我在启动线程时有以下方法测试:
public static void main(String[] args) throws InterruptedException {
List<Thread> threads = new ArrayList<>();
final CyclicBarrier cyclicBarrier = new CyclicBarrier(1);
Thread thread = new Thread(new CallbackThread(cyclicBarrier, threads));
threads.add(thread);
thread.start();
}
回调线程如下所示:
class CallbackThread implements Runnable {
CyclicBarrier cyclicBarrier;
List<Thread> threads;
CallbackThread(CyclicBarrier cyclicBarrier, List<Thread> threads) {
this.cyclicBarrier = cyclicBarrier;
this.threads = threads;
}
@Override
public void run() {
try {
cyclicBarrier.await();
} catch (InterruptedException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch (BrokenBarrierException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
}
System.out.println("Threads started");
for (Thread thread1 : threads) {
try {
thread1.join();
} catch (InterruptedException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
}
}
System.out.println("Threads finished");
}
}
当我运行应用程序时,我看到以下输出:
Threads started
并且应用程序挂起。
我不明白为什么。
如果将连接逻辑替换为主方法 - 一切都很好。
public static void main(String[] args) throws InterruptedException {
List<Thread> threads = new ArrayList<>();
final CyclicBarrier cyclicBarrier = new CyclicBarrier(1);
Thread thread = new Thread(new CallbackThread(cyclicBarrier, threads));
threads.add(thread);
thread.start();
for (Thread thread1 : threads) {
try {
thread1.join();
} catch (InterruptedException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
}
}
System.out.println("Threads finished");
}
你能解释一下这种差异吗?
恕我直言,它应该工作相同。
最佳答案
第一个示例中的代码在其自己的线程上调用 join。您将其添加到列表中,线程会迭代列表并连接列表中的每个线程。
关于java - 当我在 CyclicBarrier 回调中调用 join 时,应用程序挂起,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/31913718/