用boost_bind封装线程函数

Question

我目前正在创建这样的 boost::threads ：

  boost::thread m_myThread; //member variable
  //...
  m_myThread = boost::thread(boost::bind(&MyClass::myThreadFunction, this));

这将启动一个执行成员函数“myThreadFunction”的线程。

我想封装一个新线程的启动，并使用类似

boost::thread m_myThread; //member variable
//...
startAThread(&m_myThread, boost::bind(&MyClass::myThreadFunction, this), 123 /*some int argument*/);

我认为可以实现“startAThread”的东西：

namespace internal
{
    template <typename Callable>
    void threadhelper(Callable func, int x)
    {
        doSomething(x);
        func();
    }
}
template <typename Callable>
void startAThread(boost::thread* threadToCreate, Callable func, int x)
{

    *threadToCreate = boost::thread(boost::bind(internal::threadhelper<Callable>, func, x));
}

但是，这无法编译，

usr/include/boost/bind/bind.hpp: In member function 'void boost::_bi::list2<A1, A2>::operator()(boost::_bi::type<void>, F&, A&, int) [with F = void (*)(boost::_bi::bind_t<void, boost::_mfi::mf0<void, MyClass>, boost::_bi::list1<boost::_bi::value<MyClass*> > >, int), A = boost::_bi::list0, A1 = boost::_bi::bind_t<void, boost::_mfi::mf0<void, MyClass>, boost::_bi::list1<boost::_bi::value<MyClass*> > >, A2 = boost::_bi::value<int>]':
usr/include/boost/bind/bind_template.hpp:20:   instantiated from 'typename boost::_bi::result_traits<R, F>::type boost::_bi::bind_t<R, F, L>::operator()() [with R = void, F = void (*)(boost::_bi::bind_t<void, boost::_mfi::mf0<void, MyClass>, boost::_bi::list1<boost::_bi::value<MyClass*> > >, int), L = boost::_bi::list2<boost::_bi::bind_t<void, boost::_mfi::mf0<void, MyClass>, boost::_bi::list1<boost::_bi::value<MyClass*> > >, boost::_bi::value<int> >]'
usr/include/boost/thread/detail/thread.hpp:61:   instantiated from 'void boost::detail::thread_data<F>::run() [with F = boost::_bi::bind_t<void, void (*)(boost::_bi::bind_t<void, boost::_mfi::mf0<void, MyClass>, boost::_bi::list1<boost::_bi::value<MyClass*> > >, int), boost::_bi::list2<boost::_bi::bind_t<void, boost::_mfi::mf0<void, MyClass>, boost::_bi::list1<boost::_bi::value<MyClass*> > >, boost::_bi::value<int> > >]'
MyClass.cpp:160:   instantiated from here
usr/include/boost/bind/bind.hpp:313: error: conversion from 'void' to non-scalar type 'boost::_bi::bind_t<void, boost::_mfi::mf0<void, MyClass>, boost::_bi::list1<boost::_bi::value<MyClass*> > >' requested

这个错误是什么意思？代码有什么问题吗？

多谢！

Answer 1

尝试

namespace internal
{
    template <typename Callable>
    void threadhelper(Callable func, int x)
    {
        doSomething(x);
        func();
    }
}
template <typename Callable>
void startAThread(boost::thread& threadToCreate, Callable func, int x) {        
    threadToCreate = boost::thread(boost::bind(&internal::threadhelper<Callable>, func, x));
}

我也使用引用而不是指针。