class Async::Semaphore

@parameter limit [Integer] The new limit.

On increasing the limit, some tasks may be immediately resumed. On decreasing the limit, some tasks may execute until the count is < than the limit.

Allow setting the limit. This is useful for cases where the semaphore is used to limit the number of concurrent tasks, but the number of tasks is not known in advance or needs to be modified.

def limit= limit
	difference = limit - @limit
	@limit = limit
	
	# We can't suspend 
	if difference > 0
		difference.times do
			break unless node = @waiting.first
			
			node.resume
		end
	end
end