rustLogic errorHard

Unbounded channel memory leak under fast producer

Time: 0:00

BugFind the bug and fix the code

What it should do

Send items with bounded capacity and drain all. Example: bounded_channel_transfer(3) -> 3

What happens instead

Channel fills unbounded memory without backpressure

use std::sync::mpsc;

fn bounded_channel_transfer(n: i32) -> i32 {
    // Unbounded mpsc::channel can consume unbounded memory
    let (tx, rx) = mpsc::channel();
    for i in 0..n {
        tx.send(i).unwrap();
    }
    let mut count = 0;
    while let Ok(_) = rx.try_recv() {
        count += 1;
    }
    count
}

fn main() {
    println!("{}", bounded_channel_transfer(3));
}

Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).

⏱️0:00

Hints

🏆 0 hints = Flawless Solve

Think & Test Cooldown

2:00 remaining

Take a moment to read the bug symptom and trace the code with Run & Check before unlocking Hint 1.

Hint 2

Unlocks after Hint 1

Hint 3

Unlocks after Hint 2

This bug belongs to the logic errors pattern

The wrong operator, an inverted condition, a formula the right way round but backwards.

Learn the logic errors pattern Step through your own code

<iframe src="https://trybughunt.com/embed/9846b593-66af-4e2b-bd0c-1044d98b3a42" title="Debugging challenge: Unbounded channel memory leak under fast producer" width="100%" height="580" loading="lazy" style="border:1px solid #d4d4d8;border-radius:12px;max-width:760px"></iframe> <p style="font-size:14px">Debugging challenge from <a href="https://trybughunt.com/challenges/9846b593-66af-4e2b-bd0c-1044d98b3a42">TryBugHunt</a></p>

use std::sync::mpsc; fn bounded_channel_transfer(n: i32) -> i32 { // Unbounded mpsc::channel can consume unbounded memory let (tx, rx) = mpsc::channel(); for i in 0..n { tx.send(i).unwrap(); } let mut count = 0; while let Ok(_) = rx.try_recv() { count += 1; } count } fn main() { println!("{}", bounded_channel_transfer(3)); }

Unbounded channel memory leak under fast producer

What it should do

What happens instead

More logic errors to practise

Unbounded channel memory leak under fast producer

What it should do

What happens instead

More logic errors to practise