java - 一个应用程序中的两个单例 - 都具有不同的 @Scheduled 方法 - 一个类方法等待另一个？

Question

以下代码复制了该问题。

测试A类:

package main.java.monitor;

import javax.ejb.Schedule;
import javax.ejb.Singleton;

@Singleton
public class TestA {

    @Schedule(hour="*", minute="*", second="*")
    public void run() {
        System.out.println("Test A started");
        System.out.println("Test A finished");
    }

}

测试B类:

package main.java.monitor;

import javax.ejb.Schedule;
import javax.ejb.Singleton;

@Singleton
public class TestB {

    @Schedule(hour="*", minute="*", second="*")
    public void run() throws InterruptedException {
        System.out.println("Test B started");
        Thread.sleep(10000);
        System.out.println("Test B finished");
    }

}

预期输出(类似)将是测试 A 开始、测试 A 完成的频率是测试 B 开始和测试 B 完成的 10 倍，但实际输出是(添加日期/时间):

Test A started Tue Feb 03 13:09:47 GMT 2015
Test A finished Tue Feb 03 13:09:47 GMT 2015
Test B started Tue Feb 03 13:09:47 GMT 2015
Test A started Tue Feb 03 13:09:48 GMT 2015
Test A finished Tue Feb 03 13:09:48 GMT 2015
Test A started Tue Feb 03 13:09:49 GMT 2015
Test A finished Tue Feb 03 13:09:49 GMT 2015
Test B finished Tue Feb 03 13:09:57 GMT 2015
Test B started Tue Feb 03 13:09:57 GMT 2015
Test A started Tue Feb 03 13:09:58 GMT 2015
Test A finished Tue Feb 03 13:09:58 GMT 2015
Test B finished Tue Feb 03 13:10:07 GMT 2015
Test B started Tue Feb 03 13:10:07 GMT 2015
Test A started Tue Feb 03 13:10:08 GMT 2015
Test A finished Tue Feb 03 13:10:08 GMT 2015

有谁能解释一下吗？

提前致谢

Answer 1

我想您会很清楚地在 EJB 上添加 @AccessTimeout(0)

用2个字来说:默认情况下，单例是@Lock(WRITE)，B正在锁定(每秒执行一次，但等待10)。一旦异步池已满(默认为 3 个线程)，则不再有可用线程，并且调用正在等待 B 释放一个槽。