读写锁样例

来源：互联网发布：spring 获取端口号编辑：程序博客网时间：2024/06/06 00:32

package thread.lock;public class Test {    public static void main(String[] args) {        final Printer printer = new Printer();        Thread thread1 = new Thread(){            @Override            public void run() {                printer.read("thread1 read...");                printer.write("thread1 write...");            }        };        Thread thread2 = new Thread(){            @Override            public void run() {                printer.read("thread2 read...");                printer.write("thread2 write...");            }        };        thread1.start();        thread2.start();    }}

package thread.lock;import java.util.concurrent.locks.ReadWriteLock;import java.util.concurrent.locks.ReentrantReadWriteLock;public class Printer {    ReadWriteLock lock = new ReentrantReadWriteLock();    /**     * 读操作     * @author JIANGBIN     * @param str     */    public void read(String str){        lock.readLock().lock();//读锁1        try{            for (int i = 0; i < 3; i++) {                try {                    System.out.println(str);                    Thread.sleep(200);//暂停100ms，不释放锁，以便更好的观察输出结果                } catch (InterruptedException e) {                }            }        }finally{            lock.readLock().unlock();//解锁，要放在finnall块里面        }    }    /**     * 写操作     * @author JIANGBIN     * @param str     */    public void write(String str){        lock.writeLock().lock();//写锁        try{for (int i = 0; i < 3; i++) {            try {                System.out.println(str);                Thread.sleep(100);//暂停100ms，不释放锁，以便更好的观察输出结果            } catch (InterruptedException e) {            }        }        }finally{            lock.writeLock().unlock();//解锁        }    }}

输出结果：

thread1 read...thread2 read...thread2 read...thread1 read...thread2 read...thread1 read...thread2 write...thread2 write...thread2 write...thread1 write...thread1 write...thread1 write...

总结：读锁之间可以变法访问，读锁和写锁直接互斥，写锁和写锁之间互斥

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