rust project-5: SharedQueueThreadPool doesn't exit when pool destroyed

[YangchenYe323]

Bug Report

1. What did you do?

Inspecting the source code in SharedQueueThreadPool

2. What did you expect to see?

The loop of function fn run_task(rx: TaskReceiver) should break when rx.0.recv returns an error and return from the function.

3. What did you see instead?

It logs an error message and goes on looping