2个线程轮流输出
A、B两个线程轮流输出1~100的数字
A线程输出: 1、3、5…47、49、 52、54…98、100
B线程输出: 2、4、6…48、50、51、53、55…97、99 两个线程输出个数相同
分析：
- 每个线程持有一把锁，运行时，首先获取自己的锁，运行完释放另一个线程的锁
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| import java.util.concurrent.Semaphore;
public class RunningInTurn {
static class Worker extends Thread {
private final String name;
private final Semaphore thisSemaphore;
private final Semaphore nextSemaphore;
private int value;
public Worker(String name, Semaphore thisSemaphore, Semaphore nextSemaphore, int initialValue) {
this.name = name;
this.thisSemaphore = thisSemaphore;
this.nextSemaphore = nextSemaphore;
this.value = initialValue;
}
@Override
public void run() {
int cnt = 0;
while (value <= 100) {
try {
thisSemaphore.acquire();
System.out.println(name + ":\t" + value);
cnt++;
if (value == 50) {
value = 51;
System.out.println(name + ":\t" + value);
cnt++;
value += 2;
} else if (value == 49) {
value = 52;
} else {
value += 2;
}
nextSemaphore.release();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println(name + " cnt : " + cnt);
}
}
public static void main(String[] args) throws InterruptedException {
Semaphore aSemaphore = new Semaphore(1);
Semaphore bSemaphore = new Semaphore(1);
Worker workerA = new Worker("a", aSemaphore, bSemaphore, 1);
Worker workerB = new Worker("b", bSemaphore, aSemaphore, 2);
bSemaphore.acquire();
workerA.start();
workerB.start();
}
}
|