How can I perform calculations in the background¶
You can use this code in the task server module to run a background thread in the web application once a 3 minutes (can be changed by setting interval) to perform some calculations:
import threading import time import traceback def background(task): interval = 3 * 60 time.sleep(interval) while True: if not time: return with task.lock('background'): try: print('background') # some code to execute in background for example: # tracks = task.tracks.copy() # tracks.open() # for t in tracks: # t.edit() # t.sold.value = #some value # t.post() # tracks.apply() except Exception as e: traceback.print_exc() time.sleep(interval) def on_created(task): bg = threading.Thread(target=background, args=(task,)) bg.daemon = True bg.start()
When multiple web applications are running in parallel processes, the background function will be executed in each process. To prevent simultaneous execution of this function, we use the lock method of the task.