Code reviewHardcr-g422

Subject Race conditionsLevel Senior–Staff~28 minCommon in Concurrency interviewsIndustries Software development, Technology

Question

Review this C++ per-thread counter array used to aggregate stats across N worker threads. Each worker increments its own slot in a tight loop, then a reader sums them.

What a strong answer looks like

Separate real bugs from style. Rank issues by severity, point at the root cause rather than the symptom, and suggest a concrete fix — specific and kind.

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Code to reviewcpp

1struct Counters {2  std::atomic<long> hits[64];   // one slot per worker thread3};4 5void worker(Counters& c, int id) {6  for (int i = 0; i < 100000000; ++i)7    c.hits[id].fetch_add(1, std::memory_order_relaxed);8}

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