Godot background load

extends Node

signal scene_loaded

var file
var thread
var mutex
var semaphore
var resource
var exit_thread = false
var props = {} #Extra info passed along loading request

func _ready():
    file = File.new()
    thread = Thread.new()
    mutex = Mutex.new()
    semaphore = Semaphore.new()
    thread.start(self, "thread_func")

func load_scene(path, instruction):
    mutex.lock()
    if !file_check(path):
        print("File does not exist: " + path)
        return
    mutex.unlock()

    mutex.lock()
    props[path] = instruction
    resource = path
    mutex.unlock()

    semaphore.post()

func file_check(path)->bool:
    var result = false
    mutex.lock()
    result = file.file_exists(path)
    mutex.unlock()
    return result

func thread_func(null):
    while true: #Trap the function
        semaphore.wait()    #start the work when semaphote.post()

        mutex.lock()
        var should_exit = exit_thread # Protect with Mutex.
        mutex.unlock()

        if should_exit:
            break

        mutex.lock() #didn't feel like to do separate lock
        var scene = load(resource)
        call_deferred("emit_signal", "scene_loaded", {resource=scene, instructions = props[resource]})
        mutex.unlock()

func _exit_tree(): #even autoloaded script needs to do this or bricks on quiting
    mutex.lock()
    exit_thread = true #this is checked in thread
    mutex.unlock()

    semaphore.post()    #give last resume to the function to see it neads to break
    thread.wait_to_finish() #sync the threads