lesson05_lock.py

# SuperFastPython.com
# example of an asyncio mutual exclusion (mutex) lock
from random import random
import asyncio

# task coroutine with a critical section
async def task(lock, num, value):
 # acquire the lock to protect the critical section
 async with lock:
 # report a message
 print(f'>{num} got the lock, sleep for {value}')
 # suspend for a moment
 await asyncio.sleep(value)

# entry point
async def main():
 # create a shared lock
 lock = asyncio.Lock()
 # create many concurrent coroutines
 coros = [task(lock, i, random()) for i in range(10)]
 # execute and wait for tasks to complete
 await asyncio.gather(*coros)

# run the asyncio program
asyncio.run(main())