多线程中加了锁还是不能杜绝其他线程进入加锁的代码块..... - 黑马程序员技术交流社区

package test11;
package test11;
/*题目1：编写一个多线程程序，每隔30ms输出线程的名字（线程至少3个以上）【多线程】。
*/
public class ThreadTest {
public static void main(String[] args) {
TimeMillis tm=new TimeMillis();
MyThread mt1=new MyThread(tm);
MyThread mt2=new MyThread(tm);
MyThread mt3=new MyThread(tm);
MyThread mt4=new MyThread(tm);
MyThread mt5=new MyThread(tm);
new Thread(mt1).start();
new Thread(mt2).start();
new Thread(mt3).start();
new Thread(mt4).start();
new Thread(mt5).start();
}
}
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class TimeMillis {
//创建对象时初始化属性t，获取系统时间要使用同步
private long t=System.currentTimeMillis();
private int count=0;
private Lock lock=new ReentrantLock();
private Condition con=lock.newCondition();
private boolean flag;
private int x=1;
void getTime() throws InterruptedException{
lock.lock();
try{
while(flag){
con.await();
}
flag=true;
//线程执行时获取系统时间
long t1= System.currentTimeMillis();
//判断线程执行时的系统时间和对象初始化的系统时间差值是否是30的整数倍，是就打印线程名
if(((t1-t)/30)>=x){
x++;
count++;
System.out.println(t1);
System.out.println(Thread.currentThread().getName()+"第"+count+"次"+(t1-t));
}
flag=false;
con.signal();
}finally{
lock.unlock();
}
}
}
package test11;
public class MyThread implements Runnable {
private TimeMillis tm;
MyThread(TimeMillis tm){
this.tm=tm;
}
//线程的执行语句
public void run() {
int x=0;
while(x<10000){
x++;
try {
tm.getTime();
} catch (Exception e) {
System.out.println("线程异常中断");
}
}
}
}

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