C++ Boost::ASIO 线程池问题

Question

我刚刚为游戏服务器创建了我的线程池，但我在编译时遇到了一个我不知道如何修复的错误。

错误:

Connection/CConnection.cpp: In lambda function: Connection/CConnection.cpp:62:6: error: 'this' was not captured for this lambda function

线程池声明:

class Worker {
public:
    Worker(ThreadPool &s) : pool(s) { }
    void operator()();
private:
    ThreadPool &pool; 
};

// the actual thread pool
class ThreadPool {
public:
    ThreadPool(size_t);
    template<class F>
    void enqueue(F f);
    ~ThreadPool();
private:
    // need to keep track of threads so we can join them
    std::vector< std::unique_ptr<boost::thread> > workers;

    // the io_service we are wrapping
    boost::asio::io_service service;
    boost::asio::io_service::work working;
    friend class Worker;
};

template<class F>
void ThreadPool::enqueue(F f)
{
    service.post(f);
}

作用是什么:

void CConnection::handle()
{
     int i = 0;
     ThreadPool pool(4);
     pool.enqueue([i]
    {
     char * databuffer;
     databuffer = new char[16];
     for(int i = 0;i<16;i++)
     {
      databuffer[i] = 0x00;
     }
     databuffer[0] = 16;
     databuffer[4] = 1;
     databuffer[8] = 1;
     databuffer[12] = 1;
     asynchronousSend(databuffer, 16);
    });
}

有人能告诉我哪里有问题吗？

Answer 1

我的猜测是 asynchronousSend 是 CConnection 类中的一个函数。要在对象中调用函数，您必须捕获 this:

pool.enqueue([this] { ... });

如您所见，我已经删除了 i 的捕获，因为它不是必需的，因为您在 lambda 中声明了本地 i。