5 // Copyright (c) 2003-2016 Christopher M. Kohlhoff (chris at kohlhoff dot com)
7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
11 #include <boost/asio.hpp>
12 #include <boost/bind.hpp>
13 #include <boost/shared_ptr.hpp>
19 #include "protocol.hpp"
21 using boost::asio::ip::tcp
;
22 using boost::asio::ip::udp
;
24 typedef boost::shared_ptr
<tcp::socket
> tcp_socket_ptr
;
25 typedef boost::shared_ptr
<boost::asio::deadline_timer
> timer_ptr
;
26 typedef boost::shared_ptr
<control_request
> control_request_ptr
;
31 // Construct the server to wait for incoming control connections.
32 server(boost::asio::io_service
& io_service
, unsigned short port
)
33 : acceptor_(io_service
, tcp::endpoint(tcp::v4(), port
)),
35 udp_socket_(io_service
, udp::endpoint(udp::v4(), 0)),
38 // Start waiting for a new control connection.
39 tcp_socket_ptr
new_socket(new tcp::socket(acceptor_
.get_io_service()));
40 acceptor_
.async_accept(*new_socket
,
41 boost::bind(&server::handle_accept
, this,
42 boost::asio::placeholders::error
, new_socket
));
44 // Start the timer used to generate outgoing frames.
45 timer_
.expires_from_now(boost::posix_time::milliseconds(100));
46 timer_
.async_wait(boost::bind(&server::handle_timer
, this));
49 // Handle a new control connection.
50 void handle_accept(const boost::system::error_code
& ec
, tcp_socket_ptr socket
)
54 // Start receiving control requests on the connection.
55 control_request_ptr
request(new control_request
);
56 boost::asio::async_read(*socket
, request
->to_buffers(),
57 boost::bind(&server::handle_control_request
, this,
58 boost::asio::placeholders::error
, socket
, request
));
61 // Start waiting for a new control connection.
62 tcp_socket_ptr
new_socket(new tcp::socket(acceptor_
.get_io_service()));
63 acceptor_
.async_accept(*new_socket
,
64 boost::bind(&server::handle_accept
, this,
65 boost::asio::placeholders::error
, new_socket
));
68 // Handle a new control request.
69 void handle_control_request(const boost::system::error_code
& ec
,
70 tcp_socket_ptr socket
, control_request_ptr request
)
74 // Delay handling of the control request to simulate network latency.
75 timer_ptr
delay_timer(
76 new boost::asio::deadline_timer(acceptor_
.get_io_service()));
77 delay_timer
->expires_from_now(boost::posix_time::seconds(2));
78 delay_timer
->async_wait(
79 boost::bind(&server::handle_control_request_timer
, this,
80 socket
, request
, delay_timer
));
84 void handle_control_request_timer(tcp_socket_ptr socket
,
85 control_request_ptr request
, timer_ptr
/*delay_timer*/)
87 // Determine what address this client is connected from, since
88 // subscriptions must be stored on the server as a complete endpoint, not
89 // just a port. We use the non-throwing overload of remote_endpoint() since
90 // it may fail if the socket is no longer connected.
91 boost::system::error_code ec
;
92 tcp::endpoint remote_endpoint
= socket
->remote_endpoint(ec
);
95 // Remove old port subscription, if any.
96 if (unsigned short old_port
= request
->old_port())
98 udp::endpoint
old_endpoint(remote_endpoint
.address(), old_port
);
99 subscribers_
.erase(old_endpoint
);
100 std::cout
<< "Removing subscription " << old_endpoint
<< std::endl
;
103 // Add new port subscription, if any.
104 if (unsigned short new_port
= request
->new_port())
106 udp::endpoint
new_endpoint(remote_endpoint
.address(), new_port
);
107 subscribers_
.insert(new_endpoint
);
108 std::cout
<< "Adding subscription " << new_endpoint
<< std::endl
;
112 // Wait for next control request on this connection.
113 boost::asio::async_read(*socket
, request
->to_buffers(),
114 boost::bind(&server::handle_control_request
, this,
115 boost::asio::placeholders::error
, socket
, request
));
118 // Every time the timer fires we will generate a new frame and send it to all
123 double x
= next_frame_number_
* 0.2;
124 double y
= std::sin(x
);
125 int char_index
= static_cast<int>((y
+ 1.0) * (frame::payload_size
/ 2));
127 for (int i
= 0; i
< frame::payload_size
; ++i
)
128 payload
+= (i
== char_index
? '*' : '.');
130 // Create the frame to be sent to all subscribers.
131 frame
f(next_frame_number_
++, payload
);
133 // Send frame to all subscribers. We can use synchronous calls here since
134 // UDP send operations typically do not block.
135 std::set
<udp::endpoint
>::iterator j
;
136 for (j
= subscribers_
.begin(); j
!= subscribers_
.end(); ++j
)
138 boost::system::error_code ec
;
139 udp_socket_
.send_to(f
.to_buffers(), *j
, 0, ec
);
142 // Wait for next timeout.
143 timer_
.expires_from_now(boost::posix_time::milliseconds(100));
144 timer_
.async_wait(boost::bind(&server::handle_timer
, this));
148 // The acceptor used to accept incoming control connections.
149 tcp::acceptor acceptor_
;
151 // The timer used for generating data.
152 boost::asio::deadline_timer timer_
;
154 // The socket used to send data to subscribers.
155 udp::socket udp_socket_
;
157 // The next frame number.
158 unsigned long next_frame_number_
;
160 // The set of endpoints that are subscribed.
161 std::set
<udp::endpoint
> subscribers_
;
164 int main(int argc
, char* argv
[])
170 std::cerr
<< "Usage: server <port>\n";
174 boost::asio::io_service io_service
;
176 using namespace std
; // For atoi.
177 server
s(io_service
, atoi(argv
[1]));
181 catch (std::exception
& e
)
183 std::cerr
<< "Exception: " << e
.what() << std::endl
;