Question

我正在使用pion网络库，使用其同步API，通过同步我的意思是在阻止模式下连接到服务器。问题是连接可能很长，所以我需要设置超时。

我搜索了很多东西并找到了一些东西：首先将套接字设置为非阻塞，然后连接，这是我的代码：

int main() {
    string ip = "65.233.167.165"; // some fake ip maybe not even exists
    int port = 80;

    boost::asio::io_service io_service;

    boost::asio::ip::address addr;
    addr = addr.from_string(ip);
    boost::asio::ip::tcp::endpoint endpoint(addr, port);

    // socket
    boost::asio::ip::tcp::socket s(io_service);

    s.open(boost::asio::ip::tcp::v4());  
    // set to non-blocking
    s.io_control(boost::asio::ip::tcp::socket::non_blocking_io(true));  

    fd_set fdWrite;  
    FD_ZERO(&fdWrite);  
    FD_SET(s.native(), &fdWrite);  
    timeval tv = {3}; // timeout after 3 seconds

    if (select(0, NULL, &fdWrite, NULL, &tv) <= 0   
        || !FD_ISSET(s.native(), &fdWrite))  
    {  
        std::cout << "TIMEOUT" << std::endl;  
        s.close();  
        return 0;  
    }  
    // set back to blocking
    s.io_control(boost::asio::ip::tcp::socket::non_blocking_io(false));

    // connect
    boost::system::error_code ec;
    s.connect(endpoint, ec);

    if(ec) {
        std::cout << "error: " << ec.message() << endl;
    }
}

它有效，所以我尝试用pion这个技巧。首先，将行65.233.167.165 www.mytest.org添加到etc / hosts以将域绑定到测试ip。然后是代码：

string host = "www.mytest.org"; 
int port = 80;

using namespace boost;
using boost::asio::ip::tcp;

pion::tcp::connection con(io_service, false);

con.get_socket().open(boost::asio::ip::tcp::v4());  
// set to non-blocking
con.get_socket().io_control(boost::asio::ip::tcp::socket::non_blocking_io(true)); 

cout << "now connect" << endl;
con.connect(host, port);

fd_set fdWrite;  
FD_ZERO(&fdWrite);  
FD_SET(con.get_socket().native(), &fdWrite);  
timeval tv = {3}; // 3 seconds timeout
if (select(0, NULL, &fdWrite, NULL, &tv) <= 0   
    || !FD_ISSET(con.get_socket().native(), &fdWrite))  
{  
    cout << "connect timeout" << endl;
    return 1;
}

cout << "connected or timeout" << endl;
// set back to blocking
con.get_socket().io_control(boost::asio::ip::tcp::socket::non_blocking_io(false));

超时不起作用。

有什么想法吗？感谢。

连接时在阻塞套接字上设置超时（使用pion c ++库）

0 个答案: