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<bean  id="quartzExceptionSchedulerListener"  class="com.***.crm.quartz.listener.QuartzExceptionSchedulerListener"></bean>
<!-- 配置器 -->
<property name="schedulerListeners">
 	<list>
 		<ref bean="quartzExceptionSchedulerListener"/>
 	</list>
</property>

quartz与线程

主处理线程：QuartzSchedulerThread

启动Scheduler时。QuartzScheduler被创建并创建一个org.quartz.core.QuartzSchedulerThread 类的实例。

QuartzSchedulerThread 包含有决定何时下一个Job将被触发的处理循环。QuartzSchedulerThread 是一个 Java 线程。它作为一个非守护线程运行在正常优先级下。

QuartzSchedulerThread 的主处理轮循步骤：

1. 当 Scheduler 正在运行时：

A. 检查是否有转换为 standby 模式的请求。

1. 假如 standby 方法被调用，等待继续的信号

B. 询问 JobStore 下次要被触发的 Trigger.

1. 如果没有 Trigger 待触发，等候一小段时间后再次检查

2. 假如有一个可用的 Trigger，等待触发它的确切时间的到来

D. 时间到了，为 Trigger 获取到 triggerFiredBundle.

E. 使用Scheduler和triggerFiredBundle 为 Job 创建一个JobRunShell实例

F. 在ThreadPool 申请一个线程运行 JobRunShell 实例.

代码逻辑在QuartzSchedulerThread 的 run() 中,如下:

	/**
	 * QuartzSchedulerThread.run
     * <p>
     * The main processing loop of the <code>QuartzSchedulerThread</code>.
     * </p>
     */
    public void run() {
        boolean lastAcquireFailed = false;
        while (!halted.get()) {
            try {
                // check if we're supposed to pause...
                synchronized (si) {
                    while (paused && !halted.get()) {
                        try {
                            // wait until togglePause(false) is called...
                            si.wait(1000L);
                        } catch (InterruptedException ignore) {
                        }
                    }
    
                    if (halted.get()) {
                        break;
                    }
                }

                int availTreadCount = qsRsrcs.getThreadPool().blockForAvailableThreads();
                if(availTreadCount > 0) { // will always be true, due to semantics of blockForAvailableThreads...
                    Trigger trigger = null;

                    long now = System.currentTimeMillis();
                    clearSignaledSchengChange();
                    try {
                        trigger = qsRsrcs.getJobStore().acquireNextTrigger(
                                ctxt, now + idleWaitTime);
                        lastAcquireFailed = false;
                    } catch (JobPersistenceException jpe) {
                        if(!lastAcquireFailed) {
                            qs.notifySchedulerListenersError(
                                "An error occured while scanning for the next trigger to fire.",
                                jpe);
                        }
                        lastAcquireFailed = true;
                    } catch (RuntimeException e) {
                        if(!lastAcquireFailed) {
                            getLog().error("quartzSchedulerThreadLoop: RuntimeException "
                                    +e.getMessage(), e);
                        }
                        lastAcquireFailed = true;
                    }

                    if (trigger != null) {
                        now = System.currentTimeMillis();
                        long triggerTime = trigger.getNextFireTime().getTime();
                        long timeUntilTrigger = triggerTime - now;
                        while(timeUntilTrigger > 2) {
	                        synchronized(si) {
	                            if(!isCandidateNewTimeEarlierWithinReason(triggerTime, false)) {
    		                        try {
    		                        	// we could have blocked a long while
    		                        	// on 'synchronize', so we must recompute
    		                        	now = System.currentTimeMillis();
    		                            timeUntilTrigger = triggerTime - now;
    		                            if(timeUntilTrigger >= 1)
    		                            	si.wait(timeUntilTrigger);
    		                        } catch (InterruptedException ignore) {
    		                        }
	                            }
	                        }		                        
	                        if(releaseIfScheduleChangedSignificantly(trigger, triggerTime)) {
	                            trigger = null;
	                            break;
	                        }
	                        now = System.currentTimeMillis();
	                        timeUntilTrigger = triggerTime - now;
                        }
                        if(trigger == null)
                        	continue;
                        
                        // set trigger to 'executing'
                        TriggerFiredBundle bndle = null;

                        boolean goAhead = true;
                        synchronized(si) {
                        	goAhead = !halted.get();
                        }

                        if(goAhead) {
                            try {
                                bndle = qsRsrcs.getJobStore().triggerFired(ctxt,
                                        trigger);
                            } catch (SchedulerException se) {
                                qs.notifySchedulerListenersError(
                                        "An error occured while firing trigger '"
                                                + trigger.getFullName() + "'", se);
                            } catch (RuntimeException e) {
                                getLog().error(
                                    "RuntimeException while firing trigger " +
                                    trigger.getFullName(), e);
                                // db connection must have failed... keep
                                // retrying until it's up...
                                releaseTriggerRetryLoop(trigger);
                            }
                        }
                        
                        // it's possible to get 'null' if the trigger was paused,
                        // blocked, or other similar occurrences that prevent it being
                        // fired at this time...  or if the scheduler was shutdown (halted)
                        if (bndle == null) {
                            try {
                                qsRsrcs.getJobStore().releaseAcquiredTrigger(ctxt,
                                        trigger);
                            } catch (SchedulerException se) {
                                qs.notifySchedulerListenersError(
                                        "An error occured while releasing trigger '"
                                                + trigger.getFullName() + "'", se);
                                // db connection must have failed... keep retrying
                                // until it's up...
                                releaseTriggerRetryLoop(trigger);
                            }
                            continue;
                        }

                        // TODO: improvements:
                        //
                        // 2- make sure we can get a job runshell before firing trigger, or
                        //   don't let that throw an exception (right now it never does,
                        //   but the signature says it can).
                        // 3- acquire more triggers at a time (based on num threads available?)
                        JobRunShell shell = null;
                        try {
                            shell = qsRsrcs.getJobRunShellFactory().borrowJobRunShell();
                            shell.initialize(qs, bndle);
                        } catch (SchedulerException se) {
                            try {
                                qsRsrcs.getJobStore().triggeredJobComplete(ctxt,
                                        trigger, bndle.getJobDetail(), Trigger.INSTRUCTION_SET_ALL_JOB_TRIGGERS_ERROR);
                            } catch (SchedulerException se2) {
                                qs.notifySchedulerListenersError(
                                        "An error occured while placing job's triggers in error state '"
                                                + trigger.getFullName() + "'", se2);
                                // db connection must have failed... keep retrying
                                // until it's up...
                                errorTriggerRetryLoop(bndle);
                            }
                            continue;
                        }

                        if (qsRsrcs.getThreadPool().runInThread(shell) == false) {
                            try {
                                // this case should never happen, as it is indicative of the
                                // scheduler being shutdown or a bug in the thread pool or
                                // a thread pool being used concurrently - which the docs
                                // say not to do...
                                getLog().error("ThreadPool.runInThread() return false!");
                                qsRsrcs.getJobStore().triggeredJobComplete(ctxt,
                                        trigger, bndle.getJobDetail(), Trigger.INSTRUCTION_SET_ALL_JOB_TRIGGERS_ERROR);
                            } catch (SchedulerException se2) {
                                qs.notifySchedulerListenersError(
                                        "An error occured while placing job's triggers in error state '"
                                                + trigger.getFullName() + "'", se2);
                                // db connection must have failed... keep retrying
                                // until it's up...
                                releaseTriggerRetryLoop(trigger);
                            }
                        }
                        continue;
                    }
                } else { // if(availTreadCount > 0)
                    continue; // should never happen, if threadPool.blockForAvailableThreads() follows contract
                }

                long now = System.currentTimeMillis();
                long waitTime = now + getRandomizedIdleWaitTime();
                long timeUntilContinue = waitTime - now;
                synchronized(si) {
                	try {
						si.wait(timeUntilContinue);
					} catch (InterruptedException ignore) {
					}
                }

            } catch(RuntimeException re) {
                getLog().error("Runtime error occured in main trigger firing loop.", re);
            }
        } // loop...

        // drop references to scheduler stuff to aid garbage collection...
        qs = null;
        qsRsrcs = null;
    }

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