c++怎么实现一个线程安全的队列_c++中线程安全队列的实现思路与代码示例

#include <queue>
#include <mutex>
#include <condition_variable>
#include <thread>
#include <iostream>

template<typename T>
class ThreadSafeQueue {
private:
    std::queue<T> data_queue;
    mutable std::mutex mtx;
    std::condition_variable cv;

public:
    ThreadSafeQueue() = default;

    void push(T value) {
        std::lock_guard<std::mutex> lock(mtx);
        data_queue.push(std::move(value));
        cv.notify_one(); // 唤醒一个等待的消费者
    }

    bool try_pop(T& value) {
        std::lock_guard<std::mutex> lock(mtx);
        if (data_queue.empty()) {
            return false;
        }
        value = std::move(data_queue.front());
        data_queue.pop();
        return true;
    }

    void wait_and_pop(T& value) {
        std::unique_lock<std::mutex> lock(mtx);
        cv.wait(lock, [this] { return !data_queue.empty(); });
        value = std::move(data_queue.front());
        data_queue.pop();
    }

    bool empty() const {
        std::lock_guard<std::mutex> lock(mtx);
        return data_queue.empty();
    }

    size_t size() const {
        std::lock_guard<std::mutex> lock(mtx);
        return data_queue.size();
    }
};

int main() {
    ThreadSafeQueue<int> queue;

    auto producer = [&]() {
        for (int i = 0; i < 10; ++i) {
            queue.push(i);
            std::cout << "Produced: " << i << "\n";
            std::this_thread::sleep_for(std::chrono::milliseconds(100));
        }
    };

    auto consumer = [&](int id) {
        for (int i = 0; i < 5; ++i) {
            int value;
            queue.wait_and_pop(value);
            std::cout << "Consumer " << id << " got: " << value << "\n";
        }
    };

    std::thread p(producer);
    std::thread c1(consumer, 1);
    std::thread c2(consumer, 2);

    p.join();
    c1.join();
    c2.join();

    return 0;
}