Question

I have a consumer thread taking elements from a LinkedBlockingQueue, and I make it sleep manually when it’s empty. I use peek() to see if the queue empty because I have to do stuff before sending the thread to sleep, and I do that with queue.wait().

---

So, when I’m in another thread and add()an element to the queue, does that automatically notify the thread that was wait()ing on the queue?

Answer 1

Yes it does. Or rather, it does using a more-efficient internal lock object and not the outer queue object’s lock; if you want to sleep until something arrives in the queue, do a blocking take(). (If you have other things to do while waiting, consider whether a blocking queue is the correct way of receiving messages from elsewhere.)