Re: [boost] [asio] SSL operation sporadically returns "Access is denied"

From: Christopher Kohlhoff (chris_at_[hidden])
Date: 2006-09-29 18:06:45

Hi Scott,

Scott <cheesy4poofs_at_[hidden]> wrote:
> I grabbed the code in boost CVS about 2 weeks ago.  Should I
> get latest again?

No, that will do.

> the client, that's probably acceptable.  But for the server we
> really need multiple threads.  Is it okay for each thread to
> create it's own io_service to solve this problem?

Yep, that's a perfectly good server design. You simply use some
"load balancing" technique like round-robin to allocate incoming
connections to io_service objects. (Yes, it is ok to have the
acceptor and the socket being accepted on different io_service
objects.)

Depending on what else the server does, another approach might
be to use a single io_service and single thread to do all I/O
related work, and use another thread pool (possibly using
another io_service) to perform the work that really needs
multiple threads.

> So, if I understand correctly, the UI should *not* be using
> the socket class because we spawn a background thread to
> receive data on that socket?

Yep. Basically the approach Martin suggested is the one to use.
So, in the client:

- Spawn a background thread to call io_service::run()
- When data arrives on the socket post it the GUI using a
  windows message
- When you need to initiate an I/O operation, post a function
  object to the background thread by using io_service::post().

For the server, you can:

- Use one thread per io_service object to call io_service::run().
- Allocate connections to io_services e.g. using round robin
- When you want to initiate an unsolicited send on a particular
  connection, post a function object to that connection's
  io_service object.

or:

- Use on io_service object for all I/O, and another for managing
  a thread pool.
- Use io_service::post() to send function objects between the
  objects that are associated with each io_service.

Cheers,
Chris