| [/ |
| / Copyright (c) 2003-2010 Christopher M. Kohlhoff (chris at kohlhoff dot com) |
| / |
| / Distributed under the Boost Software License, Version 1.0. (See accompanying |
| / file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| /] |
| |
| [section:reactor Reactor-Style Operations] |
| |
| Sometimes a program must be integrated with a third-party library that wants to |
| perform the I/O operations itself. To facilitate this, Boost.Asio includes a |
| `null_buffers` type that can be used with both read and write operations. A |
| `null_buffers` operation doesn't return until the I/O object is "ready" to |
| perform the operation. |
| |
| As an example, to perform a non-blocking read something like the |
| following may be used: |
| |
| ip::tcp::socket socket(my_io_service); |
| ... |
| ip::tcp::socket::non_blocking nb(true); |
| socket.io_control(nb); |
| ... |
| socket.async_read_some(null_buffers(), read_handler); |
| ... |
| void read_handler(boost::system::error_code ec) |
| { |
| if (!ec) |
| { |
| std::vector<char> buf(socket.available()); |
| socket.read_some(buffer(buf)); |
| } |
| } |
| |
| These operations are supported for sockets on all platforms, and for the POSIX |
| stream-oriented descriptor classes. |
| |
| [heading See Also] |
| |
| [link boost_asio.reference.null_buffers null_buffers], |
| [link boost_asio.examples.nonblocking nonblocking example]. |
| |
| [endsect] |