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async.h

thread_pool.h

enum class async_msg_type

/**
 * @brief 异步消息的类型，可以看出，spdlog将所有的控制都以message的方式来实现的
 *
 */
enum class async_msg_type
{
    log, flush, terminate
};

struct async_msg

/**
 * @brief Async msg to move to/from the queue. Movable only. should never be copied
 * 其对movable only的实现是值得借鉴的
 * 
 */
struct async_msg : log_msg_buffer
{
    // should only be moved in or out of the queue..
    async_msg(const async_msg &) = delete;  
    /**
     * @brief 第一个入参是rvalue 
     * 
     * @param worker
     * @param the_type
     * @param m
     */
    async_msg(async_logger_ptr &&worker, async_msg_type the_type, const details::log_msg &m)
};

class thread_pool

/**
 * @brief 线程池
 *
 */
class thread_pool
{
public:
    using item_type = async_msg;
    /**
     * 消息队列的类型
     */
    using q_type = details::mpmc_blocking_queue<item_type>;
    /**
     * @brief 添加一个log message到message queue中
     *
     * @param worker_ptr
     * @param msg
     * @param overflow_policy
     */
    void post_log(async_logger_ptr &&worker_ptr, const details::log_msg &msg, async_overflow_policy overflow_policy);
    /**
     * @brief 添加一个flush message到message queue中
     *
     * @param worker_ptr
     * @param overflow_policy
     */
    void post_flush(async_logger_ptr &&worker_ptr, async_overflow_policy overflow_policy);
private:
    /**
     * 消息队列
     */
    q_type q_;
    /**
     * 所有的thread
     */
    std::vector<std::thread> threads_;
    /**
     * @brief 线程执行函数
     *
     */
    void worker_loop_();
};

mpmc_blocking_q.h

class mpmc_blocking_queue

#include <condition_variable>
#include <mutex>

template<typename T>
class mpmc_blocking_queue
{
public:
    /**
     * @brief try to enqueue and block if no room left
     *
     * @param item
     */
    void enqueue(T &&item);
    /**
     * @brief enqueue immediately. overrun oldest message in the queue if no room left.
     *
     * @param item
     */
    void enqueue_nowait(T &&item);
    /**
     * @brief try to dequeue item. if no item found. wait upto timeout and try again
     * Return true, if succeeded dequeue item, false otherwise
     *
     * @param popped_item
     * @param wait_duration
     * @return
     */
    bool dequeue_for(T &popped_item, std::chrono::milliseconds wait_duration);
private:
    std::mutex queue_mutex_;
    std::condition_variable push_cv_;
    std::condition_variable pop_cv_;
    spdlog::details::circular_q<T> q_;
};

circular_q.h

在工程discrete的Structure\Data-structure\Array\Circular-array\spdlog-circular_q章节收录了中