9. xxl-job原理-- jobthread的作用

xxl-job: v2.0.2 原理 目录学习

• 0. xxl-job原理
• 1. xxl-job原理—定时任务架构
• 2. xxl-job原理-- 调度中心
• 3. xxl-job原理-- 执行器注册
• 4. xxl-job原理-- 执行器注册问题
• 5 xxl-job原理-- 执行器注册问题
• 6. xxl-job 原理-- 调度中心注册
• 7. xxl-job 原理-- 任务管理
• 8. xxl-job 原理-- 任务执行或触发
• 9. xxl-job原理-- jobthread的作用
• 10. xxl-job原理—回调

jobthread

位于： xxl-job-core包中

源代码

private int jobId;  // job的id
private IJobHandler handler;  job的执行器
private LinkedBlockingQueue triggerQueue; // job的队列
private Set triggerLogIdSet;		// avoid repeat trigger for the same TRIGGER_LOG_ID  防止重复触发
private volatile boolean toStop = false; 共享变量用于停止线程
private String stopReason;   停止原因
private boolean running = false;    // if running job   job的运行状态
private int idleTimes = 0;			// idel times  空闲时间

start运行

@Override
	public void run() {

    	// init
    	try {
			handler.init();
		} catch (Throwable e) {
    		logger.error(e.getMessage(), e);
		}

		// execute
		while(!toStop){
			running = false;
			idleTimes++;

            TriggerParam triggerParam = null;
            ReturnT executeResult = null;
            try {
				// to check toStop signal, we need cycle, so wo cannot use queue.take(), instand of poll(timeout)
取出 队列
				triggerParam = triggerQueue.poll(3L, TimeUnit.SECONDS);
				if (triggerParam!=null) {
					running = true;
					idleTimes = 0;
移除triggerLogIdSet记录
					triggerLogIdSet.remove(triggerParam.getLogId());

					// log filename, like "logPath/yyyy-MM-dd/9999.log"
					String logFileName = XxlJobFileAppender.makeLogFileName(new Date(triggerParam.getLogDateTim()), triggerParam.getLogId());
					XxlJobFileAppender.contextHolder.set(logFileName);
					ShardingUtil.setShardingVo(new ShardingUtil.ShardingVO(triggerParam.getBroadcastIndex(), triggerParam.getBroadcastTotal()));

					// execute  
					XxlJobLogger.log("
----------- xxl-job job execute start -----------
----------- Param:" + triggerParam.getExecutorParams());

					if (triggerParam.getExecutorTimeout() > 0) {
						// limit timeout
						Thread futureThread = null;
						try {
							final TriggerParam triggerParamTmp = triggerParam;

							FutureTask> futureTask = new FutureTask>(new Callable>() {
								@Override
								public ReturnT call() throws Exception {
//定义执行方法
									return handler.execute(triggerParamTmp.getExecutorParams());
								}
							});
							futureThread = new Thread(futureTask);
// 开始执行
							futureThread.start();
// 返回执行结果
							executeResult = futureTask.get(triggerParam.getExecutorTimeout(), TimeUnit.SECONDS);
						} catch (TimeoutException e) {

							XxlJobLogger.log("
----------- xxl-job job execute timeout");
							XxlJobLogger.log(e);

							executeResult = new ReturnT(IJobHandler.FAIL_TIMEOUT.getCode(), "job execute timeout ");
						} finally {
							futureThread.interrupt();
						}
					} else {
						// just execute  执行一次
						executeResult = handler.execute(triggerParam.getExecutorParams());
					}

					if (executeResult == null) {
						executeResult = IJobHandler.FAIL;
					} else {
						executeResult.setMsg(
								(executeResult!=null&&executeResult.getMsg()!=null&&executeResult.getMsg().length()>50000)
										?executeResult.getMsg().substring(0, 50000).concat("...")
										:executeResult.getMsg());
						executeResult.setContent(null);	// limit obj size
					}
					XxlJobLogger.log("
----------- xxl-job job execute end(finish) -----------
----------- ReturnT:" + executeResult);

				} else {
					if (idleTimes > 30) {
						XxlJobExecutor.removeJobThread(jobId, "excutor idel times over limit.");
					}
				}
			} catch (Throwable e) {
				if (toStop) {
					XxlJobLogger.log("
----------- JobThread toStop, stopReason:" + stopReason);
				}

				StringWriter stringWriter = new StringWriter();
				e.printStackTrace(new PrintWriter(stringWriter));
				String errorMsg = stringWriter.toString();
				executeResult = new ReturnT(ReturnT.FAIL_CODE, errorMsg);

				XxlJobLogger.log("
----------- JobThread Exception:" + errorMsg + "
----------- xxl-job job execute end(error) -----------");
			} finally {
                if(triggerParam != null) {
                    // callback handler info
                    if (!toStop) {
                        // commonm
                        TriggerCallbackThread.pushCallBack(new HandleCallbackParam(triggerParam.getLogId(), triggerParam.getLogDateTim(), executeResult));
                    } else {
                        // is killed
                        ReturnT stopResult = new ReturnT(ReturnT.FAIL_CODE, stopReason + " [job running，killed]");
                        TriggerCallbackThread.pushCallBack(new HandleCallbackParam(triggerParam.getLogId(), triggerParam.getLogDateTim(), stopResult));
                    }
                }
            }
        }

		// callback trigger request in queue
		while(triggerQueue !=null && triggerQueue.size()>0){
			TriggerParam triggerParam = triggerQueue.poll();
			if (triggerParam!=null) {
				// is killed
				ReturnT stopResult = new ReturnT(ReturnT.FAIL_CODE, stopReason + " [job not executed, in the job queue, killed.]");
				TriggerCallbackThread.pushCallBack(new HandleCallbackParam(triggerParam.getLogId(), triggerParam.getLogDateTim(), stopResult));
			}
		}

		// destroy
		try {
			handler.destroy();
		} catch (Throwable e) {
			logger.error(e.getMessage(), e);
		}

		logger.info(">>>>>>>>>>> xxl-job JobThread stoped, hashCode:{}", Thread.currentThread());
	}

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