2017-10-17 130 views
-2

代码:的Java ScheduledExecutorService的给奇怪的结果

import java.util.concurrent.Executors; 
import java.util.concurrent.ScheduledExecutorService; 
import java.util.concurrent.TimeUnit; 

public class Test implements Runnable { 

    private Integer xyz = 1; 

    public static void main(String[] args) throws InterruptedException { 
     ScheduledExecutorService executorService = Executors.newScheduledThreadPool(2); 

     Test test = new Test(); 
     test.xyz = 20; 

     Test test2 = new Test(); 

     System.out.println("Values of xyz = " + test.xyz + " , " + test2.xyz); 

     executorService.scheduleWithFixedDelay(test, 100, 1000, TimeUnit.MILLISECONDS); 
     executorService.scheduleWithFixedDelay(test2, 100, 100, TimeUnit.MILLISECONDS); 
     executorService.awaitTermination(3000, TimeUnit.MILLISECONDS); 
     executorService.shutdown(); 
    } 

    @Override 
    public void run() { 
     this.xyz += (int) Thread.currentThread().getId(); 
     System.out.println(Thread.currentThread().getId() + " " + this.xyz); 
    } 
} 

输出:

Values of xyz = 
20 1 | 
10 30 | 
11 12 | 
11 23 | 
11 34 | 
11 45 | 
11 56 | 
11 67 | 
11 78 | 
11 89 | 
11 100 | 
11 111 | 
10 40 | 
11 122 | 
11 133 | 
11 144 | 
11 155 | 
11 166 | 
11 177 | 
11 188 | 
11 199 | 
11 210 | 
11 221 | 
10 50 | 
11 232 | 
11 243 | 
11 254 | 
11 265 | 
10 275 | (10 should have been 60 here) 
10 285 | 
10 295 | 
10 305 | 
10 315 | 
+3

'test'运行3次,'test2'在2个不同的线程上执行。那里没有什么令人惊讶的。你为什么期望60? – assylias

+0

我错过了一些关于ScheduledExecutorService的上下文,我想不。的任务等于没有。 threadPool大小。不知道他们是在多个线程中执行以满足费率要求。 - 谢谢 –

回答

1

ScheduledExecutorService的使用分配给运行在指定的速度提交的任务线程。误解是每个线程都与1个任务相关联,仅用于以指定的频率运行该特定任务。但事实并非如此,所以这是有道理的。