car-os/networking/scripts/udp_broadcast.gd

# client_node.gd
class_name ClientNode
extends Node

var udp = PacketPeerUDP.new()
var connected = false

var fast_broadcast_rate = 0.5
var slow_broadcast_rate = 10.0
var current_broadcast_rate = fast_broadcast_rate
var last_broadcast = 0

var ip_address: String = ""

var thread: Thread
var mutex: Mutex
var signal_queue = []
var exit_thread = false
var use_thread = true

func _ready():
	_try_set_ip()
	udp.set_broadcast_enabled(true)
	udp.set_dest_address("192.168.0.255", 5000)
	SensorSignals.new_sensor_connected.connect(_on_sensor_connected)
	
	use_thread = OS.get_processor_count() > 1
	mutex = Mutex.new()
	if use_thread:
		thread = Thread.new()
		print('Starting UDP Broadcast thread')
		thread.start(_thread_function)
	else:
		print('UDP server running in single threaded mode')

func _process(delta: float) -> void:
	mutex.lock()
	last_broadcast += delta
	mutex.unlock()
	if not use_thread:
		_process_broadcast()

func _exit_tree() -> void:
	if use_thread:
		mutex.lock()
		exit_thread = true
		mutex.unlock()
		thread.wait_to_finish()

func _thread_function():
	print('UDP Broadcast thread started')
	while true:
		mutex.lock()
		var should_exit = exit_thread
		mutex.unlock()
		if should_exit:
			break
		mutex.lock()
		var do_broadcast = last_broadcast >= current_broadcast_rate
		mutex.unlock()
		if do_broadcast:
			mutex.lock()
			last_broadcast = 0
			mutex.unlock()
			_process_broadcast()

func _process_broadcast():
	if ip_address.length() == 0:
		_try_set_ip()
		return
		# Try to contact server
	var broadcast_str = ip_address + "|%s" % Time.get_datetime_string_from_system(true)
	print('Broadcasting to UDP: ', broadcast_str)
	udp.put_packet(broadcast_str.to_utf8_buffer())

func _try_set_ip():
	for address in IP.get_local_addresses():
		if address.begins_with("192"):
			if address.ends_with("0.1"):
				continue
			ip_address = address
			break
	
func _on_sensor_connected(sensor_ip, sensor_data):
	current_broadcast_rate = slow_broadcast_rate