Re: [Boost-users] [asio] asynchronous reading/writing to the tcp stream

On 7/11/2012 12:42 PM, Ovanes Markarian wrote:

On Wed, Jul 11, 2012 at 6:27 PM, Nat Linden wrote:

...

On Wed, Jul 11, 2012 at 12:05 PM, Ovanes Markarian wrote:

...

On Wed, Jul 11, 2012 at 5:10 PM, Nat Linden wrote:

...

...

When you want code that appears to block, but is actually driven by asynchronous I/O, that's a use case for Boost.Coroutine. Interestingly, the new Coroutine is supposed to be reviewed very soon: http://olk.bplaced.net/boost-coroutine.zip

...

Nat thanks for the quick reply... But what happens with the tcp::iostream if another thread starts to read from it after a connection was open, but no response is there? Would not it block? Is it even safe to write requests to the tcp::iostream from one thread and read it from the other? As I stated before, I would like to solve the issue with ASIO only. I might be able to review coroutine lib, but I don't think this an option for us in this project.

coroutine != thread. :-)

A coroutine is user-space context switching, and it happens at well-defined times. It's just a way of organizing code that must otherwise be structured to receive intermittent calls -- as with an ASIO completion handler.

Nat,

I know what coroutines, fibers or user space threads are... But using them I still need to do some additional impl, which I don't want. I first want to know if I can read/write to tcp::iostream from two different threads and if yes, than how should I do it best.

Thanks, Ovanes _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

In my experience, no. tcp::iostream is not thread-safe. What I did was use boost::iostreams to create a separate istream and ostream which wrapped the same raw socket descriptor (since boost::iostreams is not thread-safe either). Andy