lesson04_mutex_lock.py

# SuperFastPython.com
# example of protecting a critical section with a mutex
from time import sleep
from random import random
from threading import Thread
from threading import Lock

# custom function to be executed in a new thread
def task(shared_lock, ident, value):
 # acquire the lock
 with shared_lock:
 # report a message
 print(f'>{ident} got lock, sleeping {value}')
 # block for a fraction of a second
 sleep(value)

# protect the entry point
if __name__ == '__main__':
 # create the shared mutex lock
 lock = Lock()
 # create a number of threads with different args
 threads = [Thread(target=task,
 args=(lock, i, random())) for i in range(10)]
 # start the threads
 for thread in threads:
 thread.start()
 # wait for all threads to finish
 for thread in threads:
 thread.join()