How can I avoid busy_wait from the event consumer thread using asyncio? I have a main thread which generates events which are processed by other thread. My event thread has busy_wait as it is trying to see if event queue has some item in it...
from Queue import Queue
from threading import Thread
import threading
def do_work(p):
print("print p - %s %s" % (p, threading.current_thread()))
def worker():
print("starting %s" % threading.current_thread())
while True: # <------------ busy wait
item = q.get()
do_work(item)
time.sleep(1)
q.task_done()
q = Queue()
t = Thread(target=worker)
t.daemon = True
t.start()
for item in range(20):
q.put(item)
q.join() # block until all tasks are done
How can I achieve something similar to the above code using asyncio?
asyncio makes sense only if you are working with IO, for example running an HTTP server or client. In the following example asyncio.sleep() simulates I/O calls. If you have a bunch of I/O tasks it can get as simple as:
import asyncio
import random
async def do_work(i):
print("[#{}] work part 1".format(i))
await asyncio.sleep(random.uniform(0.5, 2))
print("[#{}] work part 2".format(i))
await asyncio.sleep(random.uniform(0.1, 1))
print("[#{}] work part 3".format(i))
return "#{}".format(i)
loop = asyncio.get_event_loop()
tasks = [do_work(item + 1) for item in range(20)]
print("Start...")
results = loop.run_until_complete(asyncio.gather(*tasks))
print("...Done!")
print(results)
loop.close()
see also ensure_future and asyncio.Queue.