C++如何实现一个阻塞队列_C++11使用条件变量和互斥锁实现线程安全队列

#include 
#include 
#include 
#include 

template 
class BlockingQueue {
private:
    std::queue data_queue_;
    std::mutex mtx_;
    std::condition_variable not_full_;
    std::condition_variable not_empty_;
    size_t capacity_;

public:
    explicit BlockingQueue(size_t cap = 1000) : capacity_(cap) {}

    void put(const T& item) {
        std::unique_lock lock(mtx_);
        // 等待队列不满
        not_full_.wait(lock, [this] { return data_queue_.size() < capacity_; });
        data_queue_.push(item);
        not_empty_.notify_one(); // 通知消费者
    }

    void take(T& item) {
        std::unique_lock lock(mtx_);
        // 等待队列不空
        not_empty_.wait(lock, [this] { return !data_queue_.empty(); });
        item = data_queue_.front();
        data_queue_.pop();
        not_full_.notify_one(); // 通知生产者
    }

    bool empty() const {
        std::lock_guard lock(mtx_);
        return data_queue_.empty();
    }

    size_t size() const {
        std::lock_guard lock(mtx_);
        return data_queue_.size();
    }
};

#include 
#include 

int main() {
    BlockingQueue queue(5);

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

    auto consumer = [&]() {
        int value;
        for (int i = 0; i < 10; ++i) {
            queue.take(value);
            std::cout << "Consumed: " << value << "\n";
        }
    };

    std::thread t1(producer);
    std::thread t2(consumer);

    t1.join();
    t2.join();

    return 0;
}