Re: [Boost-users] Extended Thread object

From: Phil Endecott (spam_from_boost_users_at_[hidden])
Date: 2005-10-26 12:37:13

>>The actual application is a sort of daemon; a main loop accepts tcp
>>connections, and creates a new thread to handle each one.  It normally
>>wants to "fire and forget" these threads, and I imagine it creating them
>>with new() and then letting them dangle, until they eventually terminate
>>and delete themselves.
> 
> 
> I may be missing something here, but if thread lifetime and object
> lifetime are not tied, why not create the object on the stack (as part
> of an accept() loop, using the tcp connection example).  The stack
> based object will be destroied each loop, but the thread itself will
> continue to exist until it ends.

Yes, that's true.  I suppose I'm thinking this way because I'm also 
imagining that I can subclass this new Thread class to add state, e.g.

class DaemonThread: public Thread {
private:
   ... per-connection state ...

public:
   DaemonThread(int connection_fd);
};

void mainloop() {
   while(1) {
     int fd = accept_connection_on_socket();
     DaemonThread* handler = new DaemonThread(fd);
   }
}

If instead I put the state in another object that's created within the 
thread's initial function then I can afford for the actual thread object 
to expire immediately.  There must be lots of ways to do this sort of thing.

> You could also use boost::call_once to "fire and forget"

I think I know what call_once() does but I don't see how it helps.  Can 
you elaborate?

Cheers,

--Phil.