CountDownlatch

CountDownLatch是Java中的一个同步工具类，它可以用于控制多个线程的执行顺序。CountDownLatch内部维护了一个计数器，当计数器的值变为0时，所有等待的线程将被唤醒。

CountDownLatch的主要方法有两个：
1. `countDown()`：每次调用该方法，计数器的值减1。
2. `await()`：调用该方法的线程会被阻塞，直到计数器的值变为0。

使用CountDownLatch可以实现一些并发场景，例如等待多个线程完成某个任务后再继续执行下一步操作。在这种情况下，可以创建一个CountDownLatch对象，并将计数器初始化为等待的线程数量。每个线程完成任务后，调用`countDown()`方法来减少计数器的值。当所有线程都完成任务时，计数器的值变为0，等待的线程将被唤醒，可以继续执行后续操作。

相关问题

countdownlatch

CountDownLatch是Java中的一个工具类，它可以让一个或多个线程等待一组操作完成。CountDownLatch的构造函数会接收一个计数器，当计数器的值为0时，等待线程就会被唤醒。线程可以通过调用CountDownLatch的await()方法来等待计数器的值为0，也可以通过调用CountDownLatch的countDown()方法来减少计数器的值。一般情况下，CountDownLatch被用来协调多个线程之间的操作，例如等待多个线程完成某项任务后再继续执行。

countDownLatch

CountDownLatch is a synchronization tool in Java that allows one or more threads to wait for the completion of a set of operations performed by other threads. It is a type of barrier that blocks the progress of the calling thread until the count reaches zero.

The CountDownLatch class has a constructor that takes an integer value representing the number of times the countDown() method must be invoked before the waiting threads can proceed. The countDown() method decrements the count by one, and the await() method blocks the calling thread until the count reaches zero.

CountDownLatch is often used to coordinate the execution of multiple threads in a concurrent program. For example, a main thread can wait for several worker threads to complete their tasks before continuing with the execution of the program.