1 //
2 // tcp_server.cpp
3 // ~~~~~~~~~~~~~~
4 //
5 // Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com)
6 //
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)
9 //
10
11 #include <boost/asio/io_context.hpp>
12 #include <boost/asio/ip/tcp.hpp>
13 #include <boost/asio/read.hpp>
14 #include <boost/asio/write.hpp>
15 #include <boost/shared_ptr.hpp>
16 #include <cstdio>
17 #include <cstdlib>
18 #include <cstring>
19 #include <vector>
20
21 using boost::asio::ip::tcp;
22
23 #include <boost/asio/yield.hpp>
24
25 class tcp_server : boost::asio::coroutine
26 {
27 public:
tcp_server(tcp::acceptor & acceptor,std::size_t buf_size)28 tcp_server(tcp::acceptor& acceptor, std::size_t buf_size) :
29 acceptor_(acceptor),
30 socket_(acceptor_.get_executor()),
31 buffer_(buf_size)
32 {
33 }
34
operator ()(boost::system::error_code ec,std::size_t n=0)35 void operator()(boost::system::error_code ec, std::size_t n = 0)
36 {
37 reenter (this) for (;;)
38 {
39 yield acceptor_.async_accept(socket_, ref(this));
40
41 while (!ec)
42 {
43 yield boost::asio::async_read(socket_,
44 boost::asio::buffer(buffer_), ref(this));
45
46 if (!ec)
47 {
48 for (std::size_t i = 0; i < n; ++i) buffer_[i] = ~buffer_[i];
49
50 yield boost::asio::async_write(socket_,
51 boost::asio::buffer(buffer_), ref(this));
52 }
53 }
54
55 socket_.close();
56 }
57 }
58
59 struct ref
60 {
reftcp_server::ref61 explicit ref(tcp_server* p)
62 : p_(p)
63 {
64 }
65
operator ()tcp_server::ref66 void operator()(boost::system::error_code ec, std::size_t n = 0)
67 {
68 (*p_)(ec, n);
69 }
70
71 private:
72 tcp_server* p_;
73 };
74
75 private:
76 tcp::acceptor& acceptor_;
77 tcp::socket socket_;
78 std::vector<unsigned char> buffer_;
79 tcp::endpoint sender_;
80 };
81
82 #include <boost/asio/unyield.hpp>
83
main(int argc,char * argv[])84 int main(int argc, char* argv[])
85 {
86 if (argc != 5)
87 {
88 std::fprintf(stderr,
89 "Usage: tcp_server <port> <nconns> "
90 "<bufsize> {spin|block}\n");
91 return 1;
92 }
93
94 unsigned short port = static_cast<unsigned short>(std::atoi(argv[1]));
95 int max_connections = std::atoi(argv[2]);
96 std::size_t buf_size = std::atoi(argv[3]);
97 bool spin = (std::strcmp(argv[4], "spin") == 0);
98
99 boost::asio::io_context io_context(1);
100 tcp::acceptor acceptor(io_context, tcp::endpoint(tcp::v4(), port));
101 std::vector<boost::shared_ptr<tcp_server> > servers;
102
103 for (int i = 0; i < max_connections; ++i)
104 {
105 boost::shared_ptr<tcp_server> s(new tcp_server(acceptor, buf_size));
106 servers.push_back(s);
107 (*s)(boost::system::error_code());
108 }
109
110 if (spin)
111 for (;;) io_context.poll();
112 else
113 io_context.run();
114 }
115