多个人过门引出线程安全问题

门

package com.dwz.concurrency2.chapter6;
/**
 * SharedResource
 */
public class Gate {
    private int counter = 0;
    private String name = "Nobody";
    private String address = "Nowhere";
    /**
     * 临界值
     * @param name
     * @param address
     * synchronized
     * 
     * 将数据的读写都加在一个锁里面，极大影响程序执行效率，怎样优化？
     */
    public void pass(String name, String address) {
        this.counter++;
        /*race*/
        this.name = name;
        this.address = address;
        verify();
    }
    
    public void verify() {
        if(this.name.charAt(0) != this.address.charAt(0)) {
            System.out.println("***********BROKEN*************" + toString());
        }
    }
    
    @Override
    public String toString() {
        return "No." + counter + ":" + name + "," + address;
    }
}

过门人

package com.dwz.concurrency2.chapter6;

public class User extends Thread {
    private final String myName;
    private final String myAddress;
    private final Gate gate;
    
    public User(String myName, String myAddress, Gate gate) {
        super();
        this.myName = myName;
        this.myAddress = myAddress;
        this.gate = gate;
    }
    
    @Override
    public void run() {
        System.out.println(myName + " BEGIN");
        while(true) {
            this.gate.pass(myName, myAddress);
        }
    }
}

测试代码

package com.dwz.concurrency2.chapter6;

public class Client {
    public static void main(String[] args) {
        Gate gate = new Gate();
        User bj = new User("beilao", "beijing", gate);
        User sh = new User("shanglao", "shanghai", gate);
        User gz = new User("guanglao", "guangzhou", gate);
        
        bj.start();
        sh.start();
        gz.start();
    }
}

测试结果：不是线程安全的，当pass()上加synchronized时线程安全

但是将数据的读写都加在一个锁里面，极大影响程序执行效率，怎样优化？