Package org.jgroups.util

Class HashedTimingWheel

java.lang.Object
org.jgroups.util.HashedTimingWheel
All Implemented Interfaces:
Runnable, ThreadManager, TimeScheduler
public class HashedTimingWheel extends Object implements TimeScheduler, Runnable
Implementation of TimeScheduler. Uses a hashed timing wheel [1]. [1] http://www.cse.wustl.edu/~cdgill/courses/cs6874/TimingWheels.ppt
Author:
Bela Ban

  • Field Details

    • running

      protected volatile boolean running

    • log

      protected static final Log log

    • threadDecorator

      protected ThreadDecorator threadDecorator

    • timer_thread_factory

      protected ThreadFactory timer_thread_factory

    • wheel_size

      protected int wheel_size

    • tick_time

      protected long tick_time

    • ROTATION_TIME

      protected final long ROTATION_TIME

    • wheel

      protected final List<HashedTimingWheel.MyTask>[] wheel

    • wheel_position

      protected int wheel_position

  • Constructor Details

    • HashedTimingWheel

      public HashedTimingWheel()
      Create a scheduler that executes tasks in dynamically adjustable intervals

    • HashedTimingWheel

      public HashedTimingWheel(ThreadFactory factory, int min_threads, int max_threads, long keep_alive_time, int max_queue_size, int wheel_size, long tick_time)

    • HashedTimingWheel

      public HashedTimingWheel(int corePoolSize)

  • Method Details

    • getThreadDecorator

      public ThreadDecorator getThreadDecorator()
      Description copied from interface: ThreadManager
      Gets the ThreadDecorator associated with this manager.
      Specified by:
      getThreadDecorator in interface ThreadManager
      Returns:
      the ThreadDecorator, or null if there is none.

    • setThreadDecorator

      public void setThreadDecorator(ThreadDecorator threadDecorator)
      Description copied from interface: ThreadManager
      Sets the ThreadDecorator associated this manager should use.
      Specified by:
      setThreadDecorator in interface ThreadManager
      Parameters:
      threadDecorator - the ThreadDecorator, or null.

    • setThreadFactory

      public void setThreadFactory(ThreadFactory factory)
      Specified by:
      setThreadFactory in interface TimeScheduler

    • getMinThreads

      public int getMinThreads()
      Description copied from interface: TimeScheduler
      Returns the configured core threads, or -1 if not applicable
      Specified by:
      getMinThreads in interface TimeScheduler
      Returns:

    • setMinThreads

      public void setMinThreads(int size)
      Description copied from interface: TimeScheduler
      Sets the core pool size. Can be ignored if not applicable
      Specified by:
      setMinThreads in interface TimeScheduler

    • getMaxThreads

      public int getMaxThreads()
      Description copied from interface: TimeScheduler
      Returns the configured max threads, or -1 if not applicable
      Specified by:
      getMaxThreads in interface TimeScheduler
      Returns:

    • setMaxThreads

      public void setMaxThreads(int size)
      Description copied from interface: TimeScheduler
      Sets the max pool size. Can be ignored if not applicable
      Specified by:
      setMaxThreads in interface TimeScheduler

    • getKeepAliveTime

      public long getKeepAliveTime()
      Description copied from interface: TimeScheduler
      Returns the keep alive time (in ms) of the thread pool, or -1 if not applicable
      Specified by:
      getKeepAliveTime in interface TimeScheduler

    • setKeepAliveTime

      public void setKeepAliveTime(long time)
      Description copied from interface: TimeScheduler
      Sets the keep alive time (in ms) of the thread pool. Can be ignored if not applicable
      Specified by:
      setKeepAliveTime in interface TimeScheduler

    • getCurrentThreads

      public int getCurrentThreads()
      Description copied from interface: TimeScheduler
      Returns the current threads in the pool, or -1 if not applicable
      Specified by:
      getCurrentThreads in interface TimeScheduler
      Returns:

    • getQueueSize

      public int getQueueSize()

    • dumpTimerTasks

      public String dumpTimerTasks()
      Description copied from interface: TimeScheduler
      Returns a list of tasks currently waiting for execution. If there are a lot of tasks, the returned string should probably only return the number of tasks rather than a full dump.
      Specified by:
      dumpTimerTasks in interface TimeScheduler
      Returns:

    • execute

      public void execute(Runnable task)
      Description copied from interface: TimeScheduler
      Executes command with zero required delay. This has effect equivalent to schedule(command, 0, anyUnit).
      Specified by:
      execute in interface TimeScheduler
      Parameters:
      task - the task to execute

    • schedule

      public Future<?> schedule(Runnable work, long delay, TimeUnit unit)
      Description copied from interface: TimeScheduler
      Creates and executes a one-shot action that becomes enabled after the given delay.
      Specified by:
      schedule in interface TimeScheduler
      Parameters:
      work - the task to execute
      delay - the time from now to delay execution
      unit - the time unit of the delay parameter
      Returns:
      a ScheduledFuture representing pending completion of the task and whose get() method will return null upon completion

    • scheduleWithFixedDelay

      public Future<?> scheduleWithFixedDelay(Runnable task, long initial_delay, long delay, TimeUnit unit)
      Description copied from interface: TimeScheduler
      Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given delay between the termination of one execution and the commencement of the next. If any execution of the task encounters an exception, subsequent executions are suppressed. Otherwise, the task will only terminate via cancellation or termination of the executor.
      Specified by:
      scheduleWithFixedDelay in interface TimeScheduler
      Parameters:
      task - the task to execute
      initial_delay - the time to delay first execution
      delay - the delay between the termination of one execution and the commencement of the next
      unit - the time unit of the initialDelay and delay parameters
      Returns:
      a ScheduledFuture representing pending completion of the task, and whose get() method will throw an exception upon cancellation

    • scheduleAtFixedRate

      public Future<?> scheduleAtFixedRate(Runnable task, long initial_delay, long delay, TimeUnit unit)
      Description copied from interface: TimeScheduler
      Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period; that is executions will commence after initialDelay then initialDelay+period, then initialDelay + 2 * period, and so on. If any execution of the task encounters an exception, subsequent executions are suppressed. Otherwise, the task will only terminate via cancellation or termination of the executor. If any execution of this task takes longer than its period, then subsequent executions may start late, but will not concurrently execute.
      Specified by:
      scheduleAtFixedRate in interface TimeScheduler
      Parameters:
      task - the task to execute
      initial_delay - the time to delay first execution
      delay - the period between successive executions
      unit - the time unit of the initialDelay and period parameters
      Returns:
      a ScheduledFuture representing pending completion of the task, and whose get() method will throw an exception upon cancellation

    • scheduleWithDynamicInterval

      public Future<?> scheduleWithDynamicInterval(TimeScheduler.Task task)
      Schedule a task for execution at varying intervals. After execution, the task will get rescheduled after TimeScheduler.Task.nextInterval() milliseconds. The task is neve done until nextInterval() return a value invalid input: '<'= 0 or the task is cancelled.
      Specified by:
      scheduleWithDynamicInterval in interface TimeScheduler
      Parameters:
      task - the task to execute Task is rescheduled relative to the last time it actually started execution

      false:
      Task is scheduled relative to its last execution schedule. This has the effect that the time between two consecutive executions of the task remains the same.

      Note that relative is always true; we always schedule the next execution relative to the last *actual*

    • size

      public int size()
      Returns the number of tasks currently in the timer
      Specified by:
      size in interface TimeScheduler
      Returns:
      The number of tasks currently in the timer

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • stop

      public void stop()
      Stops the timer, cancelling all tasks
      Specified by:
      stop in interface TimeScheduler
      Throws:
      InterruptedException - if interrupted while waiting for thread to return

    • isShutdown

      public boolean isShutdown()
      Description copied from interface: TimeScheduler
      Returns true if stop() has been called, false otherwise
      Specified by:
      isShutdown in interface TimeScheduler

    • run

      public void run()
      Specified by:
      run in interface Runnable

    • _run

      protected void _run()

    • init

      protected void init()

    • startRunner

      protected void startRunner()

    • stopRunner

      protected void stopRunner()