Code reviewHardcr-g543

Subject Code reviewLevel Senior–Staff~20 minCommon in Concurrency interviewsIndustries Software development

Question

Review this Rust inventory decrementer shared across worker threads via Arc<Mutex<...>>.

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Code to reviewrust

1fn reserve(stock: &Arc<Mutex<HashMap<u64, i32>>>, sku: u64, n: i32) -> bool {2    let available = {3        let map = stock.lock().unwrap();4        *map.get(&sku).unwrap_or(&0)5    };6    if available < n {7        return false;8    }9    let mut map = stock.lock().unwrap();10    *map.entry(sku).or_insert(0) -= n;11    true12}

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