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GitHub Repository: jackfrued/Python-100-Days
 Path: blob/master/Day16-20/code/example21.py
Views: 729
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"""

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多个线程竞争一个资源 - 保护临界资源 - 锁（Lock/RLock）

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多个线程竞争多个资源（线程数>资源数） - 信号量（Semaphore）

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多个线程的调度 - 暂停线程执行/唤醒等待中的线程 - Condition

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"""

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from concurrent.futures import ThreadPoolExecutor

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from random import randint

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from time import sleep

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import threading

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class Account():

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    """银行账户"""

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    def __init__(self, balance=0):

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        self.balance = balance

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        lock = threading.Lock()

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        self.condition = threading.Condition(lock)

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    def withdraw(self, money):

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        """取钱"""

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        with self.condition:

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            while money > self.balance:

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                self.condition.wait()

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            new_balance = self.balance - money

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            sleep(0.001)

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            self.balance = new_balance

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    def deposit(self, money):

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        """存钱"""

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        with self.condition:

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            new_balance = self.balance + money

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            sleep(0.001)

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            self.balance = new_balance

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            self.condition.notify_all()

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def add_money(account):

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    while True:

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        money = randint(5, 10)

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        account.deposit(money)

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        print(threading.current_thread().name,

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              ':', money, '====>', account.balance)

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        sleep(0.5)

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def sub_money(account):

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    while True:

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        money = randint(10, 30)

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        account.withdraw(money)

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        print(threading.current_thread().name,

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              ':', money, '<====', account.balance)

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        sleep(1)

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def main():

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    account = Account()

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    with ThreadPoolExecutor(max_workers=10) as pool:

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        for _ in range(5):

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            pool.submit(add_money, account)

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            pool.submit(sub_money, account)

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if __name__ == '__main__':

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    main()

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