CountDownLatch和CyclicBarrier的比较

冷不防 2022-12-09 02:53 136阅读 0赞

# CountDownLatch和CyclicBarrier的比较 #

*  CountDownLatch是线程组之间的等待，即一个(或多个)线程等待N个线程完成某件事情之后再执行；而CyclicBarrier则是线程组内的等待，即每个线程相互等待，即N个线程都被拦截之后，然后依次执行。
 *  CountDownLatch是减计数方式，而CyclicBarrier是加计数方式。
 *  CountDownLatch计数为0无法重置，而CyclicBarrier计数达到初始值，则可以重置。
 *  CountDownLatch不可以复用，而CyclicBarrier可以复用。

# CountDownLatch #

package thread;
    
    import java.util.concurrent.CountDownLatch;
    
    public class CountDownLatchDemo { 
        public static void main(String[] args) throws InterruptedException { 
            leaveClassroom();
            county();
        }
    
        private static void county() throws InterruptedException { 
            CountDownLatch countDownLatch=new CountDownLatch(6);
            for (int i = 1; i <=6 ; i++) { 
                new Thread(()->{ 
                    System.out.println(Thread.currentThread().getName()+"\t 国被灭");
                    countDownLatch.countDown();
                }, CountryEnum.list(i).getRetMsg()).start();
            }
            countDownLatch.await();
            System.out.println(Thread.currentThread().getName()+"\t ******秦国一统华夏");
        }
    
        private static void leaveClassroom() throws InterruptedException { 
            CountDownLatch countDownLatch=new CountDownLatch(6);
            for (int i = 1; i <=6 ; i++) { 
                new Thread(()->{ 
                    System.out.println(Thread.currentThread().getName()+"\t上完自习，离开教室");
                    countDownLatch.countDown();
                },String.valueOf(i)).start();
            }
            countDownLatch.await();
            System.out.println(Thread.currentThread().getName()+"\t ******班长最后关门走人");
        }
    }

# CyclicBarrier #

package thread;
    
    import java.util.concurrent.CyclicBarrier;
    
    public class CyclicBarrierDemo { 
        public static void main(String[] args) { 
            CyclicBarrier cyclicBarrier=new CyclicBarrier(7,()->{ 
                System.out.println("*****召唤神龙");
            });
            for (int i = 1; i <=7 ; i++) { 
                final int tempInt=i;
                new Thread(()->{ 
                    System.out.println(Thread.currentThread().getName()+
                            "\t 收集到第"+tempInt+"颗龙珠");
                    try{ 
                        cyclicBarrier.await();
                    }catch (Exception e){ 
                        e.printStackTrace();
                    }
                },String.valueOf(i)).start();
            }
        }
    }

# 参考 #

[java并发编程之三–CyclicBarrier的使用][java_CyclicBarrier]

[java_CyclicBarrier]: https://www.cnblogs.com/brokencolor/p/9752941.html