Package net.sourceforge.jtds.util

Class TimerThread

  • All Implemented Interfaces:
    java.lang.Runnable
    public class TimerThread
extends java.lang.Thread
    Simple timer class used to implement login and query timeouts.

    This thread runs as a Daemon thread to ensure that the java VM will exit correctly when normal execution is complete.

    It provides both a singleton implementation and a default constructor for the case when more than one timer thread is desired.

    Version:
    $Id: TimerThread.java,v 1.5.2.3 2010-05-17 09:16:06 ickzon Exp $
    Author:
    Alin Sinpalean, Mike Hutchinson

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static interface  TimerThread.TimerListener
      Interface to be implemented by classes that request timer services.
      private static class  TimerThread.TimerRequest
      Internal class associating a login or query timeout value with a target TimerListener.

      • Nested classes/interfaces inherited from class java.lang.Thread

        java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static TimerThread instance
      Singleton instance.
      private long nextTimeout
      Time when the first request time out should occur.
      private java.util.LinkedList timerList
      List of TimerRequests to execute, ordered by time.

      • Fields inherited from class java.lang.Thread

        MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

    • Constructor Summary

      Constructors 
      Constructor Description
      TimerThread()
      Construct a new TimerThread instance.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean cancelTimer​(java.lang.Object handle)
      Remove a redundant timer before it expires.
      static TimerThread getInstance()
      Singleton getter.
      boolean hasExpired​(java.lang.Object handle)
      Check whether a timer has expired.
      void run()
      Execute the TimerThread main loop.
      java.lang.Object setTimer​(int timeout, TimerThread.TimerListener l)
      Add a timer request to the queue.
      static void stopTimer()
      Completely stops the timer and its underlying Java thread, discarding all pending timeouts.
      private void updateNextTimeout()
      Internal method that updates the value of nextTimeout.

      • Methods inherited from class java.lang.Thread

        activeCount, checkAccess, clone, countStackFrames, currentThread, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, onSpinWait, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, suspend, toString, yield

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • instance

        private static TimerThread instance
        Singleton instance.

      • timerList

        private final java.util.LinkedList timerList
        List of TimerRequests to execute, ordered by time.

      • nextTimeout

        private long nextTimeout
        Time when the first request time out should occur.

    • Constructor Detail

      • TimerThread

        public TimerThread()
        Construct a new TimerThread instance.

    • Method Detail

      • getInstance

        public static TimerThread getInstance()
        Singleton getter.

      • run

        public void run()
        Execute the TimerThread main loop.
        Specified by:
        run in interface java.lang.Runnable
        Overrides:
        run in class java.lang.Thread

      • setTimer

        public java.lang.Object setTimer​(int timeout,
                                 TimerThread.TimerListener l)
        Add a timer request to the queue.

        The queue is ordered by time so that the head of the list is always the first timer to expire.

        Parameters:
        timeout - the interval in milliseconds after which the timer will expire
        l - TimerListener to be notified on timeout
        Returns:
        a handle to the timer request, that can later be used with cancelTimer

      • cancelTimer

        public boolean cancelTimer​(java.lang.Object handle)
        Remove a redundant timer before it expires.
        Parameters:
        handle - handle to the request to be removed from the queue (a TimerRequest instance)
        Returns:
        true if timer had not expired

      • stopTimer

        public static void stopTimer()
        Completely stops the timer and its underlying Java thread, discarding all pending timeouts. Any subsequent invocation of getInstance() will restart the timer.

      • hasExpired

        public boolean hasExpired​(java.lang.Object handle)
        Check whether a timer has expired.
        Parameters:
        handle - handle to the request to be checked for expiry (a TimerRequest instance)
        Returns:
        true if timer has expired

      • updateNextTimeout

        private void updateNextTimeout()
        Internal method that updates the value of nextTimeout.