diff options
Diffstat (limited to '3rdparty/asio/src/examples/cpp03/timeouts')
5 files changed, 0 insertions, 1290 deletions
diff --git a/3rdparty/asio/src/examples/cpp03/timeouts/async_tcp_client.cpp b/3rdparty/asio/src/examples/cpp03/timeouts/async_tcp_client.cpp deleted file mode 100644 index fe2d27fac9e..00000000000 --- a/3rdparty/asio/src/examples/cpp03/timeouts/async_tcp_client.cpp +++ /dev/null @@ -1,311 +0,0 @@ -// -// async_tcp_client.cpp -// ~~~~~~~~~~~~~~~~~~~~ -// -// Copyright (c) 2003-2021 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/buffer.hpp" -#include "asio/io_context.hpp" -#include "asio/ip/tcp.hpp" -#include "asio/read_until.hpp" -#include "asio/steady_timer.hpp" -#include "asio/write.hpp" -#include <boost/bind/bind.hpp> -#include <iostream> -#include <string> - -using asio::steady_timer; -using asio::ip::tcp; - -// -// This class manages socket timeouts by applying the concept of a deadline. -// Some asynchronous operations are given deadlines by which they must complete. -// Deadlines are enforced by an "actor" that persists for the lifetime of the -// client object: -// -// +----------------+ -// | | -// | check_deadline |<---+ -// | | | -// +----------------+ | async_wait() -// | | -// +---------+ -// -// If the deadline actor determines that the deadline has expired, the socket -// is closed and any outstanding operations are consequently cancelled. -// -// Connection establishment involves trying each endpoint in turn until a -// connection is successful, or the available endpoints are exhausted. If the -// deadline actor closes the socket, the connect actor is woken up and moves to -// the next endpoint. -// -// +---------------+ -// | | -// | start_connect |<---+ -// | | | -// +---------------+ | -// | | -// async_- | +----------------+ -// connect() | | | -// +--->| handle_connect | -// | | -// +----------------+ -// : -// Once a connection is : -// made, the connect : -// actor forks in two - : -// : -// an actor for reading : and an actor for -// inbound messages: : sending heartbeats: -// : -// +------------+ : +-------------+ -// | |<- - - - -+- - - - ->| | -// | start_read | | start_write |<---+ -// | |<---+ | | | -// +------------+ | +-------------+ | async_wait() -// | | | | -// async_- | +-------------+ async_- | +--------------+ -// read_- | | | write() | | | -// until() +--->| handle_read | +--->| handle_write | -// | | | | -// +-------------+ +--------------+ -// -// The input actor reads messages from the socket, where messages are delimited -// by the newline character. The deadline for a complete message is 30 seconds. -// -// The heartbeat actor sends a heartbeat (a message that consists of a single -// newline character) every 10 seconds. In this example, no deadline is applied -// to message sending. -// -class client -{ -public: - client(asio::io_context& io_context) - : stopped_(false), - socket_(io_context), - deadline_(io_context), - heartbeat_timer_(io_context) - { - } - - // Called by the user of the client class to initiate the connection process. - // The endpoints will have been obtained using a tcp::resolver. - void start(tcp::resolver::results_type endpoints) - { - // Start the connect actor. - endpoints_ = endpoints; - start_connect(endpoints_.begin()); - - // Start the deadline actor. You will note that we're not setting any - // particular deadline here. Instead, the connect and input actors will - // update the deadline prior to each asynchronous operation. - deadline_.async_wait(boost::bind(&client::check_deadline, this)); - } - - // This function terminates all the actors to shut down the connection. It - // may be called by the user of the client class, or by the class itself in - // response to graceful termination or an unrecoverable error. - void stop() - { - stopped_ = true; - asio::error_code ignored_ec; - socket_.close(ignored_ec); - deadline_.cancel(); - heartbeat_timer_.cancel(); - } - -private: - void start_connect(tcp::resolver::results_type::iterator endpoint_iter) - { - if (endpoint_iter != endpoints_.end()) - { - std::cout << "Trying " << endpoint_iter->endpoint() << "...\n"; - - // Set a deadline for the connect operation. - deadline_.expires_after(asio::chrono::seconds(60)); - - // Start the asynchronous connect operation. - socket_.async_connect(endpoint_iter->endpoint(), - boost::bind(&client::handle_connect, this, - boost::placeholders::_1, endpoint_iter)); - } - else - { - // There are no more endpoints to try. Shut down the client. - stop(); - } - } - - void handle_connect(const asio::error_code& ec, - tcp::resolver::results_type::iterator endpoint_iter) - { - if (stopped_) - return; - - // The async_connect() function automatically opens the socket at the start - // of the asynchronous operation. If the socket is closed at this time then - // the timeout handler must have run first. - if (!socket_.is_open()) - { - std::cout << "Connect timed out\n"; - - // Try the next available endpoint. - start_connect(++endpoint_iter); - } - - // Check if the connect operation failed before the deadline expired. - else if (ec) - { - std::cout << "Connect error: " << ec.message() << "\n"; - - // We need to close the socket used in the previous connection attempt - // before starting a new one. - socket_.close(); - - // Try the next available endpoint. - start_connect(++endpoint_iter); - } - - // Otherwise we have successfully established a connection. - else - { - std::cout << "Connected to " << endpoint_iter->endpoint() << "\n"; - - // Start the input actor. - start_read(); - - // Start the heartbeat actor. - start_write(); - } - } - - void start_read() - { - // Set a deadline for the read operation. - deadline_.expires_after(asio::chrono::seconds(30)); - - // Start an asynchronous operation to read a newline-delimited message. - asio::async_read_until(socket_, - asio::dynamic_buffer(input_buffer_), '\n', - boost::bind(&client::handle_read, this, - boost::placeholders::_1, boost::placeholders::_2)); - } - - void handle_read(const asio::error_code& ec, std::size_t n) - { - if (stopped_) - return; - - if (!ec) - { - // Extract the newline-delimited message from the buffer. - std::string line(input_buffer_.substr(0, n - 1)); - input_buffer_.erase(0, n); - - // Empty messages are heartbeats and so ignored. - if (!line.empty()) - { - std::cout << "Received: " << line << "\n"; - } - - start_read(); - } - else - { - std::cout << "Error on receive: " << ec.message() << "\n"; - - stop(); - } - } - - void start_write() - { - if (stopped_) - return; - - // Start an asynchronous operation to send a heartbeat message. - asio::async_write(socket_, asio::buffer("\n", 1), - boost::bind(&client::handle_write, this, boost::placeholders::_1)); - } - - void handle_write(const asio::error_code& ec) - { - if (stopped_) - return; - - if (!ec) - { - // Wait 10 seconds before sending the next heartbeat. - heartbeat_timer_.expires_after(asio::chrono::seconds(10)); - heartbeat_timer_.async_wait(boost::bind(&client::start_write, this)); - } - else - { - std::cout << "Error on heartbeat: " << ec.message() << "\n"; - - stop(); - } - } - - void check_deadline() - { - if (stopped_) - return; - - // Check whether the deadline has passed. We compare the deadline against - // the current time since a new asynchronous operation may have moved the - // deadline before this actor had a chance to run. - if (deadline_.expiry() <= steady_timer::clock_type::now()) - { - // The deadline has passed. The socket is closed so that any outstanding - // asynchronous operations are cancelled. - socket_.close(); - - // There is no longer an active deadline. The expiry is set to the - // maximum time point so that the actor takes no action until a new - // deadline is set. - deadline_.expires_at(steady_timer::time_point::max()); - } - - // Put the actor back to sleep. - deadline_.async_wait(boost::bind(&client::check_deadline, this)); - } - -private: - bool stopped_; - tcp::resolver::results_type endpoints_; - tcp::socket socket_; - std::string input_buffer_; - steady_timer deadline_; - steady_timer heartbeat_timer_; -}; - -int main(int argc, char* argv[]) -{ - try - { - if (argc != 3) - { - std::cerr << "Usage: client <host> <port>\n"; - return 1; - } - - asio::io_context io_context; - tcp::resolver r(io_context); - client c(io_context); - - c.start(r.resolve(argv[1], argv[2])); - - io_context.run(); - } - catch (std::exception& e) - { - std::cerr << "Exception: " << e.what() << "\n"; - } - - return 0; -} diff --git a/3rdparty/asio/src/examples/cpp03/timeouts/blocking_tcp_client.cpp b/3rdparty/asio/src/examples/cpp03/timeouts/blocking_tcp_client.cpp deleted file mode 100644 index 67d0bcc7604..00000000000 --- a/3rdparty/asio/src/examples/cpp03/timeouts/blocking_tcp_client.cpp +++ /dev/null @@ -1,191 +0,0 @@ -// -// blocking_tcp_client.cpp -// ~~~~~~~~~~~~~~~~~~~~~~~ -// -// Copyright (c) 2003-2021 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/buffer.hpp" -#include "asio/connect.hpp" -#include "asio/io_context.hpp" -#include "asio/ip/tcp.hpp" -#include "asio/read_until.hpp" -#include "asio/system_error.hpp" -#include "asio/write.hpp" -#include <cstdlib> -#include <iostream> -#include <string> -#include <boost/lambda/bind.hpp> -#include <boost/lambda/lambda.hpp> - -using asio::ip::tcp; -using boost::lambda::bind; -using boost::lambda::var; -using boost::lambda::_1; -using boost::lambda::_2; - -//---------------------------------------------------------------------- - -// -// This class manages socket timeouts by running the io_context using the timed -// io_context::run_for() member function. Each asynchronous operation is given -// a timeout within which it must complete. The socket operations themselves -// use boost::lambda function objects as completion handlers. For a given -// socket operation, the client object runs the io_context to block thread -// execution until the operation completes or the timeout is reached. If the -// io_context::run_for() function times out, the socket is closed and the -// outstanding asynchronous operation is cancelled. -// -class client -{ -public: - client() - : socket_(io_context_) - { - } - - void connect(const std::string& host, const std::string& service, - asio::chrono::steady_clock::duration timeout) - { - // Resolve the host name and service to a list of endpoints. - tcp::resolver::results_type endpoints = - tcp::resolver(io_context_).resolve(host, service); - - // Start the asynchronous operation itself. The boost::lambda function - // object is used as a callback and will update the ec variable when the - // operation completes. The blocking_udp_client.cpp example shows how you - // can use boost::bind rather than boost::lambda. - asio::error_code ec; - asio::async_connect(socket_, endpoints, var(ec) = _1); - - // Run the operation until it completes, or until the timeout. - run(timeout); - - // Determine whether a connection was successfully established. - if (ec) - throw asio::system_error(ec); - } - - std::string read_line(asio::chrono::steady_clock::duration timeout) - { - // Start the asynchronous operation. The boost::lambda function object is - // used as a callback and will update the ec variable when the operation - // completes. The blocking_udp_client.cpp example shows how you can use - // boost::bind rather than boost::lambda. - asio::error_code ec; - std::size_t n = 0; - asio::async_read_until(socket_, - asio::dynamic_buffer(input_buffer_), - '\n', (var(ec) = _1, var(n) = _2)); - - // Run the operation until it completes, or until the timeout. - run(timeout); - - // Determine whether the read completed successfully. - if (ec) - throw asio::system_error(ec); - - std::string line(input_buffer_.substr(0, n - 1)); - input_buffer_.erase(0, n); - return line; - } - - void write_line(const std::string& line, - asio::chrono::steady_clock::duration timeout) - { - std::string data = line + "\n"; - - // Start the asynchronous operation. The boost::lambda function object is - // used as a callback and will update the ec variable when the operation - // completes. The blocking_udp_client.cpp example shows how you can use - // boost::bind rather than boost::lambda. - asio::error_code ec; - asio::async_write(socket_, asio::buffer(data), var(ec) = _1); - - // Run the operation until it completes, or until the timeout. - run(timeout); - - // Determine whether the read completed successfully. - if (ec) - throw asio::system_error(ec); - } - -private: - void run(asio::chrono::steady_clock::duration timeout) - { - // Restart the io_context, as it may have been left in the "stopped" state - // by a previous operation. - io_context_.restart(); - - // Block until the asynchronous operation has completed, or timed out. If - // the pending asynchronous operation is a composed operation, the deadline - // applies to the entire operation, rather than individual operations on - // the socket. - io_context_.run_for(timeout); - - // If the asynchronous operation completed successfully then the io_context - // would have been stopped due to running out of work. If it was not - // stopped, then the io_context::run_for call must have timed out. - if (!io_context_.stopped()) - { - // Close the socket to cancel the outstanding asynchronous operation. - socket_.close(); - - // Run the io_context again until the operation completes. - io_context_.run(); - } - } - - asio::io_context io_context_; - tcp::socket socket_; - std::string input_buffer_; -}; - -//---------------------------------------------------------------------- - -int main(int argc, char* argv[]) -{ - try - { - if (argc != 4) - { - std::cerr << "Usage: blocking_tcp_client <host> <port> <message>\n"; - return 1; - } - - client c; - c.connect(argv[1], argv[2], asio::chrono::seconds(10)); - - asio::chrono::steady_clock::time_point time_sent = - asio::chrono::steady_clock::now(); - - c.write_line(argv[3], asio::chrono::seconds(10)); - - for (;;) - { - std::string line = c.read_line(asio::chrono::seconds(10)); - - // Keep going until we get back the line that was sent. - if (line == argv[3]) - break; - } - - asio::chrono::steady_clock::time_point time_received = - asio::chrono::steady_clock::now(); - - std::cout << "Round trip time: "; - std::cout << asio::chrono::duration_cast< - asio::chrono::microseconds>( - time_received - time_sent).count(); - std::cout << " microseconds\n"; - } - catch (std::exception& e) - { - std::cerr << "Exception: " << e.what() << "\n"; - } - - return 0; -} diff --git a/3rdparty/asio/src/examples/cpp03/timeouts/blocking_token_tcp_client.cpp b/3rdparty/asio/src/examples/cpp03/timeouts/blocking_token_tcp_client.cpp deleted file mode 100644 index 45b56cb0263..00000000000 --- a/3rdparty/asio/src/examples/cpp03/timeouts/blocking_token_tcp_client.cpp +++ /dev/null @@ -1,201 +0,0 @@ -// -// blocking_token_tcp_client.cpp -// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -// -// Copyright (c) 2003-2021 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/connect.hpp" -#include "asio/io_context.hpp" -#include "asio/ip/tcp.hpp" -#include "asio/read_until.hpp" -#include "asio/streambuf.hpp" -#include "asio/system_error.hpp" -#include "asio/write.hpp" -#include <cstdlib> -#include <iostream> -#include <memory> -#include <string> - -using asio::ip::tcp; - -// We will use our sockets only with an io_context. -typedef asio::basic_stream_socket<tcp, - asio::io_context::executor_type> tcp_socket; - -//---------------------------------------------------------------------- - -// A custom completion token that makes asynchronous operations behave as -// though they are blocking calls with a timeout. -struct close_after -{ - close_after(asio::chrono::steady_clock::duration t, tcp_socket& s) - : timeout_(t), socket_(s) - { - } - - // The maximum time to wait for an asynchronous operation to complete. - asio::chrono::steady_clock::duration timeout_; - - // The socket to be closed if the operation does not complete in time. - tcp_socket& socket_; -}; - -namespace asio { - -// The async_result template is specialised to allow the close_after token to -// be used with asynchronous operations that have a completion signature of -// void(error_code, T). Generalising this for all completion signature forms is -// left as an exercise for the reader. -template <typename T> -class async_result<close_after, void(asio::error_code, T)> -{ -public: - // An asynchronous operation's initiating function automatically creates an - // completion_handler_type object from the token. This function object is - // then called on completion of the asynchronous operation. - class completion_handler_type - { - public: - completion_handler_type(const close_after& token) - : token_(token) - { - } - - void operator()(asio::error_code ec, T t) - { - *ec_ = ec; - *t_ = t; - } - - private: - friend class async_result; - close_after token_; - asio::error_code* ec_; - T* t_; - }; - - // The async_result constructor associates the completion handler object with - // the result of the initiating function. - explicit async_result(completion_handler_type& h) - : timeout_(h.token_.timeout_), - socket_(h.token_.socket_) - { - h.ec_ = &ec_; - h.t_ = &t_; - } - - // The return_type typedef determines the result type of the asynchronous - // operation's initiating function. - typedef T return_type; - - // The get() function is used to obtain the result of the asynchronous - // operation's initiating function. For the close_after completion token, we - // use this function to run the io_context until the operation is complete. - return_type get() - { - asio::io_context& io_context = asio::query( - socket_.get_executor(), asio::execution::context); - - // Restart the io_context, as it may have been left in the "stopped" state - // by a previous operation. - io_context.restart(); - - // Block until the asynchronous operation has completed, or timed out. If - // the pending asynchronous operation is a composed operation, the deadline - // applies to the entire operation, rather than individual operations on - // the socket. - io_context.run_for(timeout_); - - // If the asynchronous operation completed successfully then the io_context - // would have been stopped due to running out of work. If it was not - // stopped, then the io_context::run_for call must have timed out and the - // operation is still incomplete. - if (!io_context.stopped()) - { - // Close the socket to cancel the outstanding asynchronous operation. - socket_.close(); - - // Run the io_context again until the operation completes. - io_context.run(); - } - - // If the operation failed, throw an exception. Otherwise return the result. - return ec_ ? throw asio::system_error(ec_) : t_; - } - -private: - asio::chrono::steady_clock::duration timeout_; - tcp_socket& socket_; - asio::error_code ec_; - T t_; -}; - -} // namespace asio - -//---------------------------------------------------------------------- - -int main(int argc, char* argv[]) -{ - try - { - if (argc != 4) - { - std::cerr << "Usage: blocking_tcp_client <host> <port> <message>\n"; - return 1; - } - - asio::io_context io_context; - - // Resolve the host name and service to a list of endpoints. - tcp::resolver::results_type endpoints = - tcp::resolver(io_context).resolve(argv[1], argv[2]); - - tcp_socket socket(io_context); - - // Run an asynchronous connect operation with a timeout. - asio::async_connect(socket, endpoints, - close_after(asio::chrono::seconds(10), socket)); - - asio::chrono::steady_clock::time_point time_sent = - asio::chrono::steady_clock::now(); - - // Run an asynchronous write operation with a timeout. - std::string msg = argv[3] + std::string("\n"); - asio::async_write(socket, asio::buffer(msg), - close_after(asio::chrono::seconds(10), socket)); - - for (std::string input_buffer;;) - { - // Run an asynchronous read operation with a timeout. - std::size_t n = asio::async_read_until(socket, - asio::dynamic_buffer(input_buffer), '\n', - close_after(asio::chrono::seconds(10), socket)); - - std::string line(input_buffer.substr(0, n - 1)); - input_buffer.erase(0, n); - - // Keep going until we get back the line that was sent. - if (line == argv[3]) - break; - } - - asio::chrono::steady_clock::time_point time_received = - asio::chrono::steady_clock::now(); - - std::cout << "Round trip time: "; - std::cout << asio::chrono::duration_cast< - asio::chrono::microseconds>( - time_received - time_sent).count(); - std::cout << " microseconds\n"; - } - catch (std::exception& e) - { - std::cerr << "Exception: " << e.what() << "\n"; - } - - return 0; -} diff --git a/3rdparty/asio/src/examples/cpp03/timeouts/blocking_udp_client.cpp b/3rdparty/asio/src/examples/cpp03/timeouts/blocking_udp_client.cpp deleted file mode 100644 index 43b55ef43ff..00000000000 --- a/3rdparty/asio/src/examples/cpp03/timeouts/blocking_udp_client.cpp +++ /dev/null @@ -1,154 +0,0 @@ -// -// blocking_udp_client.cpp -// ~~~~~~~~~~~~~~~~~~~~~~~ -// -// Copyright (c) 2003-2021 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/buffer.hpp" -#include "asio/io_context.hpp" -#include "asio/ip/udp.hpp" -#include <cstdlib> -#include <boost/bind/bind.hpp> -#include <iostream> - -using asio::ip::udp; - -//---------------------------------------------------------------------- - -// -// This class manages socket timeouts by running the io_context using the timed -// io_context::run_for() member function. Each asynchronous operation is given -// a timeout within which it must complete. The socket operations themselves -// use boost::bind to specify the completion handler: -// -// +---------------+ -// | | -// | receive | -// | | -// +---------------+ -// | -// async_- | +----------------+ -// receive() | | | -// +--->| handle_receive | -// | | -// +----------------+ -// -// For a given socket operation, the client object runs the io_context to block -// thread execution until the operation completes or the timeout is reached. If -// the io_context::run_for() function times out, the socket is closed and the -// outstanding asynchronous operation is cancelled. -// -class client -{ -public: - client(const udp::endpoint& listen_endpoint) - : socket_(io_context_, listen_endpoint) - { - } - - std::size_t receive(const asio::mutable_buffer& buffer, - asio::chrono::steady_clock::duration timeout, - asio::error_code& ec) - { - // Start the asynchronous operation. The handle_receive function used as a - // callback will update the ec and length variables. - std::size_t length = 0; - socket_.async_receive(asio::buffer(buffer), - boost::bind(&client::handle_receive, - boost::placeholders::_1, boost::placeholders::_2, &ec, &length)); - - // Run the operation until it completes, or until the timeout. - run(timeout); - - return length; - } - -private: - void run(asio::chrono::steady_clock::duration timeout) - { - // Restart the io_context, as it may have been left in the "stopped" state - // by a previous operation. - io_context_.restart(); - - // Block until the asynchronous operation has completed, or timed out. If - // the pending asynchronous operation is a composed operation, the deadline - // applies to the entire operation, rather than individual operations on - // the socket. - io_context_.run_for(timeout); - - // If the asynchronous operation completed successfully then the io_context - // would have been stopped due to running out of work. If it was not - // stopped, then the io_context::run_for call must have timed out. - if (!io_context_.stopped()) - { - // Cancel the outstanding asynchronous operation. - socket_.cancel(); - - // Run the io_context again until the operation completes. - io_context_.run(); - } - } - - static void handle_receive( - const asio::error_code& ec, std::size_t length, - asio::error_code* out_ec, std::size_t* out_length) - { - *out_ec = ec; - *out_length = length; - } - -private: - asio::io_context io_context_; - udp::socket socket_; -}; - -//---------------------------------------------------------------------- - -int main(int argc, char* argv[]) -{ - try - { - using namespace std; // For atoi. - - if (argc != 3) - { - std::cerr << "Usage: blocking_udp_client <listen_addr> <listen_port>\n"; - return 1; - } - - udp::endpoint listen_endpoint( - asio::ip::make_address(argv[1]), - std::atoi(argv[2])); - - client c(listen_endpoint); - - for (;;) - { - char data[1024]; - asio::error_code ec; - std::size_t n = c.receive(asio::buffer(data), - asio::chrono::seconds(10), ec); - - if (ec) - { - std::cout << "Receive error: " << ec.message() << "\n"; - } - else - { - std::cout << "Received: "; - std::cout.write(data, n); - std::cout << "\n"; - } - } - } - catch (std::exception& e) - { - std::cerr << "Exception: " << e.what() << "\n"; - } - - return 0; -} diff --git a/3rdparty/asio/src/examples/cpp03/timeouts/server.cpp b/3rdparty/asio/src/examples/cpp03/timeouts/server.cpp deleted file mode 100644 index bee77d414a2..00000000000 --- a/3rdparty/asio/src/examples/cpp03/timeouts/server.cpp +++ /dev/null @@ -1,433 +0,0 @@ -// -// server.cpp -// ~~~~~~~~~~ -// -// Copyright (c) 2003-2021 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 <algorithm> -#include <cstdlib> -#include <deque> -#include <iostream> -#include <set> -#include <string> -#include <boost/bind/bind.hpp> -#include <boost/shared_ptr.hpp> -#include <boost/enable_shared_from_this.hpp> -#include "asio/buffer.hpp" -#include "asio/io_context.hpp" -#include "asio/ip/tcp.hpp" -#include "asio/ip/udp.hpp" -#include "asio/read_until.hpp" -#include "asio/steady_timer.hpp" -#include "asio/write.hpp" - -using asio::steady_timer; -using asio::ip::tcp; -using asio::ip::udp; - -//---------------------------------------------------------------------- - -class subscriber -{ -public: - virtual ~subscriber() {} - virtual void deliver(const std::string& msg) = 0; -}; - -typedef boost::shared_ptr<subscriber> subscriber_ptr; - -//---------------------------------------------------------------------- - -class channel -{ -public: - void join(subscriber_ptr subscriber) - { - subscribers_.insert(subscriber); - } - - void leave(subscriber_ptr subscriber) - { - subscribers_.erase(subscriber); - } - - void deliver(const std::string& msg) - { - std::for_each(subscribers_.begin(), subscribers_.end(), - boost::bind(&subscriber::deliver, - boost::placeholders::_1, boost::ref(msg))); - } - -private: - std::set<subscriber_ptr> subscribers_; -}; - -//---------------------------------------------------------------------- - -// -// This class manages socket timeouts by applying the concept of a deadline. -// Some asynchronous operations are given deadlines by which they must complete. -// Deadlines are enforced by two "actors" that persist for the lifetime of the -// session object, one for input and one for output: -// -// +----------------+ +----------------+ -// | | | | -// | check_deadline |<---+ | check_deadline |<---+ -// | | | async_wait() | | | async_wait() -// +----------------+ | on input +----------------+ | on output -// | | deadline | | deadline -// +---------+ +---------+ -// -// If either deadline actor determines that the corresponding deadline has -// expired, the socket is closed and any outstanding operations are cancelled. -// -// The input actor reads messages from the socket, where messages are delimited -// by the newline character: -// -// +------------+ -// | | -// | start_read |<---+ -// | | | -// +------------+ | -// | | -// async_- | +-------------+ -// read_- | | | -// until() +--->| handle_read | -// | | -// +-------------+ -// -// The deadline for receiving a complete message is 30 seconds. If a non-empty -// message is received, it is delivered to all subscribers. If a heartbeat (a -// message that consists of a single newline character) is received, a heartbeat -// is enqueued for the client, provided there are no other messages waiting to -// be sent. -// -// The output actor is responsible for sending messages to the client: -// -// +--------------+ -// | |<---------------------+ -// | await_output | | -// | |<---+ | -// +--------------+ | | -// | | | async_wait() | -// | +--------+ | -// V | -// +-------------+ +--------------+ -// | | async_write() | | -// | start_write |-------------->| handle_write | -// | | | | -// +-------------+ +--------------+ -// -// The output actor first waits for an output message to be enqueued. It does -// this by using a steady_timer as an asynchronous condition variable. The -// steady_timer will be signalled whenever the output queue is non-empty. -// -// Once a message is available, it is sent to the client. The deadline for -// sending a complete message is 30 seconds. After the message is successfully -// sent, the output actor again waits for the output queue to become non-empty. -// -class tcp_session - : public subscriber, - public boost::enable_shared_from_this<tcp_session> -{ -public: - tcp_session(asio::io_context& io_context, channel& ch) - : channel_(ch), - socket_(io_context), - input_deadline_(io_context), - non_empty_output_queue_(io_context), - output_deadline_(io_context) - { - input_deadline_.expires_at(steady_timer::time_point::max()); - output_deadline_.expires_at(steady_timer::time_point::max()); - - // The non_empty_output_queue_ steady_timer is set to the maximum time - // point whenever the output queue is empty. This ensures that the output - // actor stays asleep until a message is put into the queue. - non_empty_output_queue_.expires_at(steady_timer::time_point::max()); - } - - tcp::socket& socket() - { - return socket_; - } - - // Called by the server object to initiate the four actors. - void start() - { - channel_.join(shared_from_this()); - - start_read(); - - input_deadline_.async_wait( - boost::bind(&tcp_session::check_deadline, - shared_from_this(), &input_deadline_)); - - await_output(); - - output_deadline_.async_wait( - boost::bind(&tcp_session::check_deadline, - shared_from_this(), &output_deadline_)); - } - -private: - void stop() - { - channel_.leave(shared_from_this()); - - asio::error_code ignored_ec; - socket_.close(ignored_ec); - input_deadline_.cancel(); - non_empty_output_queue_.cancel(); - output_deadline_.cancel(); - } - - bool stopped() const - { - return !socket_.is_open(); - } - - void deliver(const std::string& msg) - { - output_queue_.push_back(msg + "\n"); - - // Signal that the output queue contains messages. Modifying the expiry - // will wake the output actor, if it is waiting on the timer. - non_empty_output_queue_.expires_at(steady_timer::time_point::min()); - } - - void start_read() - { - // Set a deadline for the read operation. - input_deadline_.expires_after(asio::chrono::seconds(30)); - - // Start an asynchronous operation to read a newline-delimited message. - asio::async_read_until(socket_, - asio::dynamic_buffer(input_buffer_), '\n', - boost::bind(&tcp_session::handle_read, shared_from_this(), - boost::placeholders::_1, boost::placeholders::_2)); - } - - void handle_read(const asio::error_code& ec, std::size_t n) - { - if (stopped()) - return; - - if (!ec) - { - // Extract the newline-delimited message from the buffer. - std::string msg(input_buffer_.substr(0, n - 1)); - input_buffer_.erase(0, n); - - if (!msg.empty()) - { - channel_.deliver(msg); - } - else - { - // We received a heartbeat message from the client. If there's nothing - // else being sent or ready to be sent, send a heartbeat right back. - if (output_queue_.empty()) - { - output_queue_.push_back("\n"); - - // Signal that the output queue contains messages. Modifying the - // expiry will wake the output actor, if it is waiting on the timer. - non_empty_output_queue_.expires_at(steady_timer::time_point::min()); - } - } - - start_read(); - } - else - { - stop(); - } - } - - void await_output() - { - if (stopped()) - return; - - if (output_queue_.empty()) - { - // There are no messages that are ready to be sent. The actor goes to - // sleep by waiting on the non_empty_output_queue_ timer. When a new - // message is added, the timer will be modified and the actor will wake. - non_empty_output_queue_.expires_at(steady_timer::time_point::max()); - non_empty_output_queue_.async_wait( - boost::bind(&tcp_session::await_output, shared_from_this())); - } - else - { - start_write(); - } - } - - void start_write() - { - // Set a deadline for the write operation. - output_deadline_.expires_after(asio::chrono::seconds(30)); - - // Start an asynchronous operation to send a message. - asio::async_write(socket_, - asio::buffer(output_queue_.front()), - boost::bind(&tcp_session::handle_write, - shared_from_this(), boost::placeholders::_1)); - } - - void handle_write(const asio::error_code& ec) - { - if (stopped()) - return; - - if (!ec) - { - output_queue_.pop_front(); - - await_output(); - } - else - { - stop(); - } - } - - void check_deadline(steady_timer* deadline) - { - if (stopped()) - return; - - // Check whether the deadline has passed. We compare the deadline against - // the current time since a new asynchronous operation may have moved the - // deadline before this actor had a chance to run. - if (deadline->expiry() <= steady_timer::clock_type::now()) - { - // The deadline has passed. Stop the session. The other actors will - // terminate as soon as possible. - stop(); - } - else - { - // Put the actor back to sleep. - deadline->async_wait( - boost::bind(&tcp_session::check_deadline, - shared_from_this(), deadline)); - } - } - - channel& channel_; - tcp::socket socket_; - std::string input_buffer_; - steady_timer input_deadline_; - std::deque<std::string> output_queue_; - steady_timer non_empty_output_queue_; - steady_timer output_deadline_; -}; - -typedef boost::shared_ptr<tcp_session> tcp_session_ptr; - -//---------------------------------------------------------------------- - -class udp_broadcaster - : public subscriber -{ -public: - udp_broadcaster(asio::io_context& io_context, - const udp::endpoint& broadcast_endpoint) - : socket_(io_context) - { - socket_.connect(broadcast_endpoint); - socket_.set_option(udp::socket::broadcast(true)); - } - -private: - void deliver(const std::string& msg) - { - asio::error_code ignored_ec; - socket_.send(asio::buffer(msg), 0, ignored_ec); - } - - udp::socket socket_; -}; - -//---------------------------------------------------------------------- - -class server -{ -public: - server(asio::io_context& io_context, - const tcp::endpoint& listen_endpoint, - const udp::endpoint& broadcast_endpoint) - : io_context_(io_context), - acceptor_(io_context, listen_endpoint) - { - subscriber_ptr bc(new udp_broadcaster(io_context_, broadcast_endpoint)); - channel_.join(bc); - - start_accept(); - } - - void start_accept() - { - tcp_session_ptr new_session(new tcp_session(io_context_, channel_)); - - acceptor_.async_accept(new_session->socket(), - boost::bind(&server::handle_accept, - this, new_session, boost::placeholders::_1)); - } - - void handle_accept(tcp_session_ptr session, - const asio::error_code& ec) - { - if (!ec) - { - session->start(); - } - - start_accept(); - } - -private: - asio::io_context& io_context_; - tcp::acceptor acceptor_; - channel channel_; -}; - -//---------------------------------------------------------------------- - -int main(int argc, char* argv[]) -{ - try - { - using namespace std; // For atoi. - - if (argc != 4) - { - std::cerr << "Usage: server <listen_port> <bcast_address> <bcast_port>\n"; - return 1; - } - - asio::io_context io_context; - - tcp::endpoint listen_endpoint(tcp::v4(), atoi(argv[1])); - - udp::endpoint broadcast_endpoint( - asio::ip::make_address(argv[2]), atoi(argv[3])); - - server s(io_context, listen_endpoint, broadcast_endpoint); - - io_context.run(); - } - catch (std::exception& e) - { - std::cerr << "Exception: " << e.what() << "\n"; - } - - return 0; -} |