java 同步信号量使用方法

Myth丶恋晨 2023-07-25 12:49 27阅读 0赞

#  java 同步信号量 使用方法 #

其中核心是 同步信号量初始设置值为0，消费者取值的时候就挂起，只有生产者生产后，才会release同步信号量，

同步信号量才能进行操作。

import java.util.concurrent.Semaphore;
    
    public class test {
        int count = 0;
        final Semaphore synSem = new Semaphore(0);
        final Semaphore mutex = new Semaphore(1);
    
        public static void main(String[] args) {
            test t = new test();
            new Thread(t.new Producer()).start();
            new Thread(t.new Consumer()).start();
    
        }
    
        class Producer implements Runnable {
            @Override
            public void run() {
                for (int i = 0; i < 3; i++) {
                    try {
                        Thread.sleep(1000);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    try {
                        mutex.acquire();
                        count++;
                        System.out.println("生产者" + Thread.currentThread().getName()
                                + "已生产完成，商品数量：" + count);
                        mutex.release();
                    } catch (Exception e) {
                        e.printStackTrace();
                    } finally {
                        synSem.release();
                    }
    
                }
            }
        }
    
        class Consumer implements Runnable {
    
            @Override
            public void run() {
    
                while (true) {
                    try {
                        synSem.acquire();// 注意顺序
                        for (int i = 0; i < 5; i++) {
                            mutex.acquire();
                            count--;
                            System.out.println("消费者" + Thread.currentThread().getName()
                                    + "已消费，剩余商品数量：" + count);
                            mutex.release();
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                    } finally {
                    }
                }
            }
        }
    }