前几天在 Windows 编译了 asio-1.10.8\src\tests\latency\tcp_server.cpp,结果并不能正常工作,客户端连上来,发数据后就卡死了……
今天,重新思考用 aiso coroutine 来写个 echo server 练手,终于把这个 bug 解决了,具体见注释。
#include <asio/io_service.hpp>
#include <asio/ip/tcp.hpp>
#include <asio/read.hpp>
#include <asio/write.hpp>
#include <asio/yield.hpp>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <vector>
#include <iostream>
using asio::ip::tcp;
class tcp_server : asio::coroutine
{
public:
tcp_server(tcp::acceptor& acceptor, std::size_t buf_size) :
acceptor_(acceptor),
socket_(acceptor_.get_io_service()),
buffer_(buf_size)
{
}
void operator()(asio::error_code ec, std::size_t n = 0)
{
reenter(this) for (;;) {
yield acceptor_.async_accept(socket_, ref(this));
if (ec) {
std::cout << "[" << ec.value() << "]" << ec.message() << std::endl;
} else {
std::cout << "Connect from " << socket_.remote_endpoint() << std::endl;
}
while (!ec) {
// UMU: 下一行是 bug,会卡死!!!
//yield asio::async_read(socket_, asio::buffer(buffer_), ref(this));
yield socket_.async_read_some(asio::buffer(buffer_), ref(this));
if (ec) {
// UMU
std::cout << "[" << ec.value() << "]" << ec.message() << std::endl;
} else {
std::cout << "Read " << n << " from " << socket_.remote_endpoint() << ": ";
std::cout.write(reinterpret_cast<char *>(buffer_.data()), n);
std::cout << std::endl;
// UMU: 下面两种写法都可以
//yield asio::async_write(socket_, asio::buffer(buffer_, n), ref(this));
yield socket_.async_write_some(asio::buffer(buffer_, n), ref(this));
if (ec) {
std::cout << "[" << ec.value() << "]" << ec.message() << std::endl;
} else {
std::cout << "Write " << n << " to " << socket_.remote_endpoint() << std::endl;
}
}
}
socket_.close();
}
}
struct ref
{
explicit ref(tcp_server* p) : p_(p)
{
}
void operator()(asio::error_code ec, std::size_t n = 0)
{
// UMU: for debug
//std::cout << "#" << ec.value() << ", " << n << std::endl;
(*p_)(ec, n);
}
private:
tcp_server* p_;
};
private:
tcp::acceptor& acceptor_;
tcp::socket socket_;
std::vector<unsigned char> buffer_;
tcp::endpoint sender_;
};
#include <asio/unyield.hpp>
int main(int argc, char* argv[])
{
if (argc != 5) {
std::fprintf(stderr,
"Usage: tcp_server <port> <nconns> "
"<bufsize> {spin|block}\n");
return 1;
}
unsigned short port = static_cast<unsigned short>(std::atoi(argv[1]));
int max_connections = std::atoi(argv[2]);
std::size_t buf_size = std::atoi(argv[3]);
bool spin = (std::strcmp(argv[4], "spin") == 0);
asio::io_service io_service(1);
tcp::acceptor acceptor(io_service, tcp::endpoint(tcp::v4(), port));
//std::vector<boost::shared_ptr<tcp_server> > servers;
std::vector<std::shared_ptr<tcp_server> > servers;
for (int i = 0; i < max_connections; ++i) {
//boost::shared_ptr<tcp_server> s(new tcp_server(acceptor, buf_size));
std::shared_ptr<tcp_server> s(std::make_shared<tcp_server>(acceptor, buf_size));
servers.push_back(s);
(*s)(asio::error_code());
}
if (spin)
for (;;) io_service.poll(); // UMU: CPU 占用率很高
else
io_service.run();
}