You can only use Thread.join if you’re handling the threads yourself. Most people choose not to deal with the minutia of thread handling directly, and instead use an ExecutorService to handle it for them. ExecutorServices do not directly reveal how they are executing tasks, so you would have to use a CountDownLatch: (Assuming you don’t … Read more
CountDownLatch is frequently used for the exact opposite of your example. Generally, you would have many threads blocking on await() that would all start simultaneously when the countown reached zero. final CountDownLatch countdown = new CountDownLatch(1); for (int i = 0; i < 10; ++ i) { Thread racecar = new Thread() { public void … Read more
There’s another difference. When using a CyclicBarrier, the assumption is that you specify the number of waiting threads that trigger the barrier. If you specify 5, you must have at least 5 threads to call await(). When using a CountDownLatch, you specify the number of calls to countDown() that will result in all waiting threads … Read more
Yes, you understood correctly. CountDownLatch works in latch principle, the main thread will wait until the gate is open. One thread waits for n threads, specified while creating the CountDownLatch. Any thread, usually the main thread of the application, which calls CountDownLatch.await() will wait until count reaches zero or it’s interrupted by another thread. All … Read more