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Few python scrtips to show how to use asychio.
author MrJuneJune <me@mrjunejune.com>
date Sat, 13 Dec 2025 14:23:02 -0800
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47:829623189a57 48:46daba6e3cf4
1 # Bank Account
2
3 You are given a simplified multi-threaded “bank account” implementation used by one of our infrastructure teams. The current code processes deposits concurrently but produces incorrect results.
4
5 ```
6 class BankAccount:
7 def __init__(self, balance):
8 self.balance = balance
9
10 def deposit(self, amount):
11 new_balance = self.balance + amount # read
12 time.sleep(0.1) # simulate delay
13 self.balance = new_balance # write
14
15 account = BankAccount(0)
16
17 with ThreadPoolExecutor(max_workers=2) as executor:
18 futures = [
19 executor.submit(account.deposit, 500),
20 executor.submit(account.deposit, 700),
21 ]
22 ```
23
24 Task
25
26 Identify the concurrency bugs in the implementation.
27
28 Explain why these bugs occur.
29
30 Fix the implementation without modifying the existing BankAccount class directly.
31
32 You may use subclassing (Python) or embedding (Go-style composition), depending on the language you choose.
33
34 Ensure your solution is thread-safe and produces the correct final balance (1200).