最新版本xxl-job中调度部分没有采用quartz，而是线程+timewheel
这部分代码位于xxl-job-admin项目中。基本思路是通过ConcurrentHashMap作为timewheel记录每秒处理的jobId列表。
- scheduleThread while循环从DB中轮询jobId触发时间是否到了
- 到的话立即执行
- 超过5s不执行，更新下次触发时间
- 5s以内放入timewheel中秒对应的槽位
- ringThread中while循环轮询当前秒对应槽位中jobId列表并执行
- ringThread中有些优化：比如秒对齐，向前多取一个槽位等
package com.xxl.job.admin.core.thread;
import com.xxl.job.admin.core.conf.XxlJobAdminConfig;
import com.xxl.job.admin.core.cron.CronExpression;
import com.xxl.job.admin.core.model.XxlJobInfo;
import com.xxl.job.admin.core.trigger.TriggerTypeEnum;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.text.ParseException;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.TimeUnit;
/**
* @author xuxueli 2019-05-21
*/
public class JobScheduleHelper {
private static Logger logger = LoggerFactory.getLogger(JobScheduleHelper.class);
private static JobScheduleHelper instance = new JobScheduleHelper();
public static JobScheduleHelper getInstance(){
return instance;
}
public static final long PRE_READ_MS = 5000; // pre read
private Thread scheduleThread;
private Thread ringThread;
private volatile boolean scheduleThreadToStop = false;
private volatile boolean ringThreadToStop = false;
private volatile static Map<Integer, List<Integer>> ringData = new ConcurrentHashMap<>();
public void start(){
// schedule thread
scheduleThread = new Thread(new Runnable() {
@Override
public void run() {
try {
TimeUnit.MILLISECONDS.sleep(5000 - System.currentTimeMillis()%1000 );
} catch (InterruptedException e) {
if (!scheduleThreadToStop) {
logger.error(e.getMessage(), e);
}
}
logger.info(">>>>>>>>> init xxl-job admin scheduler success.");
// pre-read count: treadpool-size * trigger-qps (each trigger cost 50ms, qps = 1000/50 = 20)
int preReadCount = (XxlJobAdminConfig.getAdminConfig().getTriggerPoolFastMax() + XxlJobAdminConfig.getAdminConfig().getTriggerPoolSlowMax()) * 20;
while (!scheduleThreadToStop) {
// Scan Job
long start = System.currentTimeMillis();
Connection conn = null;
Boolean connAutoCommit = null;
PreparedStatement preparedStatement = null;
boolean preReadSuc = true;
try {
conn = XxlJobAdminConfig.getAdminConfig().getDataSource().getConnection();
connAutoCommit = conn.getAutoCommit();
conn.setAutoCommit(false);
preparedStatement = conn.prepareStatement( "select * from xxl_job_lock where lock_name = 'schedule_lock' for update" );
preparedStatement.execute();
// tx start
// 1、pre read
long nowTime = System.currentTimeMillis();
List<XxlJobInfo> scheduleList = XxlJobAdminConfig.getAdminConfig().getXxlJobInfoDao().scheduleJobQuery(nowTime + PRE_READ_MS, preReadCount);
if (scheduleList!=null && scheduleList.size()>0) {
// 2、push time-ring
for (XxlJobInfo jobInfo: scheduleList) {
// time-ring jump
if (nowTime > jobInfo.getTriggerNextTime() + PRE_READ_MS) {
// 2.1、trigger-expire > 5s：pass && make next-trigger-time
logger.warn(">>>>>>>>>>> xxl-job, schedule misfire, jobId = " + jobInfo.getId());
// fresh next
refreshNextValidTime(jobInfo, new Date());
} else if (nowTime > jobInfo.getTriggerNextTime()) {
// 2.2、trigger-expire < 5s：direct-trigger && make next-trigger-time
// 1、trigger
JobTriggerPoolHelper.trigger(jobInfo.getId(), TriggerTypeEnum.CRON, -1, null, null, null);
logger.debug(">>>>>>>>>>> xxl-job, schedule push trigger : jobId = " + jobInfo.getId() );
// 2、fresh next
refreshNextValidTime(jobInfo, new Date());
// next-trigger-time in 5s, pre-read again
if (jobInfo.getTriggerStatus()==1 && nowTime + PRE_READ_MS > jobInfo.getTriggerNextTime()) {
// 1、make ring second
int ringSecond = (int)((jobInfo.getTriggerNextTime()/1000)%60);
// 2、push time ring
pushTimeRing(ringSecond, jobInfo.getId());
// 3、fresh next
refreshNextValidTime(jobInfo, new Date(jobInfo.getTriggerNextTime()));
}
} else {
// 2.3、trigger-pre-read：time-ring trigger && make next-trigger-time
// 1、make ring second
int ringSecond = (int)((jobInfo.getTriggerNextTime()/1000)%60);
// 2、push time ring
pushTimeRing(ringSecond, jobInfo.getId());
// 3、fresh next
refreshNextValidTime(jobInfo, new Date(jobInfo.getTriggerNextTime()));
}
}
// 3、update trigger info
for (XxlJobInfo jobInfo: scheduleList) {
XxlJobAdminConfig.getAdminConfig().getXxlJobInfoDao().scheduleUpdate(jobInfo);
}
} else {
preReadSuc = false;
}
// tx stop
} catch (Exception e) {
if (!scheduleThreadToStop) {
logger.error(">>>>>>>>>>> xxl-job, JobScheduleHelper#scheduleThread error:{}", e);
}
} finally {
// commit
if (conn != null) {
try {
conn.commit();
} catch (SQLException e) {
if (!scheduleThreadToStop) {
logger.error(e.getMessage(), e);
}
}
try {
conn.setAutoCommit(connAutoCommit);
} catch (SQLException e) {
if (!scheduleThreadToStop) {
logger.error(e.getMessage(), e);
}
}
try {
conn.close();
} catch (SQLException e) {
if (!scheduleThreadToStop) {
logger.error(e.getMessage(), e);
}
}
}
// close PreparedStatement
if (null != preparedStatement) {
try {
preparedStatement.close();
} catch (SQLException e) {
if (!scheduleThreadToStop) {
logger.error(e.getMessage(), e);
}
}
}
}
long cost = System.currentTimeMillis()-start;
// Wait seconds, align second
if (cost < 1000) { // scan-overtime, not wait
try {
// pre-read period: success > scan each second; fail > skip this period;
TimeUnit.MILLISECONDS.sleep((preReadSuc?1000:PRE_READ_MS) - System.currentTimeMillis()%1000);
} catch (InterruptedException e) {
if (!scheduleThreadToStop) {
logger.error(e.getMessage(), e);
}
}
}
}
logger.info(">>>>>>>>>>> xxl-job, JobScheduleHelper#scheduleThread stop");
}
});
scheduleThread.setDaemon(true);
scheduleThread.setName("xxl-job, admin JobScheduleHelper#scheduleThread");
scheduleThread.start();
// ring thread
ringThread = new Thread(new Runnable() {
@Override
public void run() {
// align second
try {
TimeUnit.MILLISECONDS.sleep(1000 - System.currentTimeMillis()%1000 );
} catch (InterruptedException e) {
if (!ringThreadToStop) {
logger.error(e.getMessage(), e);
}
}
while (!ringThreadToStop) {
try {
// second data
List<Integer> ringItemData = new ArrayList<>();
int nowSecond = Calendar.getInstance().get(Calendar.SECOND); // 避免处理耗时太长，跨过刻度，向前校验一个刻度；
for (int i = 0; i < 2; i++) {
List<Integer> tmpData = ringData.remove( (nowSecond+60-i)%60 );
if (tmpData != null) {
ringItemData.addAll(tmpData);
}
}
// ring trigger
logger.debug(">>>>>>>>>>> xxl-job, time-ring beat : " + nowSecond + " = " + Arrays.asList(ringItemData) );
if (ringItemData.size() > 0) {
// do trigger
for (int jobId: ringItemData) {
// do trigger
JobTriggerPoolHelper.trigger(jobId, TriggerTypeEnum.CRON, -1, null, null, null);
}
// clear
ringItemData.clear();
}
} catch (Exception e) {
if (!ringThreadToStop) {
logger.error(">>>>>>>>>>> xxl-job, JobScheduleHelper#ringThread error:{}", e);
}
}
// next second, align second
try {
TimeUnit.MILLISECONDS.sleep(1000 - System.currentTimeMillis()%1000);
} catch (InterruptedException e) {
if (!ringThreadToStop) {
logger.error(e.getMessage(), e);
}
}
}
logger.info(">>>>>>>>>>> xxl-job, JobScheduleHelper#ringThread stop");
}
});
ringThread.setDaemon(true);
ringThread.setName("xxl-job, admin JobScheduleHelper#ringThread");
ringThread.start();
}
private void refreshNextValidTime(XxlJobInfo jobInfo, Date fromTime) throws ParseException {
Date nextValidTime = new CronExpression(jobInfo.getJobCron()).getNextValidTimeAfter(fromTime);
if (nextValidTime != null) {
jobInfo.setTriggerLastTime(jobInfo.getTriggerNextTime());
jobInfo.setTriggerNextTime(nextValidTime.getTime());
} else {
jobInfo.setTriggerStatus(0);
jobInfo.setTriggerLastTime(0);
jobInfo.setTriggerNextTime(0);
}
}
private void pushTimeRing(int ringSecond, int jobId){
// push async ring
List<Integer> ringItemData = ringData.get(ringSecond);
if (ringItemData == null) {
ringItemData = new ArrayList<Integer>();
ringData.put(ringSecond, ringItemData);
}
ringItemData.add(jobId);
logger.debug(">>>>>>>>>>> xxl-job, schedule push time-ring : " + ringSecond + " = " + Arrays.asList(ringItemData) );
}
public void toStop(){
// 1、stop schedule
scheduleThreadToStop = true;
try {
TimeUnit.SECONDS.sleep(1); // wait
} catch (InterruptedException e) {
logger.error(e.getMessage(), e);
}
if (scheduleThread.getState() != Thread.State.TERMINATED){
// interrupt and wait
scheduleThread.interrupt();
try {
scheduleThread.join();
} catch (InterruptedException e) {
logger.error(e.getMessage(), e);
}
}
// if has ring data
boolean hasRingData = false;
if (!ringData.isEmpty()) {
for (int second : ringData.keySet()) {
List<Integer> tmpData = ringData.get(second);
if (tmpData!=null && tmpData.size()>0) {
hasRingData = true;
break;
}
}
}
if (hasRingData) {
try {
TimeUnit.SECONDS.sleep(8);
} catch (InterruptedException e) {
logger.error(e.getMessage(), e);
}
}
// stop ring (wait job-in-memory stop)
ringThreadToStop = true;
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
logger.error(e.getMessage(), e);
}
if (ringThread.getState() != Thread.State.TERMINATED){
// interrupt and wait
ringThread.interrupt();
try {
ringThread.join();
} catch (InterruptedException e) {
logger.error(e.getMessage(), e);
}
}
logger.info(">>>>>>>>>>> xxl-job, JobScheduleHelper stop");
}
}