Re: [Boost-users] functor for boost::thread_group threads: which one is correct?

Subject: Re: [Boost-users] functor for boost::thread_group threads: which one is correct?
From: Mathias Gaunard (mathias.gaunard_at_[hidden])
Date: 2009-08-23 22:05:37

Boost lzw wrote:

> class group_helper           
> {                           
> private:
>     boost::shared_ptr<FileThread> m_object;   
> public:                       
>     group_helper() : m_object(boost::shared_ptr<FileThread>(new 
> FileThread))
>              { std::cout << "group_helper::ctor called" << std::endl;}
>     void operator()() { m_object->find(); m_object->print(); }
>     ~group_helper() { std::cout << "group_helper::***dtor called" << 
> std::endl; }
> };
> 
> int main()
> {
>     group_helper gp;
>     boost::thread_group threads;
>         for (int i = 0; i < 1; ++i)
>             threads.create_thread(gp);       
>         threads.join_all();                   
> 
>     return 0;
> }
> ===========
> Output: 1 call to "group_helper::ctor called"
>     6 calls to "group_helper::***dtor called"
> ===========
> If the code is correct, does this mean that with thread_group we can no 
> longer expect the # of ctors matches that of the dtors in threaded code?

It has nothing to do with threads, it's because you're not displaying 
calls to the copy constructor.