without_ray_actor.py

'''
Count pixels without ray actor which will not work as expected
'''
import ray
import numpy as np
import time

ray.init()

total_pixels_processed = 0  # Our global counter.

@ray.remote
def process_image_and_count(image: np.ndarray) -> np.ndarray:
    # global keyword makes sure we refer to the global variable
    # but in Ray tasks, this creates a separate copy for each task.
    global total_pixels_processed
    # This update is only visible inside this specific task.
    total_pixels_processed += image.size
    print(f"Task processing {image.size} pixels. Local total: {total_pixels_processed}")
    time.sleep(1)
    return 255 - image

# Input: A list of 4 small, random images.
images = [np.random.randint(0, 255, (10, 10, 3)) for _ in range(4)]
image_size = images[0].size  # 300 pixels per image

# Launch the tasks.
ray.get([process_image_and_count.remote(img) for img in images])
print(f"Expected total pixels: {image_size * 4}")
print(f"Actual total pixels in main script: {total_pixels_processed}")