diff options
Diffstat (limited to '3rdparty/asio/src/examples/cpp03/nonblocking/third_party_lib.cpp')
-rw-r--r-- | 3rdparty/asio/src/examples/cpp03/nonblocking/third_party_lib.cpp | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/3rdparty/asio/src/examples/cpp03/nonblocking/third_party_lib.cpp b/3rdparty/asio/src/examples/cpp03/nonblocking/third_party_lib.cpp new file mode 100644 index 00000000000..8ec06f6034d --- /dev/null +++ b/3rdparty/asio/src/examples/cpp03/nonblocking/third_party_lib.cpp @@ -0,0 +1,240 @@ +// +// third_party_lib.cpp +// ~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2016 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) +// + +#include <asio.hpp> +#include <boost/array.hpp> +#include <boost/bind.hpp> +#include <boost/shared_ptr.hpp> +#include <boost/enable_shared_from_this.hpp> +#include <iostream> + +using asio::ip::tcp; + +namespace third_party_lib { + +// Simulation of a third party library that wants to perform read and write +// operations directly on a socket. It needs to be polled to determine whether +// it requires a read or write operation, and notified when the socket is ready +// for reading or writing. +class session +{ +public: + session(tcp::socket& socket) + : socket_(socket), + state_(reading) + { + } + + // Returns true if the third party library wants to be notified when the + // socket is ready for reading. + bool want_read() const + { + return state_ == reading; + } + + // Notify that third party library that it should perform its read operation. + void do_read(asio::error_code& ec) + { + if (std::size_t len = socket_.read_some(asio::buffer(data_), ec)) + { + write_buffer_ = asio::buffer(data_, len); + state_ = writing; + } + } + + // Returns true if the third party library wants to be notified when the + // socket is ready for writing. + bool want_write() const + { + return state_ == writing; + } + + // Notify that third party library that it should perform its write operation. + void do_write(asio::error_code& ec) + { + if (std::size_t len = socket_.write_some( + asio::buffer(write_buffer_), ec)) + { + write_buffer_ = write_buffer_ + len; + state_ = asio::buffer_size(write_buffer_) > 0 ? writing : reading; + } + } + +private: + tcp::socket& socket_; + enum { reading, writing } state_; + boost::array<char, 128> data_; + asio::const_buffer write_buffer_; +}; + +} // namespace third_party_lib + +// The glue between asio's sockets and the third party library. +class connection + : public boost::enable_shared_from_this<connection> +{ +public: + typedef boost::shared_ptr<connection> pointer; + + static pointer create(asio::io_context& io_context) + { + return pointer(new connection(io_context)); + } + + tcp::socket& socket() + { + return socket_; + } + + void start() + { + // Put the socket into non-blocking mode. + socket_.non_blocking(true); + + start_operations(); + } + +private: + connection(asio::io_context& io_context) + : socket_(io_context), + session_impl_(socket_), + read_in_progress_(false), + write_in_progress_(false) + { + } + + void start_operations() + { + // Start a read operation if the third party library wants one. + if (session_impl_.want_read() && !read_in_progress_) + { + read_in_progress_ = true; + socket_.async_wait(tcp::socket::wait_read, + boost::bind(&connection::handle_read, + shared_from_this(), + asio::placeholders::error)); + } + + // Start a write operation if the third party library wants one. + if (session_impl_.want_write() && !write_in_progress_) + { + write_in_progress_ = true; + socket_.async_wait(tcp::socket::wait_write, + boost::bind(&connection::handle_write, + shared_from_this(), + asio::placeholders::error)); + } + } + + void handle_read(asio::error_code ec) + { + read_in_progress_ = false; + + // Notify third party library that it can perform a read. + if (!ec) + session_impl_.do_read(ec); + + // The third party library successfully performed a read on the socket. + // Start new read or write operations based on what it now wants. + if (!ec || ec == asio::error::would_block) + start_operations(); + + // Otherwise, an error occurred. Closing the socket cancels any outstanding + // asynchronous read or write operations. The connection object will be + // destroyed automatically once those outstanding operations complete. + else + socket_.close(); + } + + void handle_write(asio::error_code ec) + { + write_in_progress_ = false; + + // Notify third party library that it can perform a write. + if (!ec) + session_impl_.do_write(ec); + + // The third party library successfully performed a write on the socket. + // Start new read or write operations based on what it now wants. + if (!ec || ec == asio::error::would_block) + start_operations(); + + // Otherwise, an error occurred. Closing the socket cancels any outstanding + // asynchronous read or write operations. The connection object will be + // destroyed automatically once those outstanding operations complete. + else + socket_.close(); + } + +private: + tcp::socket socket_; + third_party_lib::session session_impl_; + bool read_in_progress_; + bool write_in_progress_; +}; + +class server +{ +public: + server(asio::io_context& io_context, unsigned short port) + : acceptor_(io_context, tcp::endpoint(tcp::v4(), port)) + { + start_accept(); + } + +private: + void start_accept() + { + connection::pointer new_connection = + connection::create(acceptor_.get_executor().context()); + + acceptor_.async_accept(new_connection->socket(), + boost::bind(&server::handle_accept, this, new_connection, + asio::placeholders::error)); + } + + void handle_accept(connection::pointer new_connection, + const asio::error_code& error) + { + if (!error) + { + new_connection->start(); + } + + start_accept(); + } + + tcp::acceptor acceptor_; +}; + +int main(int argc, char* argv[]) +{ + try + { + if (argc != 2) + { + std::cerr << "Usage: third_party_lib <port>\n"; + return 1; + } + + asio::io_context io_context; + + using namespace std; // For atoi. + server s(io_context, atoi(argv[1])); + + io_context.run(); + } + catch (std::exception& e) + { + std::cerr << "Exception: " << e.what() << "\n"; + } + + return 0; +} |