# Wrapper for the data structure used for polling on a socket
class PollFD
	super FinalizableOnce

	# The PollFD object
	private var poll_struct: NativeSocketPollFD

	# A collection of the events to be watched
	var events: Array[NativeSocketPollValues]

	# Create a PollFD object from NativePollFD informations
	init from_poll_values(pid: Int, events: Array[NativeSocketPollValues])
	do
		assert events.length >= 1

		var events_in_one = events[0]

		for i in [1 .. events.length - 1] do
			events_in_one += events[i]
		end

		var poll_struct = new NativeSocketPollFD(pid, events_in_one)

		init(poll_struct, events)
	end

	# Reads the response and returns an array with the type of events that have been found
	private fun check_response(response: Int): Array[NativeSocketPollValues]
	do
		var resp_array = new Array[NativeSocketPollValues]
		for i in events do
			if c_check_resp(response, i) != 0 then
				resp_array.push(i)
			end
		end
		return resp_array
	end

	# Checks if the poll call has returned true for a particular type of event
	private fun c_check_resp(response: Int, mask: NativeSocketPollValues): Int
	`{
		return response & mask;
	`}

	redef fun finalize_once
	do
		poll_struct.free
	end
end