9. xxl-job原理--执行器 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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