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GPT

WhiteBox

Implement a Thread Safe Queue

WhiteBox

namespace blackbox
{
template <typename T>
class ThreadSafeQueue
{
public:
    void push(T value)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        queue_.push(std::move(value));
        cond_.notify_one();
    }
    bool try_pop(T& out)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (queue_.empty()) return false;
        out = std::move(queue_.front());
        queue_.pop();
        return true;
    }
    T wait_and_pop()
    {
        std::unique_lock<std::mutex> lock(mutex_);
        cond_.wait(lock, [this] { return !queue_.empty(); });
        T value = std::move(queue_.front());
        queue_.pop();
        return value;
    }
    bool empty() const
    {
        std::lock_guard<std::mutex> lock(mutex_);
        return queue_.empty();
    }
private:
    std::queue<T> queue_;
    mutable std::mutex mutex_;
    std::condition_variable cond_;
};
}

namespace whitebox
{
template <typename T>
class ThreadSafeQueue
{
public:
    void push(T value)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        queue_.push(std::move(value));
        cond_.notify_one();
    }
    bool try_pop(T& out)
    {
        std::lock_guard<std::mutex> lock(mutex_);
        if (queue_.empty()) return false;
        out = std::move(queue_.front());
        queue_.pop();
        return true;
    }
    T wait_and_pop()
    {
        std::unique_lock<std::mutex> lock(mutex_);
        cond_.wait(lock, [this] { return !queue_.empty(); });
        T value = std::move(queue_.front());
        queue_.pop();
        return value;
    }
    bool empty() const
    {
        std::lock_guard<std::mutex> lock(mutex_);
        return queue_.empty();
    }
private:
    std::queue<T> queue_;
    mutable std::mutex mutex_;
    std::condition_variable cond_;
};
}