Re: [boost] Re: Boost.Threads - thread_desc concept

From: Peter Dimov (pdimov_at_[hidden])
Date: 2001-07-02 13:28:32

From: <williamkempf_at_[hidden]>

> > class thread_group
> > {
> > public:
> >     // all implicit members are fine and useful
> >
> >     template<class F> void create(F f)
> >     {
> >         v_.push_back(new thread(f));
> >     }
> >
> >     void join_all()
> >     {
> >         std::vector<thread*>::iterator it = v_.begin();
> >         while (it != v_.end())
> >         {
> >            (*it)->join();
>
> Ooops... that's what I get for doing this on the fly.  You need the
> following line as well:
>
>              delete *it;
> >            it = v_.erase(it);
> >         }
> >     }
> >
> > private:
> >     std::vector<thread*> v_;
> > };
>
> I should also note that this is a poor implementation of a
> thread_group, the destruction and removal from the group should
> probably only be done in the object's destructor and no during the
> call to join_all().

Yep. And some of the implicit members are neither fine nor useful. :-)

This is not meant to pick on your ability to write bug-free code on the fly
in an e-mail. Nobody can do that.

But if you consider "Bill Kempf/Peter Dimov writing code on the fly in an
e-mail" as a rough measure of what the "average" C++ programmer is likely to
come up with, you'll see that this "unofficial thread_group test" does
provide some indications as to which design is less error prone and easier
to use.

--
Peter Dimov
Multi Media Ltd.