Python-100-Days/Day16-20/code/example21.py

67 lines
1.7 KiB
Python
Raw Blame History

This file contains ambiguous Unicode characters!

This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.

"""
多个线程竞争一个资源 - 保护临界资源 - 锁Lock/RLock
多个线程竞争多个资源(线程数>资源数) - 信号量Semaphore
多个线程的调度 - 暂停线程执行/唤醒等待中的线程 - Condition
"""
from concurrent.futures import ThreadPoolExecutor
from random import randint
from time import sleep
import threading
class Account():
"""银行账户"""
def __init__(self, balance=0):
self.balance = balance
lock = threading.Lock()
self.condition = threading.Condition(lock)
def withdraw(self, money):
"""取钱"""
with self.condition:
while money > self.balance:
self.condition.wait()
new_balance = self.balance - money
sleep(0.001)
self.balance = new_balance
def deposit(self, money):
"""存钱"""
with self.condition:
new_balance = self.balance + money
sleep(0.001)
self.balance = new_balance
self.condition.notify_all()
def add_money(account):
while True:
money = randint(5, 10)
account.deposit(money)
print(threading.current_thread().name,
':', money, '====>', account.balance)
sleep(0.5)
def sub_money(account):
while True:
money = randint(10, 30)
account.withdraw(money)
print(threading.current_thread().name,
':', money, '<====', account.balance)
sleep(1)
def main():
account = Account()
with ThreadPoolExecutor(max_workers=10) as pool:
for _ in range(5):
pool.submit(add_money, account)
pool.submit(sub_money, account)
if __name__ == '__main__':
main()