Algorithm implementation of efficient triggering of a large number of timeout tasks in ring queue

The time-out triggering algorithm based on the ring queue only needs a timer to trigger the batch timeout task, which is low CPU consumption and high efficiency. The following is a simple implementation of this algorithm.

1,taskholder.java

package com.zws.timer;/** *  *  @author  wensh.zhu *  @date   2018-04-22 */public class taskholder {/**  the number of laps to wait for a task, that is, the task needs to walk a few laps **/private int  Cycles;private int delays;private runnable task;public taskholder ()  {}public  taskholder (Int cycles, int delays, runnable task)  {this.cycles =  cycles;this.delays = delays;this.task = task;} Public boolean istimeout ()  {return cycles <= 0;} Public void cutdown ()  {cycles --;} Public int getcycles ()  {return cycles;} Public void setcycles (Int cycles)  {this.cycles = cycles;} Public int getdelays ()  {return delays;} Public void setdelays (Int delays)  {this.delays = delays;} Public runnable gettask ()  {return task;} Public void&nBsp;settask (Runnable task)  {this.task = task;} @Overridepublic  string tostring ()  {return  "taskholder[cycles="  + cycles +   ",  delays="  + delays +  "]";}}

2,timercontext.java

package com.zws.timer;import java.util.map;import java.util.queue;import  java.util.concurrent.concurrenthashmap;import java.util.concurrent.concurrentlinkedqueue;/** *   *  @author  wensh.zhu *  @date  2018-04-22 */public class  Timercontext {public static final int default_ticks = 60;public static  final int DEFAULT_TICK_DURATION = 1;private Map<Integer, Queue< taskholder>> taskholders;private volatile int currenttick = 0;/**  Tick lap length  **/private int ticks = DEFAULT_TICKS;/**  time interval per tick, unit: Seconds **/private  int tickduration = default_tick_duration;public timercontext ()  {init ();} Public timercontext (int ticks, int tickduration)  {if  (ticks <= 0) Throw new illegalargumentexception ("ticks  must be greater than 0 ");if  (tickduration <= 0) throw new  IllegalArgumentException ("tickduration must be greater than 0"); this.ticks =  ticks;this.tickduration = tickduration;init ();} Private void init ()  {taskholders = new concurrenthashmap<integer, queue <TaskHolder>> (;for ) (int i = 0; i < ticks; i ++) Taskholders.put (i, new concurrentlinkedqueue<taskholder> ());} /** *  Add a timed task and calculate the number of laps to walk and index *  @param  task *  @param  delays */ Public void addtask (runnable task, int delays)  {if  (task == null)  throw new nullpointerexception ("Task must not be null");if  (delays  <=0)  throw new illegalargumentexception ("delays must be greater  than 0 ");int allseconds = ticks * tickduration;int cycles =  delays / allseconds;int index =  (delays % allseconds)  /  Tickduration)  + currentTick; Taskholder metadata = new taskholder (Cycles, delays, task); TaskHolders.get (index ). Add (MetaData);} Public int tick ()  {currentTick =  (currenttick + 1)  % ticks;return  currenttick;} Public queue<taskholder> getcurrenttasks ()  {return taskholders.get (CurrentTick);} Public int getcurrenttick ()  {return currenttick;} Public int getticks ()  {return ticks;} Public int gettickduration ()  {return tickduration;} @Overridepublic  string tostring ()  {return  "timercontext [timers="  +  taskholders +  ",  ticks="  + ticks +  ",  tickduration=" + tickDuration+ ",  currenttick= " + currentTick + "] ";}} 

3,timerscheduler.java

package com.zws.timer;import java.io.ioexception;import java.util.iterator;import  java.util.queue;import java.util.timer;import java.util.timertask;/** *  is used to determine if the timer is up, perform a task, Maintain timer status.  *  @author  wensh.zhu *  @date  2018-04-22 */public class  timerscheduler extends timertask {private timercontext timercontext;public  Timerscheduler ()  {}public timerscheduler (Timercontext timercontext)  {this.timerContext  = timercontext;} /** *  timing Detection, if the timer trigger time to delete from the collection and perform the task, otherwise the number of laps minus one.  */@Overridepublic  void run ()  {if  (timercontext == null)  return; Queue<taskholder> timers = timercontext.getcurrenttasks ();Iterator<TaskHolder>  itor = timers.iterator ();while  (Itor.hasnext ())  {TaskHolder timer =  Itor.next ();if  (Timer.istimeout ())  {itor.remove (); New threAD (Timer.gettask ()). Start ();}  else {timer.cutdown ();}} Timercontext.tick ();} Public void addtask (runnable task, int delays)  {timercontext.addtask (task,  delays);} Public timercontext gettimercontext ()  {return timercontext;} Public void settimercontext (Timercontext timercontext)  {this.timerContext =  Timercontext;} Public static void main (String[] args)  throws ioexception {timercontext  context = new timercontext (60, 1); Timerscheduler sheduler = new timerscheduler (context); Sheduler.addtask (New Runnable ()  {public void run ()  {system.out.println (Dateutils.now ());}}, 60); System.out.println (Dateutils.now ()); Timer timer = new timer (); Timer.scheduleatfixedrate (sheduler, 0,  Context.gettickduration ()  * 1000l); System.in.read ();}}

4,dateutils.java

Package Com.zws.timer;import java.time.localdatetime;import java.time.format.datetimeformatter;/** * * @author Wensh.zhu * @date 2018-04-22 */public class Dateutils {public static final String Default_pattern = "Yyyy-mm-dd HH:mm:ss"; public static String Now () {LocalDateTime time = Localdatetime.now (); return Time.format (Datetimeformatter.ofpattern ( Default_pattern));} public static String plusseconds (int seconds) {LocalDateTime time = Localdatetime.now (); time.plusseconds (seconds); Return Time.format (Datetimeformatter.ofpattern (Default_pattern));}}

Algorithm implementation of efficient triggering of a large number of timeout tasks in ring queue