Async::Barrier#waitnow returns the number of tasks that were waited for, ornilif there were no tasks to wait for. This provides better feedback about the operation, and allows you to know how many tasks were involved in the wait.
Async::Barrier#wait now returns the number of tasks that were waited for, or nil if there were no tasks to wait for. This provides better feedback about the operation, and allows you to know how many tasks were involved in the wait.