 0
        maximumPoolSize < corePoolSize
        java.lang.NullPointerException - if workQueue or handler is null
      • ThreadPoolExecutor

        public ThreadPoolExecutor​(int corePoolSize,
                                  int maximumPoolSize,
                                  long keepAliveTime,
                                  java.util.concurrent.TimeUnit unit,
                                  java.util.concurrent.BlockingQueue<java.lang.Runnable> workQueue,
                                  java.util.concurrent.ThreadFactory threadFactory,
                                  java.util.concurrent.RejectedExecutionHandler handler)
        Creates a new ThreadPoolExecutor with the given initial parameters.
        Parameters:
        corePoolSize - the number of threads to keep in the pool, even if they are idle, unless allowCoreThreadTimeOut is set
        maximumPoolSize - the maximum number of threads to allow in the pool
        keepAliveTime - when the number of threads is greater than the core, this is the maximum time that excess idle threads will wait for new tasks before terminating.
        unit - the time unit for the keepAliveTime argument
        workQueue - the queue to use for holding tasks before they are executed. This queue will hold only the Runnable tasks submitted by the execute method.
        threadFactory - the factory to use when the executor creates a new thread
        handler - the handler to use when execution is blocked because the thread bounds and queue capacities are reached
        Throws:
        java.lang.IllegalArgumentException - if one of the following holds:
        corePoolSize < 0
        keepAliveTime < 0
        maximumPoolSize <= 0
        maximumPoolSize < corePoolSize
        java.lang.NullPointerException - if workQueue or threadFactory or handler is null
    • Method Detail

      • newTaskFor

        protected <T> java.util.concurrent.RunnableFuture<T> newTaskFor​(java.lang.Runnable runnable,
                                                                        T value)
        Returns a RunnableFuture for the given runnable and default value.
        Overrides:
        newTaskFor in class java.util.concurrent.AbstractExecutorService
        Parameters:
        runnable - the runnable task being wrapped
        value - the default value for the returned future
        Returns:
        a RunnableFuture which, when run, will run the underlying runnable and which, as a Future, will yield the given value as its result and provide for cancellation of the underlying task
        Since:
        1.6
      • newTaskFor

        protected <T> java.util.concurrent.RunnableFuture<T> newTaskFor​(java.util.concurrent.Callable<T> callable)
        Returns a RunnableFuture for the given callable task.
        Overrides:
        newTaskFor in class java.util.concurrent.AbstractExecutorService
        Parameters:
        callable - the callable task being wrapped
        Returns:
        a RunnableFuture which, when run, will call the underlying callable and which, as a Future, will yield the callable's result as its result and provide for cancellation of the underlying task
        Since:
        1.6
      • submit

        @Nonnull
        public AsyncFuture<?> submit​(@Nonnull
                                     java.lang.Runnable task)
        Description copied from interface: ExecutorService
        Submits a Runnable task for execution and returns a Future representing that task. The Future's get method will return null upon successful completion.
        Specified by:
        submit in interface ExecutorService
        Specified by:
        submit in interface java.util.concurrent.ExecutorService
        Overrides:
        submit in class java.util.concurrent.AbstractExecutorService
        Parameters:
        task - the task to submit
        Returns:
        a Future representing pending completion of the task
        Throws:
        java.util.concurrent.RejectedExecutionException
        java.lang.NullPointerException - if the task is null
      • submit

        @Nonnull
        public <T> AsyncFuture<T> submit​(@Nonnull
                                         java.lang.Runnable task,
                                         T result)
        Description copied from interface: ExecutorService
        Submits a Runnable task for execution and returns a Future representing that task. The Future's get method will return the given result upon successful completion.
        Specified by:
        submit in interface ExecutorService
        Specified by:
        submit in interface java.util.concurrent.ExecutorService
        Overrides:
        submit in class java.util.concurrent.AbstractExecutorService
        Type Parameters:
        T - the type of the result
        Parameters:
        task - the task to submit
        result - the result to return
        Returns:
        a Future representing pending completion of the task
        Throws:
        java.util.concurrent.RejectedExecutionException
        java.lang.NullPointerException - if the task is null
      • submit

        @Nonnull
        public <T> AsyncFuture<T> submit​(@Nonnull
                                         java.util.concurrent.Callable<T> task)
        Description copied from interface: ExecutorService
        Submits a value-returning task for execution and returns a Future representing the pending results of the task. The Future's get method will return the task's result upon successful completion.

        If you would like to immediately block waiting for a task, you can use constructions of the form result = exec.submit(aCallable).get();

        Note: The Executors class includes a set of methods that can convert some other common closure-like objects, for example, PrivilegedAction to Callable form so they can be submitted.

        Specified by:
        submit in interface ExecutorService
        Specified by:
        submit in interface java.util.concurrent.ExecutorService
        Overrides:
        submit in class java.util.concurrent.AbstractExecutorService
        Type Parameters:
        T - the type of the task's result
        Parameters:
        task - the task to submit
        Returns:
        a Future representing pending completion of the task
        Throws:
        java.util.concurrent.RejectedExecutionException
        java.lang.NullPointerException - if the task is null