Executors: How to synchronously wait until all tasks have finished if tasks are created recursively?

Question

My question is strongly related to this one here. As was posted there, I would like the main thread to wait until the work queue is empty and all tasks have finished. The pr

Answer 1

Why don't you use a counter? For example:

private AtomicInteger counter = new AtomicInteger(0);

and increment the counter by one just before submitting the task to the queue:

counter.incrementAndGet();

and decrement it by one at the end of the task:

counter.decrementAndGet();

and the check would be something like:

// ...
while (counter.get() > 0);