On Mon, 07 Apr 2008 11:40:48 +0200, Sebastian Redl <sebastian.redl@getdesigned.at> wrote:
Boris wrote:
I ask as I was trying to extend Boost.Asio and add support for C++ standard streams on the weekend. I came to the conclusion that C++ this is impossible (as calls to C++ standard streams block and there is no way to interrupt a blocking call, at least not in a portable way).
The only way to simulate asynchronous I/O using blocking calls is to use a separate thread for every I/O object.
This doesn't work either as you can't interrupt the blocking call if you want to close the stream.
Two ways: 1.) use asynchronous I/O with aio-system calls (UNIX: aio_read/aio_write, ... whith aiocb struct; AFAIK not supported by boost::asio) Note: AIO is not supported on all systems (for instance on LINUX aio doesn't realy support sockets) and other I/O techniques maybe faster and more efficient. 2.) use synchronous I/O with non-blocking descriptors, demultiplexing techniques (select, epoll, kqueue,...) and threads (==the way boost::asio works). regards, Oliver