Question

所以这是我第一次在C ++中完成任何多线程。现在我的代码抛出了一些我无法识别的错误，但它似乎表明当我包含boost / thread.hpp时会发生这种错误。

错误看起来像这样。

  In file included 

             from /usr/include/boost/mem_fn.hpp:22:0,
             from /usr/include/boost/bind/bind.hpp:26,
             from /usr/include/boost/bind.hpp:22,
             from /usr/include/boost/thread/detail/thread.hpp:22,
             from /usr/include/boost/thread/thread.hpp:22,
             from /usr/include/boost/thread.hpp:13,
             from processes/Video_process.h:8,
             from processes/Video_process.cpp:7:

             /usr/include/boost/bind/mem_fn.hpp: In member function ‘R& boost::_mfi::dm<R, T>::operator()(T*) const [with R = void*(void*), T = Video_process]’:
             /usr/include/boost/bind/bind.hpp:243:60:   instantiated from ‘R boost::_bi::list1<A1>::operator()(boost::_bi::type<R>, F&, A&, long int) [with R = void* (&)(void*), F = boost::_mfi::dm<void*(void*), Video_process>, A = boost::_bi::list0, A1 = boost::_bi::value<Video_process*>]’

             /usr/include/boost/bind/bind_template.hpp:20:59:   instantiated from ‘boost::_bi::bind_t<R, F, L>::result_type boost::_bi::bind_t<R, F, L>::operator()() [with R = void* (&)(void*), F = boost::_mfi::dm<void*(void*), Video_process>, L = boost::_bi::list1<boost::_bi::value<Video_process*> >, boost::_bi::bind_t<R, F, L>::result_type = void* (&)(void*)]’
             /usr/include/boost/thread/detail/thread.hpp:61:17:   instantiated from ‘void boost::detail::thread_data<F>::run() [with F = boost::_bi::bind_t<void* (&)(void*), boost::_mfi::dm<void*(void*), Video_process>, boost::_bi::list1<boost::_bi::value<Video_process*> > >]’
             processes/Video_process.cpp:240:1:   instantiated from here
             /usr/include/boost/bind/mem_fn.hpp:342:23: error: invalid use of non-static member function

我的代码有点长，所以我不知道哪些位有用但是这里有一些反正......

1

  boost::unique_lock<boost::mutex> lock(mx); 
  lock.lock();
    (...) //stuff
  is_data_ready = 1;
  lock.unlock();

2

stserver = boost::shared_ptr<boost::thread>
 (new boost::thread(boost::bind(&Video_process::streamServer, this)));

以下是如何在标题

中声明streamServer

void* streamServer(void* arg);

Answer 1

boost::bind中显示的错误基本上表示您的成员函数void* Video_process::streamServer(void* arg)需要两个参数this和void*。您的代码仅绑定第一个参数。

如果你想将它与boost::thread一起使用，它不应该要求第二个void*参数或将它绑定到一个常量。此外，boost::thread会丢弃仿函数的返回值，因此您可能希望使用void，即：

struct Video_process {
    void streamServer();
};

boost::thread(boost::bind(&Video_process::streamServer, this));
// or simply
boost::thread(&Video_process::streamServer, this);

关于：

boost::unique_lock<boost::mutex> lock(mx); 
lock.lock();

第一行在构造函数中锁定互斥锁，因此第二行显式锁定是不必要的。

包含boost库时出错

1 个答案: