cppAsync race conditionHard

Concurrent Counter Increment Causes Data Race on ARM

Time: 0:00

BugFind the bug and fix the code

What it should do

Increment a shared counter in a thread-safe manner. Example: incrementCounter() -> void

What happens instead

Data race detected on ARM architecture during concurrent execution.

#include <atomic>

std::atomic<int> counter(0);

void incrementCounter() {
   int current = counter.load();
   counter.store(current + 1);
}

void test() {
   for (int i = 0; i < 1000; ++i) {
      incrementCounter();
   }
}

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 async and race conditions pattern

A missing await, unbuffered channel deadlocks, ConcurrentModificationException, and data races under load.

Learn the async and race conditions pattern Step through your own code

<iframe src="https://trybughunt.com/embed/8b94e75d-2038-43c3-bc97-cb3fe961ded8" title="Debugging challenge: Concurrent Counter Increment Causes Data Race on ARM" 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/8b94e75d-2038-43c3-bc97-cb3fe961ded8">TryBugHunt</a></p>

#include <atomic> std::atomic<int> counter(0); void incrementCounter() { int current = counter.load(); counter.store(current + 1); } void test() { for (int i = 0; i < 1000; ++i) { incrementCounter(); } }

Concurrent Counter Increment Causes Data Race on ARM

What it should do

What happens instead

More async and race conditions to practise

Concurrent Counter Increment Causes Data Race on ARM

What it should do

What happens instead

More async and race conditions to practise